0001437749-22-005888 | 10-K | XBRL Viewer | Acelrx Pharmaceuticals INC

Issuance of common stock upon ESPP purchase (in shares)

$ 19

21,318

21,337

340,128

Issuance of common stock upon ESPP purchase

$ 0

372

Net loss

$ 0

(40,379)

Balance (in shares) at Dec. 31, 2020

98,812,008

Balance at Dec. 31, 2020

$ 98

382,637

(438,485)

(55,750)

^[1]

Stock-based compensation

$ 0

4,609

Restricted stock units vested (in shares)

488,715

Restricted stock units vested

$ 0

(249)

Net proceeds from issuance of common stock in connection with equity financings (in shares)

37,201,562

Issuance of common stock upon ESPP purchase (in shares)

$ 38

44,678

44,716

297,959

Issuance of common stock upon ESPP purchase

$ 0

301

Net loss

(35,099)

Net proceeds from issuance of warrants in connection with equity financings

$ 0

5,562

$ 5,562

Issuance of common stock upon exercise of stock options (in shares)

19,403

Issuance of common stock upon exercise of stock options

$ 1

$ 17

Balance (in shares) at Dec. 31, 2021

136,819,647

Balance at Dec. 31, 2021

$ 137

$ 437,554

$ (473,584)

$ (35,893)

[1]	The condensed consolidated balance sheet as of December 31, 2020 has been derived from the audited financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020.

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (35,099)	$ (40,379)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash royalty revenue related to royalty monetization	(83)	(242)
Non-cash interest income on liability related to royalty monetization	(3,038)	(3,310)
Depreciation and amortization	1,973	1,853
Non-cash interest expense related to debt financing	761	1,069
Stock-based compensation	4,609	4,424
Inventory impairment charge	810	712
Other	(138)	(344)
Changes in operating assets and liabilities:
Accounts receivable	475	(203)
Inventories	(295)	957
Prepaid expenses and other assets	(908)	661
Accounts payable	111	1,016
Accrued liabilities	79	(638)
Operating lease liabilities	(447)	(886)
Deferred revenue	1,188	(3,195)
Net cash used in operating activities	(30,002)	(38,505)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(1,827)	(1,855)
Purchase of investments	(70,459)	(44,611)
Proceeds from sale of investments	2,996	0
Proceeds from maturities of investments	43,988	80,605
Net cash (used in) provided by investing activities	(26,123)	34,139
CASH FLOWS FROM FINANCING ACTIVITIES:
Payment of long-term debt	(8,833)	(4,667)
Net proceeds from issuance of common stock in connection with equity financings	44,716	21,337
Net proceeds from issuance of warrants in connection with equity financings	5,562	0
Net proceeds from issuance of common stock through equity plans	318	372
Tax payments related to shares withheld for restricted stock units vested	(249)	(86)
Net cash provided by financing activities	41,514	16,956
NET (DECREASE) INCREASE IN CASH, CASH EQUIVALENTS	(14,611)	12,590
CASH, CASH EQUIVALENTS —Beginning of year	27,274	14,684
CASH, CASH EQUIVALENTS —End of year	12,663	27,274
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for interest	1,595	2,269
Income taxes paid (refunded)	5	(347)
NONCASH INVESTING AND FINANCING ACTIVITIES:
Purchases of property and equipment in accounts payable and accrued expenses	1,095	0
Asset acquisition costs in accounts payable and accrued expenses	1,087	0
Establishment of right-of-use asset and lease liability	4,669	0
Write-off of right-of-use asset and lease liability	(3,128)	0
Gain on termination of sublease	522	0
Leasehold improvements paid with note payable	0	326
Lowell’s Intellectual Property [Member]
CASH FLOWS FROM INVESTING ACTIVITIES:
Asset acquisition costs	$ (821)	$ 0

Note 1 - Organization and Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2021

Basis of Presentation and Significant Accounting Policies [Text Block]

1. Organization and Summary of Significant Accounting Policies

The Company

AcelRx Pharmaceuticals, Inc., or the Company, or AcelRx, was incorporated in Delaware on July 13, 2005 as SuRx, Inc. The Company subsequently changed its name to AcelRx Pharmaceuticals, Inc. The Company’s operations are based in Hayward, California.

AcelRx is a specialty pharmaceutical company focused on the development and commercialization of innovative therapies for use in medically supervised settings. DSUVIA®(known as DZUVEO® in Europe) and Zalviso® areboth focused on the treatment of acute pain, and each utilize sufentanil, delivered via a non-invasive route of sublingual administration, exclusively for use in medically supervised settings. On November 2, 2018, the U.S. Food and Drug Administration, or FDA, approved DSUVIA for use in adults in a certified medically supervised healthcare setting, such as hospitals, surgical centers, and emergency departments, for the management of acute pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate. The commercial launch of DSUVIA in the United States occurred in the first quarter of 2019. In June 2018, the European Commission, or EC, granted marketing approval of DZUVEO for the management of acute moderate to severe pain in adults in medically monitored settings. AcelRx is further developing a distribution capability and commercial organization to continue to market and sell DSUVIA in the United States. In geographies where AcelRx decides not to commercialize products by itself, the Company may seek to out-license commercialization rights. The Company currently intends to commercialize and promote DSUVIA/DZUVEO outside the United States with one or more strategic partners, and, in July 2021, entered into a License and Commercialization Agreement with Laboratoire Aguettant, or Aguettant, for Aguettant to commercialize DZUVEO in the European Union, Norway, Iceland, Liechtenstein, Andorra, Vatican City, Monaco, Switzerland and the United Kingdom (see Note 6. “Out-License Agreements—DZUVEO” below). The timing of the resubmission of the Zalviso new drug application, or NDA, is in part dependent upon the finalization of the FDA’s new opioid approval guidelines and process. AcelRx intends to seek regulatory approval for Zalviso in the United States and, if successful, potentially promote Zalviso either by itself or with strategic partners. Zalviso is approved in Europe and was commercialized by Grünenthal GmbH, or Grünenthal, through May 12, 2021 (see Termination of Grünenthal Agreements below). In July 2021, the Company also entered into a separate License and Commercialization Agreement with Aguettant pursuant to which the Company obtained the exclusive right to develop and, subject to FDA approval, commercialize in the United States (i) an ephedrine pre-filled syringe containing 10 ml of a solution of 3 mg/ml ephedrine hydrochloride for injection, and (ii) a phenylephrine pre-filled syringe containing 10 ml of a solution of 50 mcg/ml phenylephrine hydrochloride for injection (see Note 5. “In-License Agreement” below). On January 7, 2022, the Company closed the definitive merger agreement dated as of November 14, 2021, or the Merger Agreement, to acquire Lowell Therapeutics, Inc., or Lowell, a privately held company (see Note 19. “Subsequent Events” below).

The Company has incurred recurring operating losses and negative cash flows from operating activities since inception. As of December 31, 2021 and December 31, 2020, the Company had cash, cash equivalents and short-term investments of $51.6 million and $42.9 million, respectively. Based on the Company’s current operating plans and projections, the Company expects that its existing cash, cash equivalents and short-term investments will be sufficient to fund operations for at least one year from the date this Annual Report on Form 10-K is filed with the United States Securities and Exchange Commission, or SEC. Although Zalviso was approved for sale in Europe on September 18, 2015, the Company sold the majority of the royalty rights and certain commercial sales milestones it is entitled to receive under the Amended License Agreement (defined below) with Grünenthal to PDL BioPharma, Inc., or PDL, in a transaction referred to as the Royalty Monetization. On August 31, 2020, PDL announced it sold its royalty interest for Zalviso to SWK Funding, LLC, or SWK. In consideration of the termination of the Amended License Agreement, under the Royalty Monetization, the Company must use commercially reasonable efforts to negotiate a replacement license agreement with a third party.

Termination of Grünenthal Agreements

On December 16, 2013, AcelRx and Grünenthal entered into a Collaboration and License Agreement, or the License Agreement, which was amended effective July 17, 2015 and September 20, 2016, or the Amended License Agreement, which granted Grünenthal rights to commercialize the Zalviso PCA system, or the Product, in the 28 European Union, or EU, member states, at the time of the agreement, plus Switzerland, Liechtenstein, Iceland, Norway and Australia (collectively, the Zalviso Territory) for human use in pain treatment within, or dispensed by, hospitals, hospices, nursing homes and other medically supervised settings, (collectively, the Field). In September 2015, the EC granted marketing approval for the marketing authorization application, or MAA, previously submitted to the EMA, for Zalviso for the management of acute moderate-to-severe post-operative pain in adult patients. On December 16, 2013, AcelRx and Grünenthal entered into a Manufacture and Supply Agreement, or the MSA, and together with the License Agreement, the Agreements. Under the MSA, the Company exclusively manufactured and supplied the Product to Grünenthal for the Field in the Zalviso Territory. On July 22, 2015, the Company and Grünenthal amended the MSA, or the Amended MSA, effective as of July 17, 2015. The Amended MSA and the Amended License Agreement are referred to as the Grünenthal Agreements.

On May 18, 2020, the Company received a notice from Grünenthal that it had exercised its right to terminate the Grünenthal Agreements, effective November 13, 2020. The terms of the Grünenthal Agreements were extended to May 12, 2021 to enable Grünenthal to sell down its Zalviso inventory, a right it had under the Grünenthal Agreements. The rights to market and sell Zalviso in the Zalviso Territory reverted back to the Company on May 12, 2021.

Basis of Presentation

The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the amounts reported in the Consolidated Financial Statements and the accompanying notes. Actual results could differ from those estimates.

Reclassifications

Certain prior year amounts in the Consolidated Financial Statements have been reclassified to conform to the current year's presentation. In particular, the amounts reported in the Consolidated Balance Sheets as deferred revenue, current portion and liability related to the sale of future royalties, current portion have been reclassified to accrued and other liabilities at December 31, 2020, and the amount reported as an inventory impairment charge in the Consolidated Statements of Cash Flows was recorded as other in the year ended December 31, 2020.

Principles of Consolidation

The Consolidated Financial Statements include the accounts of the Company and its wholly owned subsidiary, ARPI LLC, which was formed in September 2015 for the sole purpose of facilitating the Royalty Monetization with PDL of the expected royalty stream and milestone payments due from the sales of Zalviso in the European Union by its commercial partner, Grünenthal, pursuant to the Amended License Agreement. All intercompany accounts and transactions have been eliminated in consolidation. Refer to Note 10 “Liability Related to Sale of Future Royalties” for additional information.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the Consolidated Financial Statements and accompanying notes. Management believes its most significant accounting estimates relate to revenue recognition, inventory valuation and the liability related to the sale of future royalties. Management evaluates its estimates on an ongoing basis including critical accounting policies. Estimates are based on historical experience and on various other market-specific and other relevant assumptions that the Company believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ from those estimates.

Cash, Cash Equivalents and Short-Term Investments

The Company considers all highly liquid investments with an original maturity (at date of purchase) of three months or less to be cash equivalents. Cash and cash equivalents consist of cash on deposit with banks.

All marketable securities are classified as available-for-sale and consist of commercial paper, U.S. government sponsored enterprise debt securities and corporate debt securities. These securities are carried at estimated fair value, which is based on quoted market prices or observable market inputs of almost identical assets, with unrealized gains and losses included in accumulated other comprehensive income (loss). The amortized cost of securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion is included in interest income or expense. The cost of securities sold is based on specific identification. The Company’s investments are subject to a periodic impairment review for other-than-temporary declines in fair value. The Company’s review includes the consideration of the cause of the impairment including the creditworthiness of the security issuers, the number of securities in an unrealized loss position, the severity and duration of the unrealized losses and the Company’s intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in the market value. When the Company determines that the decline in fair value of an investment is below its accounting basis and this decline is other-than-temporary, it reduces the carrying value of the security it holds and records a loss in the amount of such decline.

Fair Value of Financial Instruments

The Company measures and reports its cash equivalents, investments and financial liabilities at fair value. Fair value is defined as the exchange price that would be received for an asset or an exit price paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The fair value hierarchy defines a three-level valuation hierarchy for disclosure of fair value measurements as follows:

Level I—Unadjusted quoted prices in active markets for identical assets or liabilities;

Level II—Inputs other than quoted prices included within Level I that are observable, unadjusted quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and

Level III—Unobservable inputs that are supported by little or no market activity for the related assets or liabilities.

The categorization of a financial instrument within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement.

Segment Information

The Company operates in a single segment, the development and commercialization of product candidates and products for the treatment of pain. The Company’s product sales revenue consists of sales of DSUVIA in the United States and, through May 2021, sales of Zalviso in Europe by Grünenthal. The Company’s contract and collaboration revenue consists of non-cash royalty revenue, royalty revenue, and other revenue under the Grünenthal Agreements and license revenue under the DZUVEO Agreement.

Concentration of Risk

The Company invests cash that is currently not being used for operational purposes in accordance with its investment policy in debt securities of U.S. government sponsored agencies, commercial paper and overnight deposits. The Company is exposed to credit risk in the event of default by the institutions holding the cash equivalents and available-for-sale securities to the extent recorded on the Consolidated Balance Sheets.

The Company relies on a single third-party supplier for the supply of sufentanil, the active pharmaceutical ingredient in DSUVIA and Zalviso, and various sole-source third-party contract manufacturer organizations to manufacture the DSUVIA SDA.

DSUVIA sales are concentrated with the DoD and with a limited number of wholesalers in the United States. Zalviso was sold in Europe by Grünenthal through May 2021. In July 2021, Aguettant was granted an exclusive license to commercialize DZUVEO in Europe. DZUVEO sales in Europe by Aguettant have not commenced as of December 31, 2021.

Revenue and accounts receivable have been concentrated with these customers.

Revenues from customers that accounted for 10% or more of our total revenues during the years ended December 31, 2021 and 2020 are as follows:

Year Ended December 31,

Percent of Total Revenue

2021

2020

Aguettant
61.9 % 0 %

Grünenthal
11.7 % 74.0 %

DoD
0.3 % 16.9 %

Wholesaler A
15.9 % 3.9 %

Accounts Receivable, net

The need for a bad debt allowance is evaluated each reporting period based on the Company’s assessment of the credit worthiness of its customers or any other potential circumstances that could result in bad debt.

The Company believes that the entire accounts receivable balance as of December 31, 2021 is collectible and there was no bad debt allowance provided as of December 31, 2020.

Accounts receivable, net from customers that accounted for 10% or more of our total accounts receivable balance as of December 31, 2021 and 2020 are as follows:

As of December 31,

Percent of Accounts Receivable, Net

2021

2020

Customer A
73 % 12 %

Customer B
0 % 79 %

Inventories, net

Inventories are valued at the lower of cost or net realizable value. Cost is determined using the first-in, first-out method for all inventories. Inventory includes the cost of the active pharmaceutical ingredients, or API, raw materials and third-party contract manufacturing and packaging services. Indirect overhead costs associated with production and distribution are allocated to the appropriate cost pool and then absorbed into inventory based on the units produced or distributed, assuming normal capacity, in the applicable period. Indirect overhead costs in excess of normal capacity are recorded as period costs in the period incurred.

The Company's policy is to write down inventory that has become obsolete, inventory that has a cost basis in excess of its expected net realizable value and inventory in excess of expected requirements. The Company periodically evaluates the carrying value of inventory on hand for potential excess amount over demand using the same lower of cost or net realizable value approach as that used to value the inventory.

Property and Equipment, net

Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets, generally three to five years. Leasehold improvements are amortized over the shorter of the estimated useful life of the improvements or the remaining lease term. Expenditures for repairs and maintenance, which do not extend the useful life of the property and equipment, are expensed as incurred. Upon retirement, the asset cost and related accumulated depreciation are relieved from the accompanying Consolidated Balance Sheets. Gains and losses associated with dispositions are reflected as a component of interest income and other income, net in the accompanying Consolidated Statements of Operations.

Impairment of Long-Lived Assets

The Company periodically assesses the impairment of long-lived assets and, if indicators of asset impairment exist, the Company assesses the recoverability of the affected long-lived assets by determining whether the carrying value of such assets can be recovered through an analysis of the undiscounted future expected operating cash flows. If impairment is indicated, the Company records the amount of such impairment for the excess of the carrying value of the asset over its estimated fair value. For example, if the Company is not successful in its commercialization of DSUVIA, and if approved, Zalviso, purchased equipment and manufacturing-related facility improvements the Company has made at its contract manufacturers could become impaired. The Company may determine that it is no longer probable that the Company will realize the future economic benefit associated with the costs of these assets through future manufacturing activities, and if so, the Company would record an impairment charge associated with these assets.

Contingent put option

The contingent put option associated with the Company’s Loan Agreement with Oxford is recorded as a liability. Changes in the fair value of the contingent put option are recognized as interest income and other income (expense), net in the Consolidated Statements of Operations. For further discussion, see Note 8 “Long-Term Debt”.

Leases

The Company follows the provisions of ASU No. 2016-02, Leases (Topic 842). At the inception of an arrangement, the Company determines whether the arrangement is, or contains, a lease based on the unique facts and circumstances present. Operating lease liabilities and their corresponding right-of-use assets are recorded based on the present value of lease payments over the expected lease term. The interest rate implicit in lease contracts is typically not readily determinable. As such, the Company utilizes its incremental borrowing rate, which is the rate incurred to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment. Certain adjustments to the right-of-use asset may be required for items such as initial direct costs paid or incentives received.

Lease expense is recognized over the expected term on a straight-line basis. Operating leases are recognized on the Consolidated Balance Sheets as operating lease right-of-use assets, operating lease liabilities current and operating lease liabilities non-current.

Revenue from Contracts with Customers

The Company follows the provisions of Accounting Standards Codification, or ASC, Topic 606, Revenue from Contracts with Customers. This guidance provides a unified model to determine how revenue is recognized. The Company recognizes revenue upon transfer of control of promised products or services to customers in an amount that reflects the consideration the Company expects to receive in exchange for those products or services. The Company sells its products primarily through wholesale and specialty distributors.

In determining the appropriate amount of revenue to be recognized as it fulfills its obligations under its agreements, the Company performs the following steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations, including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations based on estimated selling prices; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation.

Product sales revenue

The Company sells its product primarily through distributors. Revenues from product sales are recognized when distributors obtain control of the Company’s product, which occurs at a point in time, upon delivery to such distributors. These distributors subsequently resell the product to certified medically supervised healthcare settings. In addition to distribution agreements with these customers, the Company enters into arrangements with group purchasing organizations, or GPOs, and other certified medically supervised healthcare settings that provide for privately negotiated discounts with respect to the purchase of its products. For revenue recognition under bill-and-hold arrangements, wherein the customer agrees to buy product from the Company but requests delivery at a later date, the Company deems that control passes to the customer when the product is ready for delivery. The Company recognizes revenue under these types of arrangements when a signed agreement is in place, the transaction is billable, the customer has significant risk and rewards for the product and the ability to direct the asset, the product has been set aside specifically for the customer, and the product cannot be redirected to another customer. Revenue from product sales is recorded at the transaction price, net of estimates for variable consideration consisting of chargebacks, government rebates, returns, distribution fees, GPO fees and product returns. Variable consideration is recorded at the time product sales are recognized resulting in a reduction in product revenue. The amount of variable consideration that is included in the transaction price may be constrained and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. Variable consideration is estimated using the most-likely amount method, which is the single-most likely outcome under a contract and is typically at the stated contractual rate. Where appropriate, these estimates take into consideration a range of possible outcomes that are probability-weighted in accordance with the expected value method under ASC Topic 606 for relevant factors. These factors include current contractual and statutory requirements, specific known market events and trends, industry data, and/or forecasted customer buying and payment patterns. Actual amounts of consideration ultimately received may differ from the Company’s estimates. If actual results vary materially from the Company’s estimates, the Company will adjust these estimates, which will affect revenue from product sales and earnings in the period such estimates are adjusted. These estimates include:

Chargebacks – The Company’s customers subsequently resell its product to qualified healthcare providers. In addition to distribution agreements with customers, the Company enters into arrangements with qualified healthcare providers that provide discounts with respect to the purchase of its product. Chargebacks represent the estimated obligations resulting from contractual commitments to sell product to qualified healthcare providers at prices lower than the list prices charged to customers who directly purchase the product from the Company. Customers charge the Company for the difference between what they pay for the product and the ultimate selling price to the qualified healthcare providers. These reserves are established in the same period that the related revenue is recognized, resulting in a reduction of product revenue-related accrued liabilities on the Consolidated Balance Sheets. Chargeback amounts are determined at the time of resale to the qualified healthcare providers by customers, and the Company issues credits for such amounts generally within a few weeks of the customer's notification to the Company of the resale. Reserves for chargebacks consists of credits that the Company expects to issue for units that remain in the distribution channel inventories at each reporting period end that the Company expects will be sold to the qualified healthcare providers, and chargebacks for units that the Company’s customers have sold to the qualified healthcare providers, but for which credits have not been issued.

Government Rebates – The Company is subject to discount obligations under state Medicaid programs. The Company estimates its Medicaid rebates, and reserves are recorded in the same period the related product revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability that is included in accrued liabilities on the Consolidated Balance Sheet.

Returns – The Company allows its distributors to return product for credit 6 months prior to, and up to 12 months after, the product expiration date. As such, there may be a significant period of time between the time the product is shipped and the time the credit is issued on returned product.

Distribution Fees – Distribution fees include fees paid to certain customers for sales order management, data and distribution services. Distribution fees are recorded as a reduction of revenue in the period the related product revenue is recognized.

GPO Fees – The Company pays administrative fees to GPOs for services and access to data. These fees are based on contracted terms and are paid after the quarter in which the product was purchased by the GPOs’ members.

Trade Discounts and Allowances - The Company provides its customers with discounts which include early payment incentives that are explicitly stated in its contracts and are recorded as a reduction of revenue in the period the related product revenue is recognized.

The Company believes its estimated allowances for chargebacks, government rebates and product returns require a high degree of judgment and are subject to change based on its limited experience and certain quantitative and qualitative factors. The Company believes its estimated allowances for distribution fees, GPO fees and trade discounts and allowances do not require a high degree of judgment because the amounts are settled within a relatively short period of time. The Company will continue to assess its estimates of variable consideration as it accumulates additional historical data and will adjust these estimates accordingly. Changes in product revenue allowance estimates could materially affect the Company’s results of operations and financial position.

Contract and other collaboration revenue

The Company generates revenue from collaboration agreements. These agreements typically include payments for upfront signing or license fees, cost reimbursements for development and manufacturing services, milestone payments, product sales, and royalties on licensee’s future product sales. Product sales related revenue under these collaboration agreements is classified as product sales revenue, while other revenue generated from collaboration agreements is classified as contract and other collaboration revenue.

Performance Obligations

A performance obligation is a promise in a contract to transfer a distinct good or service to the customer and is the unit of account in ASC Topic 606. The Company’s performance obligations include delivering product to its distributors, commercialization license rights, development services, services associated with the regulatory approval process, joint steering committee services, demonstration devices, manufacturing services, material rights for discounts on manufacturing services, and product supply.

The Company has optional additional items in contracts, which are considered marketing offers and are accounted for as separate contracts when the customer elects such options. Arrangements that include a promise for future commercial product supply and optional research and development services at the customer’s or the Company’s discretion are generally considered as options. The Company assesses if these options provide a material right to the licensee and if so, such material rights are accounted for as separate performance obligations. If the Company is entitled to additional payments when the customer exercises these options, any additional payments are recorded in revenue when the customer obtains control of the goods or services.

Transaction Price

The Company has both fixed and variable consideration. Variable consideration for product revenue is described as Net product sales in the Consolidated Statements of Operations. For collaboration agreements, non-refundable upfront fees and product supply selling prices are considered fixed, while milestone payments are identified as variable consideration when determining the transaction price. Funding of research and development activities is considered variable until such costs are reimbursed at which point, they are considered fixed. The Company allocates the total transaction price to each performance obligation based on the relative estimated standalone selling prices of the promised goods or services for each performance obligation.

At the inception of each arrangement that includes milestone payments, the Company evaluates whether the milestones are considered probable of being achieved and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the value of the associated milestone (such as a regulatory submission by the Company) is included in the transaction price. Milestone payments that are not within the control of the Company, such as approvals from regulators, are not considered probable of being achieved until those approvals are received.

For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (a) when the related sales occur, or (b) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied).

Allocation of Consideration

As part of the accounting for collaboration arrangements, the Company must develop assumptions that require judgment to determine the stand-alone selling price of each performance obligation identified in the contract. Estimated selling prices for license rights and material rights for discounts on manufacturing services are calculated using an income approach model and can include the following key assumptions: the development timeline, sales forecasts, costs of product sales, commercialization expenses, discount rate, the time which the manufacturing services are expected to be performed, and probabilities of technical and regulatory success. For all other performance obligations, the Company uses a cost-plus margin approach.

Timing of Recognition

Significant management judgment is required to determine the level of effort required under collaboration arrangements and the period over which the Company expects to complete its performance obligations under the arrangement. The Company estimates the performance period or measure of progress at the inception of the arrangement and re-evaluates it each reporting period. This re-evaluation may shorten or lengthen the period over which revenue is recognized. Changes to these estimates are recorded on a cumulative catch-up basis. If the Company cannot reasonably estimate when its performance obligations either are completed or become inconsequential, then revenue recognition is deferred until the Company can reasonably make such estimates. Revenue is then recognized over the remaining estimated period of performance using the cumulative catch-up method. Revenue is recognized for products at a point in time when control of the product is transferred to the customer in an amount that reflects the consideration the Company expects to be entitled to in exchange for those product sales, which is typically once the product physically arrives at the customer, and for licenses of functional intellectual property at the point in time the customer can use and benefit from the license. For performance obligations that are services, revenue is recognized over time proportionate to the costs that the Company has incurred to perform the services using the cost-to-cost input method.

Cost of Goods Sold

Cost of goods sold for product revenue includes third party manufacturing costs, shipping and handling costs, and indirect overhead costs associated with production and distribution which are allocated to the appropriate cost pool and recognized when revenue is recognized. Indirect overhead costs in excess of normal capacity are recorded as period costs in the period incurred.

Under the Grünenthal Agreements, the Company sold Zalviso to Grünenthal at predetermined, contractual transfer prices that were less than the direct costs of manufacturing and recognized indirect costs as period costs where they were in excess of normal capacity and not recoverable on a lower of cost or net realizable value basis. Cost of goods sold for Zalviso shipped to Grünenthal included the inventory costs of API, third-party contract manufacturing costs, packaging and distribution costs, shipping, handling and storage costs, depreciation and costs of the employees involved with production.

Research and Development Expenses

Research and development costs are charged to expense when incurred. Research and development expenses include salaries, employee benefits, including stock-based compensation, consultant fees, laboratory supplies, costs associated with clinical trials and manufacturing, including contract research organization fees, other professional services and allocations of corporate costs. The Company reviews and accrues clinical trial expenses based on work performed, which relies on estimates of total costs incurred based on patient enrollment, completion of patient studies and other events.

Stock-Based Compensation

Compensation expense for all stock-based payment awards made to employees and directors, including employee stock options and restricted stock units related to the 2020 Equity Incentive Plan, or 2020 EIP, the 2011 Equity Incentive Plan, or 2011 EIP, and employee share purchases related to the Amended and Restated 2011 Employee Stock Purchase Plan, or ESPP, is based on estimated fair values at grant date. The Company determines the grant date fair value of the awards using the Black-Scholes option-pricing model and generally recognizes the fair value as stock-based compensation expense on a straight-line basis over the vesting period of the respective awards. The Company applies the graded-vesting attribution method to awards with market conditions that include graded-vesting features. Additionally, the Company uses the Monte Carlo Simulation model to evaluate the derived service period and fair value of awards with market conditions, including assumptions of historical volatility and risk-free interest rate commensurate with the vesting term.

The Black-Scholes option pricing model requires inputs such as expected term, expected volatility and risk-free interest rate. These inputs are subjective and generally require significant analysis and judgment to develop. The expected term, which represents the period of time that options granted are expected to be outstanding, is derived by analyzing the historical experience of similar awards, giving consideration to the contractual terms of the stock‑based awards, vesting schedules and expectations of future employee behavior. Expected volatilities are estimated using the historical stock price performance over the expected term of the option, which are adjusted as necessary for any other factors which may reasonably affect the volatility of AcelRx’s stock in the future. The risk‑free interest rate is based on the U.S. Treasury yield in effect at the time of the grant for the expected term of the award. The Company recognizes forfeitures when they occur and does not anticipate paying dividends in the near future.

Warrants Issued in Connection with Financings

The Company generally accounts for warrants issued in connection with debt and equity financings as a component of equity, unless the warrants include a conditional obligation to issue a variable number of shares or there is a deemed possibility that the Company may need to settle the warrants in cash. For warrants issued with a conditional obligation to issue a variable number of shares or the deemed possibility of a cash settlement, the Company records the fair value of the warrants as a liability at each balance sheet date and records changes in fair value in other (income) expense in the Consolidated Statements of Operations.

Restructuring Costs

The Company's restructuring costs consist of employee termination benefit costs. Liabilities for costs associated with the cost reduction plan are recognized when the liability is incurred and are measured at fair value. One-time termination benefits are expensed at the date the Company notifies the employee, unless the employee must provide future service, in which case the benefits are expensed ratably over the future service period.

On March 16, 2020, in connection with entering into the Co-Promotion Agreement, the Company initiated a reduction in headcount, designed to eliminate the overlap with the Tetraphase commercial team in order to more efficiently commercialize DSUVIA alongside the Tetraphase commercial team and reduce operating expenses. The Company eliminated 30 positions, primarily within the commercial organization. For the year ended December 31, 2020, the Company incurred and paid $0.5 million in employee termination benefits related to this restructuring. The headcount reduction was completed in the first quarter of 2020. There were no such restructuring costs for the year ended December 31, 2021.

Non-Cash Interest Income (Expense) on Liability Related to Sale of Future Royalties

In September 2015, the Company sold certain royalty and milestone payment rights from the sales of Zalviso in the European Union by Grünenthal to PDL for gross proceeds of $65.0 million. Grünenthal terminated the Grünenthal Agreements effective November 13, 2020. The terms of the Grünenthal Agreements were extended to May 2021 to enable Grünenthal to sell down its Zalviso inventory. The rights to market and sell Zalviso in the Territory reverted back to the Company in May 2021.

Under the Royalty Monetization, the Company has a continuing obligation to use commercially reasonable efforts to negotiate a replacement license agreement, or New Arrangement. Under the relevant accounting guidance, because of the Company’s significant continuing involvement, the Royalty Monetization is accounted for as a liability that is being amortized using the effective interest method over the life of the arrangement. In order to determine the amortization of the liability, the Company is required to estimate the total amount of future royalty and milestone payments to be received by ARPI LLC and payments made to PDL, up to a capped amount of $195.0 million, over the life of the arrangement. The aggregate future estimated royalty and milestone payments (subject to the capped amount), less the $61.2 million of net proceeds the Company received, are amortized as interest expense over the life of the liability. Consequently, the Company imputes interest on the unamortized portion of the liability and records interest expense, or interest income, as these estimates are updated.

There are a number of factors that could materially affect the amount and timing of royalty and milestone payments from Zalviso in Europe, most of which are not within the Company’s control. Such factors include, but are not limited to, the success of any future sales and promotion of Zalviso under any New Arrangement, if achieved; changing standards of care; the introduction of competing products; manufacturing or other delays; intellectual property matters; adverse events that result in governmental health authority imposed restrictions on the use of Zalviso; significant changes in foreign exchange rates as the royalties remitted to ARPI LLC are made in U.S. dollars; and other events or circumstances that could result in reduced royalty payments from European sales of Zalviso, all of which may result in a reduction of non-cash royalty revenues and the non-cash interest expense over the life of the Royalty Monetization. Conversely, if sales of Zalviso in Europe are greater than expected, the non-cash royalty revenues and the non-cash interest expense recorded by the Company would be greater over the term of the Royalty Monetization. The Company periodically assesses the expected royalty and milestone payments using a combination of historical results, internal projections and forecasts from external sources. To the extent such payments are greater or less than the Company’s initial estimates or the timing of such payments is materially different than its original estimates, the Company will prospectively adjust the amortization of the liability and the effective interest rate. Because estimated sales forecasts and payments may vary over the life of the Royalty Monetization, the Company may be required to recognize interest income as the imputed interest rate is adjusted prospectively to reflect the revised effective interest rate over the term of the Royalty Monetization.

The Company records non-cash royalty revenues and non-cash interest income (expense), net, within its Consolidated Statements of Operations over the term of the Royalty Monetization.

When the expected payments under the Royalty Monetization are lower than the gross proceeds of $65.0 million received, the Company defers recognition of any probable contingent gain until the Royalty Monetization liability expires.

Comprehensive Loss

Comprehensive loss is comprised of net loss and other comprehensive income (loss) and is disclosed in the Consolidated Statements of Operations. For the Company, other comprehensive income (loss) consists of changes in unrealized gains and losses on the Company’s investments.

Income Taxes

Deferred tax assets and liabilities are measured based on differences between the financial reporting and tax basis of assets and liabilities using enacted rates and laws that are expected to be in effect when the differences are expected to reverse. The Company records a valuation allowance for the full amount of deferred assets, which would otherwise be recorded for tax benefits relating to operating loss and tax credit carryforwards, as realization of such deferred tax assets cannot be determined to be more likely than not.

Net Loss per Share of Common Stock

The Company’s basic net loss per share of common stock is calculated by dividing the net loss by the weighted average number of shares of common stock outstanding for the period. The diluted net loss per share of common stock is computed by giving effect to all potential common stock equivalents outstanding for the period determined using the treasury stock method. For purposes of this calculation, convertible preferred stock, options to purchase common stock, restricted stock subject to repurchase, restricted stock units, warrants to purchase convertible preferred stock and warrants to purchase common stock were considered to be common stock equivalents. In periods with a reported net loss, such common stock equivalents are excluded from the calculation of diluted net loss per share of common stock if their effect is antidilutive. For additional information regarding the net loss per share, see Note 15 “Net Loss per Share of Common Stock”.

Recently Adopted Accounting Standards

In December 2019, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2019-12, “Simplifying the Accounting for Income Taxes”. ASU 2019-12 eliminates certain exceptions related to the approach for intra-period tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. It also clarifies and simplifies other aspects of the accounting for income taxes. ASU 2019-12 is effective for fiscal years beginning after December 15, 2020, and interim periods within those fiscal years. The Company adopted ASU 2019-12 on January 1, 2021, which did not have a material impact on the Company’s Consolidated Financial Statements.

In August 2020, the FASB issued ASU 2020-06, “Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity's Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity's Own Equity”. The standard simplifies accounting for convertible instruments by removing major separation models required under current GAAP. Consequently, more convertible debt instruments will be reported as a single liability instrument with no separate accounting for embedded conversion features. ASU 2020-06 removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception, which will permit more equity contracts to qualify for it. The standard also simplifies the diluted net income per share calculation in certain areas. ASU 2020-06 is effective for fiscal years beginning after December 15, 2023, and interim periods within those fiscal years for smaller reporting companies, with early adoption permitted. The Company early adopted ASU 2020-06 on January 1, 2021, which did not have a material impact on the Company’s Consolidated Financial Statements on the date of adoption.

Recently Issued Accounting Pronouncements

In June 2016, the FASB issued ASU 2016-13, “Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments,” or ASU 2016-13. ASU 2016-13 replaces the incurred loss impairment model in current GAAP with a model that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to determine credit loss estimates. ASU 2016-13 is effective for the Company beginning January 1, 2023, with early adoption allowed beginning January 1, 2020. In May 2019, the FASB issued ASU 2019-05, “Financial Instruments – Credit Losses,” or ASU 2019-05, to allow entities to irrevocably elect the fair value option for certain financial assets previously measured at amortized cost upon adoption of the new credit losses standard. The new effective dates and transition align with those of ASU 2016-13. Management is currently assessing the date of adoption and the impact ASU 2016-13 and ASU 2019-05 will have on the Company, but it does not anticipate adoption of these new standards to have a material impact on the Company’s financial position, results of operations or cash flows.

In March 2020, the FASB issued ASU 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting,” which provides elective amendments for entities that have contracts, hedging relationships and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. These amendments are effective immediately and may be applied prospectively to contract modifications made and hedging relationships entered into or evaluated on or before December 31, 2022. In January 2021, the FASB issued ASU 2021-01, “Reference Rate Reform (Topic 848),” to expand and clarify the scope of Topic 848 to include derivative instruments on discounting transactions. The amendments in this ASU are effective in the same timeframe as ASU 2020-04. The Company is currently evaluating the impact this guidance will have on its Consolidated Financial Statements.

Note 2 - Investments and Fair Value Measurement

12 Months Ended

Dec. 31, 2021

Investments and Fair Value Measurement Disclosure [Text Block]

2. Investments and Fair Value Measurement

Investments

The Company classifies its marketable securities as available-for-sale and records its investments at fair value. Available-for-sale securities are carried at estimated fair value based on quoted market prices or observable market inputs of almost identical assets, with the unrealized holding gains and losses included in accumulated other comprehensive income (loss). Marketable securities which have maturities beyond one year as of the end of the reporting period are classified as non-current.

The table below summarizes the Company’s cash, cash equivalents and investments (in thousands):

	As of December 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Cash and cash equivalents:
Cash	$	1,443	$	—	$	—	$	1,443
Money market funds		2,822		—		—		2,822
Commercial paper		8,398		—		—		8,398
Total cash and cash equivalents		12,663		—		—		12,663

Short-term investments:
Commercial paper		29,504		—		—		29,504
Corporate debt securities		9,463		—		—		9,463
Total short-term investments		38,967		—		—		38,967
Total cash, cash equivalents and short-term investments	$	51,630	$	—	$	—	$	51,630

	As of December 31, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Cash and cash equivalents:
Cash	$	5,181	$	—	$	—	$	5,181
Money market funds		3,996		—		—		3,996
Commercial paper		18,097		—		—		18,097
Total cash and cash equivalents		27,274		—		—		27,274

Short-term investments:
U.S. government agency securities		5,818		—		—		5,818
Commercial paper		9,794		—		—		9,794
Total short-term investments		15,612		—		—		15,612
Total cash, cash equivalents and short-term investments	$	42,886	$	—	$	—	$	42,886

None of the available-for-sale securities held by the Company had material unrealized losses and there were no realized losses for the years ended December 31, 2021 and 2020. There were no other-than-temporary impairments for these securities as of December 31, 2021 or 2020. No gross realized gains or losses were recognized on the available-for-sale securities and, accordingly, there were no amounts reclassified out of accumulated other comprehensive income (loss) to earnings during the years ended December 31, 2021 and 2020.

As of December 31, 2021 and 2020, the contractual maturity of all investments held was less than one year.

Fair Value Measurement

The Company’s financial instruments consist of Level I and II assets and Level III liabilities. Money market funds are highly liquid investments and are actively traded. The pricing information on these investment instruments are readily available and can be independently validated as of the measurement date. This approach results in the classification of these securities as Level 1 of the fair value hierarchy. For Level II instruments, the Company estimates fair value by utilizing third party pricing services in developing fair value measurements where fair value is based on valuation methodologies such as models using observable market inputs, including benchmark yields, reported trades, broker/dealer quotes, bids, offers and other reference data. Such Level II instruments typically include U.S. treasury, U.S. government agency securities and commercial paper. As of December 31, 2021, and December 31, 2020, the Company held, in addition to Level II assets, a contingent put option liability associated with the Loan Agreement with Oxford. See Note 8 “Long-Term Debt” for further description. The Company’s estimate of fair value of the contingent put option liability was determined by using a risk-neutral valuation model, wherein the fair value of the underlying debt facility is estimated both with and without the presence of the default provisions, holding all other assumptions constant. The resulting difference between the two estimated fair values is the estimated fair value of the default provisions, or the contingent put option, which is included under other long-term liabilities on the Consolidated Balance Sheets. Changes to the estimated fair value of this liability is recorded in interest income and other income (expense), net in the Consolidated Statements of Operations. The fair value of the underlying debt facility is estimated by calculating the expected cash flows in consideration of an estimated probability of default and expected recovery rate in default and discounting such cash flows back to the reporting date using a risk-free rate.

The following table sets forth the fair value of the Company’s financial assets and liabilities by level within the fair value hierarchy (in thousands):

	As of December 31, 2021
	Fair Value		Level I		Level II		Level III
Assets
Money market funds	$	2,822	$	2,822	$	—	$	—
Commercial paper		37,902		—		37,902		—
Corporate debt securities		9,463		—		9,463		—
Total assets measured at fair value	$	50,187	$	2,822	$	47,365	$	—

Liabilities
Contingent put option liability	$	81	$	—	$	—	$	81
Total liabilities measured at fair value	$	81	$	—	$	—	$	81

	As of December 31, 2020
	Fair Value		Level I		Level II		Level III
Assets
Money market funds	$	3,996	$	3,996	$	—	$	—
U.S. government agency securities		5,818		—		5,818		—
Commercial paper		27,891		—		27,891		—
Total assets measured at fair value	$	37,705	$	3,996	$	33,709	$	—

Liabilities
Contingent put option liability	$	246	$	—	$	—	$	246
Total liabilities measured at fair value	$	246	$	—	$	—	$	246

The following table sets forth a summary of the changes in the fair value of the Company’s Level III financial liabilities for the years ended December 31, 2021 and 2020 (in thousands):

	Year Ended December 31, 2021
Fair value—beginning of period	$	246
Change in fair value of contingent put option associated with the Loan Agreement		(165	)
Fair value—end of period	$	81

	Year Ended December 31, 2020
Fair value—beginning of period	$	437
Change in fair value of contingent put option associated with the Loan Agreement		(191	)
Fair value—end of period	$	246

Note 3 - Inventories, Net

12 Months Ended

Dec. 31, 2021

Inventory Disclosure [Text Block]

3. Inventories, net

Inventories consist of finished goods, raw materials and work in process and are stated at the lower of cost or net realizable value and consist of the following (in thousands):

	As of December 31,
	2021		2020
Raw materials	$	722	$	257
Work-in-process		159		30
Finished goods		230		1,339
Inventories	$	1,111	$	1,626

During the year ended December 31, 2021, the Company recorded inventory impairment charges of approximately $0.8 million, primarily as a result of DSUVIA inventory that may expire before being sold. During the year ended December 31, 2020, the Company recorded inventory impairment charges of approximately $0.7 million, of which $0.3 million related to the termination of the Amended Agreements, while $0.4 million related to DSUVIA inventory, primarily inventory that may expire before being sold.

Note 4 - Property and Equipment, Net

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment Disclosure [Text Block]

4. Property and Equipment, net

Property and equipment, net consist of the following (in thousands):

	As of December 31,
	2021			2020
Laboratory equipment	$	4,406		$	4,406
Leasehold improvements		5,838			4,616
Computer equipment and software		1,589			1,724
Construction in process		13,805			14,101
Tooling		826			1,109
Furniture and fixtures		250			292
		26,714			26,248
Less accumulated depreciation and amortization		(10,786	)		(10,589	)
Property and equipment, net	$	15,928		$	15,659

Depreciation and amortization expense was $1.1 million for each of the years ended December 31, 2021 and 2020, respectively.

Note 5 - In-license Agreement

12 Months Ended

Dec. 31, 2021

In-license Agreement [Text Block]

5. In-License Agreement

On July 14, 2021, the Company entered into a License and Commercialization Agreement, or the PFS Agreement, with Aguettant pursuant to which the Company obtained the exclusive right to develop and, subject to FDA approval, commercialize in the United States (i) an ephedrine pre-filled syringe containing 10 ml of a solution of 3 mg/ml ephedrine hydrochloride for injection, and (ii) a phenylephrine pre-filled syringe containing 10 ml of a solution of 50 mcg/ml phenylephrine hydrochloride for injection. Aguettant will supply the Company with the products for use in commercialization, if they are approved in the U.S.

The PFS Agreement has an initial term of ten (10) marketing years, with the first marketing year ending on December 31 of the calendar year after the first launch of a product (or December 31 of the same calendar year if the first launch of a product occurs between January 1 and April 30 of a calendar year). The term will automatically renew for successive five marketing year periods unless a party notifies the other party of its intention not to renew at least six (6) months prior to the expiration of the then-current term.

Aguettant is entitled to receive up to $24.0 million in sales-based milestone payments. The Company will purchase each product from Aguettant at an agreed price, or the PFS Purchase Price, subject to adjustment. The Company will also make revenue share payments that, combined with the PFS Purchase Price, will range from 40% to 45% of net sales in the United States.

The Company and Aguettant will agree on minimum sales obligations twelve (12) months prior to the launch of each product.

The Company has the right to grant sublicenses to its affiliates or, with the prior approval of Aguettant, third parties, subject to certain limitations.

As of December 31, 2021, there have been no payments by the Company to Aguettant under the PFS Agreement.

Note 6 - Out-license Agreements

12 Months Ended

Dec. 31, 2021

Out-license Agreement [Text Block]

6. Out-license Agreements

DZUVEO

On July 14, 2021, the Company entered into a License and Commercialization Agreement, or the DZUVEO Agreement, with Aguettant, pursuant to which Aguettant obtained the exclusive right to develop and commercialize DZUVEO in the European Union, Norway, Iceland, Liechtenstein, Andorra, Vatican City, Monaco, Switzerland and the United Kingdom, or the DZUVEO Territory, for the management of acute moderate to severe pain in adults in medically monitored settings. The Company will supply Aguettant with product.

The DZUVEO Agreement has an initial term of ten (10) marketing years, with the first marketing year ending on December 31 of the calendar year after the launch of DZUVEO (or December 31, 2022, if the launch occurs between January 1, 2022 and April 30, 2022). The term will automatically renew for successive five marketing year periods unless a party notifies the other party of its intention not to renew at least six (6) months prior to the expiration of the then-current term. The DZUVEO Agreement may be terminated for cause by either party based on uncured material breach by the other party, insolvency of the other party, or force majeure event. Upon early termination, all ongoing activities under the agreement and all rights and commercialization licenses and sublicenses with respect to DZUVEO will terminate. Additionally, if terminated early by either party, any accrued liability at the time of such termination will not be released.

The Company is entitled to receive up to €47.0 million in a combination of up-front and sales-based milestone payments, of which the Company received €2.5 million, or approximately $2.9 million, in the third quarter of 2021, for which it recognized revenue of $1.7 million in the third quarter of 2021. Aguettant will purchase product from the Company at an agreed price, or the DZUVEO Purchase Price, subject to adjustment. Aguettant will also make revenue share payments that, combined with the DZUVEO Purchase Price, range from 35% to 45% of net sales in the DZUVEO Territory.

Beginning in the third marketing year, the parties will establish binding annual minimums for purchase orders to be submitted by Aguettant. Aguettant has the right to grant sublicenses to its affiliates or, with the prior approval of the Company, third parties, subject to certain limitations.

The DZUVEO Agreement also provides Aguettant with a right of first negotiation for eighteen (18) months before the Company can enter into a collaboration regarding Zalviso in Europe.

Zalviso

Amended License Agreement

Under the Amended License Agreement with Grünenthal, the Company was eligible to receive approximately $194.5 million in additional milestone payments, based upon successful regulatory and product development efforts ($28.5 million) and net sales target achievements ($166.0 million). A portion of the tiered royalty payments earned were paid to PDL in connection with the Royalty Monetization. For additional information on the Royalty Monetization with PDL, see Note 10 “Liability Related to Sale of Future Royalties”. On August 31, 2020, PDL announced it sold its royalty interest for Zalviso to SWK Funding, LLC.

Amended MSA

Under the terms of the Amended MSA with Grünenthal, the Company manufactured and supplied the Product for use in the Field for the Territory exclusively for Grünenthal. The Product was supplied at prices approximating the Company’s manufacturing cost, subject to certain caps, as defined in the MSA Amendment.

The Grünenthal Agreements entitled the Company to receive additional payments upon the achievement of certain development milestones which related to post approval product enhancements, expanded market opportunities and manufacturing efficiencies for Zalviso and required future research, development and regulatory activities. These payments were excluded from the transaction price as they were considered payments for optional additional services elected by Grünenthal.

The Grünenthal Agreements also included milestone payments related to specified net sales targets, totaling $166.0 million. These payments were considered sales-based license royalties under ASC Topic 606 and would have been recognized apart from the other contract consideration when the related sales occurred. These net sales targets were not achieved prior to the termination of the Grünenthal Agreements.

Note 7 - Revenue From Contracts With Customers

12 Months Ended

Dec. 31, 2021

Revenue from Contract with Customer [Text Block]

7. Revenue from Contracts with Customers

The following table summarizes revenue from contracts with customers for the years ended December 31, 2021 and 2020 into categories that depict how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors (in thousands):

	December 31,
	2021		2020
Product sales:
DSUVIA	$	735	$	1,409
Zalviso		270		1,112
Total product sales		1,005		2,521
Contract and other collaboration:
License revenue		1,696		—
Non-cash royalty revenue related to Royalty Monetization (See Note 10)		83		242
Royalty revenue		28		81
Other revenue		6		2,572
Total revenues from contract and other collaboration		1,813		2,895
Total revenue	$	2,818	$	5,416

For additional detail on the Company’s accounting policy regarding revenue recognition, refer to Note 1 “Organization and Summary of Significant Accounting Policies - Revenue from Contracts with Customers.”

Product Sales

The Company’s commercial launch of DSUVIA in the United States occurred in the first quarter of 2019. Zalviso was sold in Europe by Grünenthal through May 12, 2021. DZUVEO sales in Europe by the Company’s collaboration partner, Aguettant, have not commenced as of December 31, 2021.

Contract and Other Collaboration

Contract and other collaboration revenue includes revenue under the Grünenthal Agreements related to research and development services, non-cash royalty revenue related to the Royalty Monetization and royalty revenue for sales of Zalviso in Europe and license revenue recognized under the DZUVEO Agreement.

The Company concluded that Aguettant is a customer and therefore revenue recognition for the DZUVEO Agreement in Europe should be accounted for in accordance with FASB Accounting Standards Codification, or ASC, Topic 606, “Revenue from Contracts with Customers”, because the Company granted to Aguettant licenses and will provide the supply of product, as defined below, all of which are outputs of the Company’s ongoing activities, in exchange for consideration.

The Company identified the following promises under the DZUVEO Agreement at inception, namely: (a) granting of the licenses, (b) manufacturing services inclusive of quality control testing and stability testing which are options in the initial arrangement, and (c) a material right associated with the discounted price for future optional orders of DZUVEO commercial product supply.

The licenses are considered to be functional intellectual property. The Company determined that the licenses are capable of being distinct because Aguettant can benefit from the license on its own by commercializing the underlying product using its own resources. The Company manufacturing services are not highly specialized in nature and can be performed by third party contract manufacturing organizations. There are no binding commitments for manufacturing purchase orders at inception of the arrangement. Therefore, the manufacturing services are considered to be an option and not a performance obligation in the initial arrangement. However, the Company has determined that the discounted price per unit on future optional product orders constitutes a material right and is a performance obligation. The right to purchase at a discount is capable of being used by the customer on a standalone basis, because this relates to future product purchases and occur after the licenses’ performance obligations are transferred.

The Company evaluated if there is an interdependence between the performance obligations and determined that the licenses are a combined solution and the predominant performance obligation. The material right is separately identifiable in the context of the contract and is not modified by, and does not modify, the license performance obligation and is not highly interdependent or interrelated with the material right performance obligations in the contract.

The transaction price at the inception of the DZUVEO Agreement consisted of the upfront fee of €2.5 million, or approximately $2.9 million. The variable consideration related to product supply and reimbursables has been constrained as of December 31, 2021 as there has been no forecast provided by Aguettant. The Company will re-evaluate the transaction price each reporting period and as uncertain events are resolved or other changes in circumstances occur.

The Company determined that the $52.2 million sales-based milestone payments and revenue share payments were probable of significant revenue reversal, as their achievement was highly dependent on factors outside the Company’s control. As a result, these payments were fully constrained and were not included in the transaction price. Any variable consideration related to sales-based milestones (including royalties) will be recognized when the related sales occur, as they were determined to relate predominantly to the licenses granted to Aguettant and the optional manufacturing services provided by the Company.

The transaction price is allocated to the performance obligations based on relative standalone selling price which were determined for the licenses using the adjusted market approach, and for the manufacturing services and the material right associated with discounted DZUVEO product supply using the cost-plus reasonable margin approach. Variable consideration is allocated to the specific performance obligations to which it relates.

For revenue recognition purposes, the Company determined that the duration of the contract began on the effective date in July 2021 and ends after an initial term of 10 marketing years, unless it automatically renews for a successive five marketing years. The Company also analyzed the impact if Aguettant terminated the agreement prior to the end of the term and determined, considering both quantitative and qualitative factors, that there were substantive non-monetary penalties to Aguettant for doing so.

Revenue for the granting of the licenses was recognized on the effective date of the DZUVEO Agreement at the point in time that the licenses are effective. The manufacturing services inclusive of quality control testing and stability testing will be recognized at a point in time when, or as, the Company transfers the associated promised goods and services to Aguettant. The material right for the discounted price per unit on future optional orders will be recognized over time with the measure of progress being straight-line over the period in which the Company stands ready to provide the discounted price per unit on the manufacturing services.

For the year ended December 31, 2021, the Company recorded $1.7 million in contract and other collaboration revenue as a result of satisfying its licenses performance obligation by transferring the license rights to Aguettant.

Contract Liabilities

A contract liability of $1.2 million was recorded on the Consolidated Balance Sheets as deferred revenue as of December 31, 2021, $0.1 million of which represented the current portion, for the portion of the upfront fee received under the DZUVEO Agreement allocated to the material right for discounted price on future optional product supply which has not yet been satisfied. The material right contract liability will be recognized over the period the discount on future product supply is made available. There was no contract asset as of December 31, 2021 associated with the DZUVEO Agreement.

As of December 31, 2021, deferred contract acquisition costs were negligible and deferred contract acquisition costs amortized during the year ended December 31, 2021 were $0.3 million.

The following table presents changes in the Company’s contract liability for the years ended December 31, 2021 and 2020 (in thousands):

Balance at January 1, 2020	$	3,244
Deductions for performance obligations satisfied:
In current period		( 623	)
In prior periods⁽¹⁾		(2,572	)
Balance at December 31, 2020	$	49
Additions⁽²⁾		1,237
Deductions for performance obligations satisfied:
In current period		(49	)
Balance at December 31, 2021	$	1,237

⁽¹⁾ In May 2020, upon notification of early termination by Grünenthal, the Company recognized approximately $2.6 million of deferred revenue under the Grünenthal Agreements.

⁽²⁾Deferred revenue under the DZUVEO Agreement with Aguettant.

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

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Note 8 - Long-term Debt

12 Months Ended

Dec. 31, 2021

Long-term Debt [Text Block]

8. Long-Term Debt

Loan Agreement with Oxford

On May 30, 2019, the Company entered into the Loan Agreement with Oxford as the Lender. Under the Loan Agreement, the Lender made a term loan to the Company in an aggregate principal amount of $25.0 million, or the Loan, which was funded on May 30, 2019. The Company used approximately $8.9 million of the proceeds from the Loan to repay its outstanding obligations under its prior debt agreement. After deducting all loan initiation costs and outstanding interest on the prior debt agreement, the Company received $15.9 million in net proceeds.

The interest rate is calculated at a rate equal to the sum of (a) the greater of (i) the 30-day U.S. LIBOR rate reported in The Wall Street Journal on the last business day of the month that immediately precedes the month in which the interest will accrue and (ii) 2.50%, plus (b) 6.75%. On July 27, 2017, the Financial Conduct Authority, or FCA, in the U.K. announced that it would phase out LIBOR as a benchmark by the end of 2021. It is unclear whether new methods of calculating LIBOR will be established such that it continues to exist after 2021 or if LIBOR will be replaced with an alternative reference rate; however, the Company does not believe such changes would have a material adverse effect on its financing costs. Payments on the Loan were interest-only until July 1, 2020 followed by equal principal payments and monthly accrued interest payments through the scheduled maturity date of June 1, 2023. The Company’s obligations under the Loan Agreement are secured by a security interest in all the assets of the Company, other than the Company’s intellectual property which is subject to a negative pledge.

The Company may prepay the Loan at any time. If the Loan is paid prior to the maturity date, the Company will pay the Lender a prepayment charge, based on a percentage of the then outstanding principal balance, equal to 1%. Upon voluntary or mandatory prepayment, in addition to the prepayment charge, the Company is required to pay the EOT Fee, Lender’s expenses and all outstanding principal and accrued interest through the prepayment date.

The Loan Agreement includes customary representations and covenants that, subject to exceptions, will restrict the Company’s ability to do the following things: declare dividends or redeem or repurchase equity interests; incur additional liens; make loans and investments; incur additional indebtedness; engage in mergers, acquisitions, and asset sales; transact with affiliates; undergo a change in control; add or change business locations; and engage in businesses that are not related to its existing business. The Loan Agreement requires that the Company always maintain unrestricted cash of not less than $5.0 million in accounts subject to control agreements in favor of Lender, tested monthly as of the last day of the month.

The Loan Agreement also includes standard events of default, including payment defaults, breaches of covenants following any applicable cure period, a material impairment in the perfection or priority of the Lender’s security interest or in the value of the collateral, a material adverse change in business, operations or the prospect of repayment, events relating to bankruptcy or insolvency. The Loan also contains a cross default provision, under which if a third party (under any agreement) has the right to accelerate indebtedness greater than $250,000, the Loan would also be considered in default. In addition, the Loan defines events which negatively impact government approvals, judgments in excess of $500,000 and the delisting of the Company’s shares of common stock on the Nasdaq Global Market, or Nasdaq, as events of default. Upon the occurrence of an event of default, a default interest rate of an additional 5% may be applied to the outstanding loan balances, and the Lender may declare all outstanding obligations immediately due and payable and take such other actions as set forth in the Loan Agreement. Acceleration would result in the payment of any applicable prepayment charges and application of the default interest rate to the outstanding balance until payment is made in full. The Company bifurcated a compound derivative liability related to a contingent interest feature and acceleration upon default provision (contingent put option) provided to the Lender. The bifurcated embedded derivative must be valued and separately accounted for in the Company’s Consolidated Financial Statements. The contingent put option liability is classified as a component of other long-term liabilities. As of December 31, 2021, the estimated fair value of the contingent put option liability was $0.1 million which was determined by using a risk-neutral valuation model, wherein the fair value of the underlying debt facility is estimated, both with and without the presence of the default provisions, holding all other assumptions constant. See Note 2 “Investments and Fair Value Measurement” for further description.

The outstanding balance due under the Loan Agreement was $13.3 million and $21.0 million at December 31, 2021 and 2020, respectively. Interest expense related to the Loan Agreement was $2.2 million, of which $0.7 million represented amortization of the debt discount, and $3.2 million, $0.9 million of which represented amortization of the debt discount, for the years ended December 31, 2021 and 2020, respectively, and the effective interest rate was 13.15% in both periods.

Non-Interest Bearing Payments for the Construction of Leasehold Improvements

In August 2019, the Company entered into a Site Readiness Agreement, or SRA, with a potential Contract Manufacturing Organization, or CMO, in contemplation of entering into a commercial supply agreement for its product DSUVIA® at a future date. Under the SRA, the Company is building out a suite within the CMO’s production facility. If additional equipment and facility modifications are required to meet the Company’s product needs, the Company may be required to contribute to the cost of such additional equipment and facility modifications. The Company has determined that it is the owner of the leasehold improvements related to the build-out which will be paid for in four annual installments of $0.5 million through July 2022. As of December 31, 2021 and 2020, the accrued balance under the SRA is $0.5 million and $0.8 million, respectively, and $1.7 million of these leasehold improvements have been capitalized. The effective interest rate related to the payments at December 31, 2021 and 2020 was 14.35%. The leasehold improvements are recorded as property and equipment, net, in the Consolidated Balance Sheets.

Future Payments on Long-Term Debt

The following table summarizes the outstanding future payments associated with the Company’s long-term debt as of December 31, 2021 (in thousands):

2022	$	9,647
2023		5,530
Total payments		15,177
Less amount representing interest		(927	)
Notes payable, gross		14,250
Less: Unamortized portion of EOT Fee		(200	)
Less: Unamortized discount on notes payable		(247	)
Long-term debt		13,803
Less current portion		(8,796	)
Long-term debt, net of current portion	$	5,007

Note 9 - Leases

12 Months Ended

Dec. 31, 2021

Lessee, Operating Leases [Text Block]

9. Leases

Office Lease

The Company leased office and laboratory space for its former corporate headquarters, located at 301 – 351 Galveston Drive, Redwood City, California, and entered into an agreement to sublease approximately 12,106 square feet of this office and laboratory space.

On March 26, 2021, the Company entered into a Lease Termination Agreement with its landlord and a Sublease Termination Agreement with its sublessee, to terminate the lease and sublease agreements at its former corporate headquarters. The termination of both the lease and sublease was effective on April 30, 2021. As of the date of the Lease Termination Agreement, the Company remeasured its lease liability and recorded a gain of $0.5 million upon derecognition of the lease liability and right of use asset for the master lease, which was included in operating expenses for the year ended December 31, 2021. In connection with the Sublease Termination, the remaining deferred costs of $0.3 million were fully amortized through April 30, 2021, the effective date of the Sublease Termination, and included in operating expenses for the year ended December 31, 2021.

On March 26, 2021, the Company entered into a Sublease Agreement to sublet space for its new corporate headquarters, located at 25821 Industrial Boulevard, Hayward, California. The Sublease Agreement commencement date was April 1, 2021. The Sublease Agreement is for a period of two years and three months with monthly rental payments of $17,000, including one month of abated rent. On the lease commencement date, the Company recognized an operating lease right-of-use asset in the amount of $0.4 million.

Contract Manufacturing Leases

On December 12, 2012, the Company entered into an agreement for commercial supply manufacturing services related to the Company’s Zalviso drug product with a contract manufacturing organization. The initial term of the agreement was through December 31, 2017, which term automatically renews in two-year increments unless earlier terminated by either party by giving eighteen months’ notice. Commencing in 2013, the Company is required to make overhead fee payments each year of $0.2 million, prorated based on aggregate revenues. The Company has determined that this fee is an in-substance fixed lease payment as it represents the minimum annual payment under the contract. The Company concluded that this agreement contains an embedded lease as the clean rooms have been built specifically for production of the Company’s product and their use is effectively controlled by the Company as it has priority over the space during the term of the agreement. The Company accounts for the agreement as an operating lease and has evaluated the non-cancelable term to be through the binding commitment date of June 30, 2023.

On April 21, 2021, the Company entered into a Commercial Supply Agreement, or the CSA, with Catalent Pharma Solutions, LLC, or Catalent, effective March 31, 2021, under which Catalent provides certain services to the Company in connection with the processing and packaging of a packaged single dose applicator containing the sublingual tablet 30 mcg sufentanil dosage form contained in the pharmaceutical product, DSUVIA (sufentanil), intended for commercialization.

The term of the CSA is for a period of five years from the first date upon which the FDA approves Catalent as a manufacturer of DSUVIA in the United States, or the Commencement Date. The term shall automatically be extended for successive two-year periods, unless and until one party gives the other party at least 24 months’ prior written notice of its desire to terminate as of the end of the then-current term.

The Company will pay Catalent an annual fee of $1.0 million beginning January 1, 2022. Pursuant to the CSA, the Company will purchase each 10-pack carton of DSUVIA from Catalent at an agreed price through December 31, 2022, and pay other fees set forth in the CSA. All pricing and fees, with the exception of raw materials, may be adjusted on an annual basis, effective on January 1 of each calendar year, beginning with January 1, 2023, subject to certain limitations. Price increases for raw materials will be passed through to the Company.

The Company has determined that the fixed fees in the CSA are in-substance lease payments. The Company concluded that this agreement contains an embedded lease as the clean rooms have been built specifically for production of the Company’s product and their use is effectively controlled by the Company as it has sole use over the space during the term of the agreement. The Company accounts for the agreement as an operating lease and has evaluated the non-cancelable lease term to be through the binding commitment date of May 15, 2027.

The components of lease expense are presented in the following table (in thousands):

	Year ended December 31, 2021			Year ended December 31, 2020
Operating lease costs	$	1,467		$	1,360
Gain on derecognition of operating lease		(522	)		—
Sublease income		(199	)		(598	)
Loss on termination of sublease		331			—
Net lease costs	$	1,077		$	762

The weighted average remaining lease term and discount rate related to the operating leases are presented in the following table:

	December 31,			December 31,
	2021			2020
Weighted-average remaining lease term – operating leases (in years)	4.97			3.1
Weighted-average remaining discount rate – operating leases (in years)		12.8	%		11.7	%

Maturities of lease liabilities as of December 31, 2021 are presented in the following table (in thousands):

Year:
2022	$	1,608
2023		1,244
2024		1,040
2025		1,040
2026		1,040
Thereafter		415
Total future minimum lease payments		6,387
Less imputed interest		(1,569	)
Total	$	4,818

Reported as:

Operating lease liabilities	$	4,818
Operating lease liabilities, current portion		(1,068	)
Operating lease liabilities, net of current portion	$	3,750

Note 10 - Liability Related to Sale of Future Royalties

12 Months Ended

Dec. 31, 2021

10. Liability Related to Sale of Future Royalties

On September 18, 2015, the Company entered into the Royalty Monetization with PDL for which it received gross proceeds of $65.0 million. Under the Royalty Monetization, PDL was to receive 75% of the European royalties under the Amended License Agreement with Grünenthal, as well as 80% of the first four commercial milestones worth $35.6 million (or 80% of $44.5 million), up to a capped amount of $195.0 million over the life of the arrangement.

Under the relevant accounting guidance, because of the Company’s significant continuing involvement, the Royalty Monetization has been accounted for as a liability that will be amortized using the effective interest method over the life of the arrangement. In order to determine the amortization of the liability, the Company is required to estimate the total amount of future royalty and milestone payments to be received by ARPI LLC and paid to PDL, up to a capped amount of $195.0 million, over the life of the arrangement. The aggregate future estimated royalty and milestone payments (subject to the capped amount), less the $61.2 million of net proceeds the Company received will be recorded as interest expense over the life of the liability. Consequently, the Company imputes interest on the unamortized portion of the liability and records interest expense relating to the Royalty Monetization accordingly.

The Company periodically assesses the expected royalty and milestone payments using a combination of historical results, internal projections and forecasts from external sources. To the extent such payments are greater or less than the Company’s initial estimates or the timing of such payments is materially different than its original estimates, the Company will prospectively adjust the amortization of the liability and the effective interest rate. During the three months ended June 30, 2020, Grünenthal notified the Company that it was terminating the Amended License Agreement, effective November 13, 2020. The terms of the Grünenthal Agreements were extended to May 12, 2021 to enable Grünenthal to sell down its Zalviso inventory. The rights to market and sell Zalviso in the Zalviso Territory reverted back to the Company on May 12, 2021. There is a continuing obligation on the Company’s part, through the term of the Royalty Monetization with SWK (assignee of PDL), to use commercially reasonable efforts to negotiate a replacement license agreement, or New Arrangement. If the Company is unable to find a New Arrangement, a contingent gain of up to approximately $64 million may be recognized when it is realized upon expiration of the liability at the end of the Royalty Monetization term. Due to the significant judgments and factors related to the estimates of future payments under the Royalty Monetization, there are significant uncertainties surrounding the amount and timing of future payments and the probability of realization of the estimated contingent gain.

The effective interest rate over the life of the liability will be 0% as the Company records interest income over the remaining term of the arrangement as an offset to the interest expense that was recognized in prior periods. The effective interest income rate for the years ended December 31, 2021 and 2020 was approximately 3.5% and 3.6%, respectively.

The following table shows the activity within the liability account during the year ended December 31, 2021 (in thousands):

	Year ended December 31, 2021			Period from inception to December 31, 2021
Liability related to sale of future royalties — beginning balance	$	88,471		$	—
Proceeds from sale of future royalties		—			61,184
Non-cash royalty revenue		(145	)		(1,083	)
Non-cash interest (income) expense recognized		(3,038	)		25,187
Liability related to sale of future royalties as of December 31, 2021	$	85,288		$	85,288

As royalties are remitted to PDL from ARPI LLC, as described in Note 1 “Organization and Summary of Significant Accounting Policies,” the balance of the liability will be effectively repaid over the life of the agreement. The Company will record non-cash royalty revenues and non-cash interest (income) expense within its Consolidated Statements of Operations over the term of the Royalty Monetization. The liability related to the sale of future royalties, current portion, is recorded as accrued liabilities in the Company’s Consolidated Balance Sheets.

Note 11 - Warrants

12 Months Ended

Dec. 31, 2021

Warrants Disclosure [Text Block]

11. Warrants

November 2021 Financing Warrants

On November 15, 2021, the Company entered into a securities purchase agreement with certain investors pursuant to which the Company, in a registered direct offering, sold (i) an aggregate of 17,500,000 shares of the Company's common stock, and (ii) warrants to purchase up to an aggregate of 17,500,000 shares of common stock, for an aggregate purchase price of $14.0 million (see Note 13 “Stockholders’ Equity”). The November 2021 Financing Warrants have an exercise price of $1.00 per share and become exercisable, if the holder’s post-exercise beneficial ownership is less than or equal to 9.99%, 6 months after their issuance date and have a five-year term ( November 15, 2026). All common stock issuable under the issued warrants, were added to the Company’s effective registration statement on November 15, 2021.

The November 2021 Financing warrants were valued at approximately $8.6 million using the Black-Scholes option pricing model as follows: exercise price of $1.00 per share, stock price of $0.7461 per share, expected life of five years, volatility of 91.77%, and a risk-free rate of 1.26%. The common stock and warrants were issued in a unit structure; therefore, in accordance with ASC Topic 815, the aggregate gross proceeds of $14.0 million were allocated to the two securities using the relative fair value method, resulting in the common stock and warrants being allocated values of $8.4 million and $5.6 million, respectively, and recorded to stockholders' equity.

Loan Agreement Warrants

In connection with the Loan Agreement, on May 30, 2019, the Company issued warrants to the Lender and its affiliates, which are exercisable for an aggregate of 176,679 shares of the Company’s common stock with a per share exercise price of $2.83, or the Loan Agreement Warrants. The Loan Agreement Warrants may be exercised on a cashless basis. The Loan Agreement Warrants are exercisable for a term beginning on the date of issuance and ending on the earlier to occur of ten years from the date of issuance or the consummation of certain acquisitions of the Company as set forth in the Loan Agreement Warrants. The number of shares for which the Loan Agreement Warrants are exercisable and the associated exercise price are subject to certain proportional adjustments as set forth in the Loan Agreement Warrants.

The Company estimated the fair value of these Loan Agreement Warrants as of the issuance date to be $0.4 million, which was used in estimating the fair value of the debt instrument and was recorded as equity. The fair value of the Loan Agreement Warrants was calculated using the Black-Scholes option-valuation model, and was based on the strike price of $2.83, the stock price at issuance of $2.66, the ten-year contractual term of the warrants, a risk-free interest rate of 2.22%, expected volatility of 80.22% and 0% expected dividend yield.

As of December 31, 2021, Loan Agreement Warrants to purchase 176,679 shares of common stock issued to the Lender and its affiliates had not been exercised and were still outstanding. These warrants expire in May 2029.

Note 12 - Commitments and Contingencies

12 Months Ended

Dec. 31, 2021

Commitments and Contingencies Disclosure [Text Block]

12. Commitments and Contingencies

Litigation

On June 8, 2021, a securities class action complaint was filed in the U.S. District Court for the Northern District of California against the Company and two of its officers. The plaintiff is a purported stockholder of the Company. The complaint alleges that defendants violated Sections 10(b) and 20(a) of the Exchange Act and SEC Rule 10b-5 by making false and misleading statements and omissions of material fact about the Company’s disclosure controls and procedures with respect to its marketing of DSUVIA. The complaint seeks unspecified damages, interest, attorneys’ fees, and other costs. On December 16, 2021, the Court appointed co-lead plaintiffs. Plaintiffs’ amended complaint was filed on March 7, 2022. The amended complaint names the Company and three of its officers and continues to allege that defendants violated Sections 10(b) and 20(a) of the Exchange Act and SEC Rule 10b-5 by making false and misleading statements and omissions of material fact about the Company’s disclosure controls and procedures with respect to its marketing of DSUVIA. The complaint also alleges a violation of Section 20A of the Exchange Act against the individual defendants for alleged insider trading. Defendants’ motion to dismiss the amended complaint is due May 6, 2022.

On July 6, 2021, a purported shareholder derivative complaint was filed in the U.S. District Court for the Northern District of California. The complaint names ten of the Company’s officers and directors and asserts state and federal claims based on the same alleged misstatements as the shareholder class action complaint. On September 30, 2021, October 26, 2021, and November 17, 2021, three additional purported shareholder derivative complaints were filed in the U.S. District Court for the Northern District of California. The complaints name nine of the Company’s officers and directors and also assert state and federal claims based on the same alleged misstatements as the shareholder class action complaint. All four complaints seek unspecified damages, attorneys’ fees, and other costs. On December 6, 2021, the Court entered an order consolidating all four actions and staying the consolidated action pending the outcome of any motion to dismiss the securities class action. Please see “Part II., Item 1A. Risk Factors—Risks of a General Nature—Litigation may substantially increase our costs and harm our business.”

The Company believes that these lawsuits are without merit and intends to vigorously defend against them. Given the uncertainty of litigation, the preliminary stage of the cases, and the legal standards that must be met for, among other things, class certification and success on the merits, the Company cannot estimate the reasonably possible loss or range of loss that may result from these actions.

Note 13 - Stockholders' Equity

12 Months Ended

Dec. 31, 2021

Stockholders' Equity Note Disclosure [Text Block]

13. Stockholders’ Equity

Common Stock

2021 Underwritten Public Offering

On January 22, 2021, the Company completed an underwritten public offering in which the Company issued and sold 14,500,000 shares of its common stock to the underwriter at a price of $1.7625 per share. On January 27, 2021, the underwriters exercised their option in full and purchased an additional 2,175,000 shares at a price of $1.7625 per share. The total net proceeds from this offering of an aggregate 16,675,000 shares were approximately $28.9 million.

2021 Registered Direct Offering

On November 17, 2021, the Company completed a registered direct offering in which the Company issued and sold 17,500,000 shares of its common stock at a price of $0.80 per share and warrants exercisable for an aggregate of 17,500,000 shares of its common stock at a price of $1.00 per share. The total net proceeds from this offering were approximately $13.9 million. The November 2021 issued shares were valued at approximately $13.1 million based on the closing stock price of $0.7491 per share on November 15, 2021. The common stock and warrants were issued in a unit structure; therefore, in accordance with ASC Topic 815, the aggregate gross proceeds of $14.0 million were allocated to the two securities using the relative fair value method, resulting in the common stock and warrants being allocated values of $8.4 million and $5.6 million, respectively.

2020 Registered Direct Offerings

On July 23, 2020, the Company completed a registered direct offering in which it issued and sold 9,433,962 shares of its common stock at a price of $1.06 per share. The total net proceeds from this offering were approximately $10.0 million, after deducting estimated expenses payable by the Company of $49,000. No underwriter or placement agent participated in the offering.

On December 11, 2020, the Company completed a registered direct offering in which it issued and sold 8,333,333 shares of its common stock at a price of $1.20 per share. The total net proceeds from this offering were approximately $9.9 million, after deducting estimated expenses payable by the Company of $51,000. No underwriter or placement agent participated in the offering.

ATM Agreement

On June 21, 2016, the Company entered into a Controlled Equity Offering^SM Sales Agreement, or the ATM Agreement, with Cantor Fitzgerald & Co., or Cantor, as agent, pursuant to which the Company may offer and sell, from time to time through Cantor, shares of the Company’s common stock, or the Common Stock having an aggregate offering price of up to $40.0 million, or the Shares. On May 9, 2019, the Company increased the aggregate offering price of shares of the Company’s common stock which may be offered and sold under the ATM Agreement by $40.0 million, for a total of $80.0 million, or the Shares. The offering of Shares pursuant to the ATM Agreement will terminate upon the earlier of (a) the sale of all of the Shares subject to the ATM Agreement or (b) the termination of the ATM Agreement by Cantor or the Company, as permitted therein. The Company will pay Cantor a commission rate in the low single digits on the aggregate gross proceeds from each sale of Shares and have agreed to provide Cantor with customary indemnification and contribution rights.

During the year ended December 31, 2021, the Company issued and sold approximately 3.0 million shares of common stock pursuant to the ATM Agreement, and received net proceeds of approximately $7.5 million, after deducting fees and expenses. During the year ended December 31, 2020, the Company issued and sold 876,800 shares of common stock pursuant to the ATM Agreement, for which the Company received net proceeds of approximately $1.4 million.

As of December 31, 2021, the Company had the ability to offer and sell shares of the Company’s common stock having an aggregate offering price of up to $36.1 million under the ATM Agreement.

Stock Plans

2011 Equity Incentive Plan

In January 2011, the Board of Directors adopted, and the Company’s stockholders approved, the 2011 Equity Incentive Plan, or 2011 EIP. The initial aggregate number of shares of the Company’s common stock that were issuable pursuant to stock awards under the 2011 EIP was approximately 1.9 million shares. The number of shares of common stock reserved for issuance under the 2011 EIP automatically increased on January 1 of each year, starting on January 1, 2012 and continuing through January 1, 2020, by 4% of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year, or such lesser number of shares of common stock as determined by the Board of Directors.

As of June 16, 2020, no more awards may be granted under the 2011 Equity Incentive Plan, or the 2011 EIP, although all outstanding stock options and other stock awards previously granted under the 2011 EIP will continue to remain subject to the terms of the 2011 EIP.

Amended 2020 Plan

On June 16, 2020, at the 2020 Annual Meeting of Stockholders of the Company, the Company’s stockholders, upon the recommendation of the Company’s Board of Directors, approved the Company’s 2020 Equity Incentive Plan, or the 2020 EIP.

The initial aggregate number of shares of the Company’s common stock issuable pursuant to stock awards under the 2020 EIP was 5,500,000 shares. In addition, the share reserve will be increased by the number of returning shares, if any, as such shares become available from time to time under the 2011 EIP, for an additional number of shares not to exceed 14,892,170 shares. The term of any option granted under the 2020 EIP is determined on the date of grant but shall not be longer than 10 years. The Company issues new shares for settlement of vested restricted stock units and exercises of stock options. The Company does not have a policy of purchasing its shares relating to its stock-based programs.

On June 17, 2021, at the 2021 Annual Meeting of Stockholders of the Company, upon the recommendation of the Company’s Board of Directors, the Company’s stockholders approved an amendment and restatement of the Company’s 2020 Equity Incentive Plan, or 2020 Plan, or as amended and restated, the Amended 2020 Plan, to increase the number of authorized shares reserved for issuance thereunder by 4,300,000 shares, subject to adjustment for certain changes in the Company’s capitalization. The aggregate number of shares of the Company’s common stock that may be issued under the Amended 2020 Plan will not exceed the sum of: (i) 4,300,000 shares approved in connection with the adoption of the Amended 2020 Plan, (ii) 5,500,000 shares approved in connection with the original adoption of the 2020 Plan, and (iii) certain shares subject to outstanding awards granted under the 2011 Equity Incentive Plan that may become available for issuance under the 2020 Plan and Amended 2020 Plan, as such shares become available from time to time.

Amended and Restated 2011 Employee Stock Purchase Plan

Additionally, on June 16, 2020, the Company’s stockholders, upon the recommendation of the Company’s Board of Directors, approved the Amended and Restated 2011 Employee Stock Purchase Plan, or the Amended ESPP, which increased the aggregate number of shares of the Company’s common stock reserved for issuance under the 2011 Employee Stock Purchase Plan, or ESPP, to 4,900,000 shares, subject to adjustment for certain changes in the Company’s capitalization, and removed the “evergreen” provision from the ESPP.

In the year ended December 31, 2021, there were 297,959 shares issued under the Amended ESPP. The weighted average fair value of shares issued under the Amended ESPP in 2021 and 2020 was $1.01 and $1.09 per share, respectively. As of December 31, 2021, there were 4,456,364 shares available for future grant under the Amended ESPP.

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Note 14 - Stock Based Compensation

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Text Block]

14. Stock-Based Compensation

The Company recorded total stock-based compensation expense for stock options, stock awards and the Amended ESPP as follows (in thousands):

	December 31, 2021		December 31, 2020
Cost of goods sold	$	92	$	123
Research and development		813		764
Selling, general and administrative		3,704		3,537
Total	$	4,609	$	4,424

The following table summarizes restricted stock unit activity under the Company’s Equity Incentive Plans:

				Weighted
	Number of			*Average*
	*Restricted*			Grant Date
	Stock Units			Fair Value
Restricted stock units outstanding, January 1, 2020		988,645		$	2.53
Granted		908,300			1.30
Vested		(304,810	)		2.53
Forfeited		(194,152	)		2.16
Restricted stock units outstanding, December 31, 2020		1,397,983		$	1.79
Granted		1,149,632			1.68
Vested		(587,214	)		1.89
Forfeited		(186,025	)		1.58
Restricted stock units outstanding, December 31, 2021		1,774,376		$	1.71

The following table summarizes stock option activity under the Company’s Equity Incentive Plans:

	Number of Stock Options Outstanding			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value
								(in thousands)
December 31, 2020		12,813,022		$	3.20
Granted		2,667,612			1.82
Forfeited		(375,432	)		1.79
Expired		(801,749	)		3.03
Exercised		(19,403	)		0.84
December 31, 2021		14,284,050		$	2.99		5.8	$	—
Vested and exercisable options—December 31, 2021		10,496,744		$	3.42		4.8	$	—
Vested and expected to vest—December 31, 2021		14,284,050		$	2.99		5.8	$	—

As of December 31, 2021, there were 7,858,933 shares available for future grant under the 2020 EIP.

Additional information regarding the Company’s stock options outstanding and vested and exercisable as of December 31, 2021 is summarized below:

			Options Outstanding						Options Vested and Exercisable
Exercise Prices			Number of Stock Options Outstanding		Weighted-Average Remaining Contractual Life (Years)		Weighted-Average Exercise Price per Share		Shares Subject to Stock Options		Weighted-Average Exercise Price per Share
$0.72	-	$1.12		695,482		8.1	$	0.85		280,047	$	0.84
$1.26	-	$1.89		3,402,418		8.9	$	1.80		496,679	$	1.67
$2.00	-	$3.00		5,310,550		6.1	$	2.44		4,856,618	$	2.43
$3.10	-	$4.65		3,066,819		3.8	$	3.37		3,054,619	$	3.38
$4.73	-	$7.10		1,295,781		1.8	$	5.71		1,295,781	$	5.71
$8.18	-	$12.27		513,000		2.1	$	10.28		513,000	$	10.28
				14,284,050		5.8	$	2.99		10,496,744	$	3.42

The weighted average grant-date fair value of options granted during the years ended December 31, 2021 and 2020 was $1.24 and $0.92 per share, respectively. As of December 31, 2021, total stock-based compensation expense related to unvested options to be recognized in future periods was $3.8 million which is expected to be recognized over a weighted-average period of 2.1 years. The grant date fair value of shares vested during the years ended December 31, 2021 and 2020 was $2.4 million and $3.6 million, respectively. The total intrinsic value of options exercised during the years ended December 31, 2021 and 2020 was $5.7 thousand and $0.0 million, respectively.

On March 3, 2021, the Company granted 1.27 million performance-based stock options to certain of its executive officers, which are included in the stock option tables and associated disclosures above. The awards were granted under the 2020 EIP with an exercise price of $1.88 per share, the closing sales price as reported on the Nasdaq on the date of grant. The performance-based stock options are eligible to vest subject to the satisfaction of the service-based vesting requirements and attainment of share price target goals, a market-based condition. No performance-based stock options vested during the year ended December 31, 2021, and there were no performance-based stock options granted for the year ended December 31, 2020.

The Company uses the Monte Carlo Simulation model to evaluate the derived service period and fair value of awards with market conditions, including assumptions of historical volatility and risk-free interest rate commensurate with the vesting term.

The Company used the following assumptions to calculate the fair value of each performance-based stock option:

	Year Ended December 31,
	2021			2020
Derived service period (in years)	2.3	–	2.6		—
Risk-free interest rate		1.5%			—
Expected volatility		90%			—
Expected dividend rate		0%			—

The Company used the following assumptions to calculate the fair value of each time-based stock option:

	Year Ended December 31,
	2021				2020
Expected term (in years)		6.0	-	6.2			6.2
Risk-free interest rate		0.9%	-	1.3%		0.4%	-	1.5%
Expected volatility			90%				83%
Expected dividend rate			0%				0%

Note 15 - Net Loss Per Share of Common Stock

12 Months Ended

Dec. 31, 2021

Earnings Per Share [Text Block]

15. Net Loss per Share of Common Stock

The Company’s basic net loss per share of common stock is calculated by dividing the net loss by the weighted average number of shares of common stock outstanding for the period. The diluted net loss per share of common stock is computed by giving effect to all potential common stock equivalents outstanding for the period determined using the treasury stock method. For purposes of this calculation, options to purchase common stock, restricted stock units and warrants to purchase common stock were considered to be common stock equivalents. In periods with a reported net loss, common stock equivalents are excluded from the calculation of diluted net loss per share of common stock if their effect is antidilutive.

The following outstanding shares of common stock equivalents were excluded from the computation of diluted net loss per share of common stock for the periods presented because including them would have been antidilutive:

	Year Ended December 31,
	2021		2020
ESPP, RSUs and stock options to purchase common stock		16,328,426		14,541,005
Common stock warrants		17,676,679		176,679

Note 16 - Accrued Liabilities

12 Months Ended

Dec. 31, 2021

Accounts Payable and Accrued Liabilities Disclosure [Text Block]

16. Accrued Liabilities

Accrued liabilities consist of the following (in thousands):

	December 31,
	2021		2020
Accrued compensation and employee benefits	$	2,974	$	3,323
Accrued professional services		1,523		179
Accrued product returns and sales allowances		775		656
Deferred revenue		86		49
Other accrued liabilities		1,166		838
Total accrued liabilities	$	6,524	$	5,045

Note 17 - 401(k) Plan

12 Months Ended

Dec. 31, 2021

Retirement Benefits [Text Block]

17. 401(k) Plan

The Company sponsors a 401(k) plan that stipulates that eligible employees can elect to contribute to the 401(k) plan, subject to certain limitations. Pursuant to the 401(k) plan, the Company makes a matching contribution of up to 4% of the related compensation. Under the vesting schedule, employees have ownership in the matching employer contributions based on the number of years of vesting service completed. Company contributions were $0.4 million and $0.5 million for the years ended December 31, 2021 and 2020, respectively.

The entire disclosure for retirement benefits.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
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Note 18 - Income Taxes

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Text Block]

18. Income Taxes

The Company recorded a provision for income taxes of $5.0 thousand and $4.0 thousand during the years ended December 31, 2021 and 2020, respectively.

Net deferred tax assets as of December 31, 2021 and 2020 consist of the following (in thousands):

	December 31, 2021			December 31, 2020
Deferred tax assets:
Accruals and other	$	3,989		$	4,136
Research credits		7,275			7,275
Net operating loss carryforward		75,452			65,274
Section 59(e) R&D expenditures		5,070			7,473
Deferred revenue		19,666			20,848
Total deferred tax assets		111,452			105,006
Valuation allowance		(111,452	)		(105,006	)
Net deferred tax assets	$	—		$	—

Reconciliations of the statutory federal income tax to the Company’s effective tax during the years ended December 31, 2021 and 2020 are as follows (in thousands):

	Year Ended December 31,
	2021			2020
Tax at statutory federal rate	$	(7,370	)	$	(8,486	)
State tax—net of federal benefit		231			(3,587	)
Stock options		718			636
Other		(20	)		—
Change in valuation allowance		6,446			11,441
Provision for income taxes	$	5		$	4

ASC 740 requires that the tax benefit of net operating losses, temporary differences and credit carryforwards be recorded as an asset to the extent that management assesses that realization is “more likely than not.” Realization of deferred tax assets is dependent on future taxable income, if any, the timing and the amount of which are uncertain. Accordingly, the deferred tax assets have been fully offset by a valuation allowance. The valuation allowance increased by $6.4 million and $11.4 million during the years ended December 31, 2021 and 2020, respectively.

As of December 31, 2021, the Company had federal net operating loss carryforwards of $308.5 million, of which $114.9 million federal net operating losses generated before January 1, 2018 will begin to expire in 2029. Federal net operating losses of $193.6 million generated from 2018 to 2021 will carryforward indefinitely but are subject to the 80% taxable income limitation. As of December 31, 2021, the Company had state net operating loss carryforwards of $154.7 million, which begin to expire in 2028.

As of December 31, 2021, the Company had federal research credit carryovers of $6.5 million, which begin to expire in 2026. As of December 31, 2021, the Company had state research credit carryovers of $4.0 million, which will carryforward indefinitely.

Under Section 382 of the Internal Revenue Code of 1986, as amended, if a corporation undergoes an “ownership change,” generally defined as a greater than 50% change (by value) in its equity ownership over a three-year period, the corporation’s ability to use its pre-change net operating loss carryforwards and other pre-change tax attributes, such as research credits, to offset its post-change income may be limited. Based on an analysis performed by the Company as of December 31, 2013, it was determined that two ownership changes have occurred since inception of the Company. The first ownership change occurred in 2006 at the time of the Series A financing and, as a result of the change, $1.4 million in federal and state net operating loss carryforwards will expire unutilized. In addition, $26 thousand in federal and state research and development credits will expire unutilized. The second ownership change occurred in July 2013 at the time of the underwritten public offering; however, the Company believes the resulting annual imposed limitation on use of pre-change tax attributes is sufficiently high that the limit itself will not result in unutilized pre-change tax attributes.

Uncertain Tax Positions

A reconciliation of the beginning and ending balances of the unrecognized tax benefits during the years ended December 31, 2021 and 2020 is as follows (in thousands):

	Year Ended December 31,
	2021		2020
Unrecognized benefit—beginning of period	$	2,635	$	2,635
Gross increases—prior period tax positions		—		—
Gross increases—current period tax positions		—		—
Unrecognized benefit—end of period	$	2,635	$	2,635

The entire amount of the unrecognized tax benefits would not impact the Company’s effective tax rate if recognized.

There were no accrued interest or penalties related to unrecognized tax benefits in the years ended December 31, 2021 and 2020. The Company files income tax returns in the United States, California, and other states. The tax years 2005 through 2014, and 2016 through 2021, remain open in all jurisdictions. The Company is not currently under examination by income tax authorities in federal, state or other foreign jurisdictions. The Company does not anticipate any significant changes within 12 months of this reporting date of its uncertain tax positions.

In March 2020, the Coronavirus Aid, Relief and Economic Security, or CARES, Act was signed into law. The CARES Act included several tax changes as part of its economic package. These changes principally related to expanded net operating loss carryback periods, increases to interest deductibility limitations, and accelerated alternative minimum tax refunds. The Company has evaluated these items and determined that the items do not have a material effect on the Company's financial statements as of December 31, 2021. Additionally, the CARES Act enacted the Employee Retention Credit, or ERC, to incentivize companies to retain employees, which was subsequently modified by extension of the CARES Act. Under the provisions of the CARES Act and its subsequent extension, the Company was eligible for ERCs, subject to certain criteria. Accordingly, the Company has recorded a reduction in payroll taxes related to ERCs claimed for $1.4 million in the year ended December 31, 2021. These credits are recorded in the Consolidated Statements of Operations as an offset to the related payroll expenses in the respective operating costs and expenses line item. Such claimed ERCs not settled prior to year-end in the amount of $1.4 million are expected to be settled shortly thereafter and are disclosed within prepaid expenses and other current assets on the Company’s Consolidated Balance Sheets at December 31, 2021.

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

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Note 19 - Subsequent Events

12 Months Ended

Dec. 31, 2021

Subsequent Events [Text Block]

19. Subsequent Events

On January 7, 2022, the Company closed the Merger Agreement with Lowell in a transaction for consideration of approximately $32.5 million plus net cash acquired and certain other adjustments. Pursuant to the terms of the Merger Agreement, all options to purchase capital stock and all shares of Lowell capital stock issued and outstanding immediately before the effective time of the merger were cancelled in exchange for the right to receive (i) 9,009,538 shares of AcelRx common stock, and cash in the amount of $3,519,129, (ii) 1,396,526 shares of AcelRx common stock to be held back to satisfy any potential indemnification and other obligations of Lowell and its securityholders, and (iii) up to $26.0 million of contingent consideration payable in cash or stock at AcelRx's option, upon the achievement of regulatory and sales-based milestones.

The 1,396,526 of held back shares of AcelRx common stock issued in connection with the closing was calculated based on a fixed value of $0.57284 per share, which is the arithmetic average of the daily volume weighted average price per share of AcelRx common stock during the five consecutive full trading days ending on and including the last full trading day immediately prior to the date of the closing. The shares issued pursuant to the Merger Agreement were issued in private placements pursuant to the exemption from registration under Section 4(a)(2) of the Securities Act of 1933, as amended, or the Securities Act, including Rule 506 of Regulation D promulgated under the Securities Act, or Regulation D, without general solicitation as a transaction not involving any public offering.

The Merger Agreement will be accounted for in the first quarter of 2022 as an acquisition of assets that does not meet the definition of a business. The asset acquisition does not constitute a business as substantially all of the fair value of the gross assets acquired was concentrated in Lowell’s intellectual property, including NIYAD™ and LTX-608. The acquired assets and liabilities will be recorded at their relative fair values and the contingent consideration will be recorded when it becomes probable of achievement or the consideration becomes payable. Accordingly, the Company has classified $1.9 million of expenses related to the Merger Agreement as Other assets in the Consolidated Balance Sheet at December 31, 2021.

Schedule II - Valuation and Qualifying Accounts

12 Months Ended

Dec. 31, 2021

SEC Schedule, 12-09, Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]

SCHEDULE II: VALUATION AND QUALIFYING ACCOUNTS
(in thousands)


			*Additions*
	*Balance at*		*Charged as a*					*Balance at*
	*Beginning of*		*Reduction to*					*End of*
Description	*Period*		*Revenue*		Deductions*			*Period*
Sales & return allowances, discounts, chargebacks and rebates:
Year ended December 31, 2021	$	668	$	1,012	$	(900	)	$	780
Year ended December 31, 2020	$	161	$	645	$	(138	)	$	668

* Deductions to sales discounts and allowances relate to discounts or allowances actually taken or paid.

Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Business Description of Entity [Policy Text Block]

The Company

Termination of Grünenthal Agreements

Basis of Accounting, Policy [Policy Text Block]

Basis of Presentation

Reclassification, Comparability Adjustment [Policy Text Block]

Reclassifications

Consolidation, Policy [Policy Text Block]

Principles of Consolidation

The Consolidated Financial Statements include the accounts of the Company and its wholly owned subsidiary, ARPI LLC, which was formed in September 2015 for the sole purpose of facilitating the Royalty Monetization with PDL of the expected royalty stream and milestone payments due from the sales of Zalviso in the European Union by its commercial partner, Grünenthal, pursuant to the Amended License Agreement. All intercompany accounts and transactions have been eliminated in consolidation. Refer to Note 10 “Liability Related to Sale of Future Royalties” for additional information.

Use of Estimates, Policy [Policy Text Block]

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the Consolidated Financial Statements and accompanying notes. Management believes its most significant accounting estimates relate to revenue recognition, inventory valuation and the liability related to the sale of future royalties. Management evaluates its estimates on an ongoing basis including critical accounting policies. Estimates are based on historical experience and on various other market-specific and other relevant assumptions that the Company believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ from those estimates.

Cash, Cash Equivalents, and Marketable Securities [Policy Text Block]

Cash, Cash Equivalents and Short-Term Investments

The Company considers all highly liquid investments with an original maturity (at date of purchase) of three months or less to be cash equivalents. Cash and cash equivalents consist of cash on deposit with banks.

All marketable securities are classified as available-for-sale and consist of commercial paper, U.S. government sponsored enterprise debt securities and corporate debt securities. These securities are carried at estimated fair value, which is based on quoted market prices or observable market inputs of almost identical assets, with unrealized gains and losses included in accumulated other comprehensive income (loss). The amortized cost of securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion is included in interest income or expense. The cost of securities sold is based on specific identification. The Company’s investments are subject to a periodic impairment review for other-than-temporary declines in fair value. The Company’s review includes the consideration of the cause of the impairment including the creditworthiness of the security issuers, the number of securities in an unrealized loss position, the severity and duration of the unrealized losses and the Company’s intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in the market value. When the Company determines that the decline in fair value of an investment is below its accounting basis and this decline is other-than-temporary, it reduces the carrying value of the security it holds and records a loss in the amount of such decline.

Fair Value Measurement, Policy [Policy Text Block]

Fair Value of Financial Instruments

The Company measures and reports its cash equivalents, investments and financial liabilities at fair value. Fair value is defined as the exchange price that would be received for an asset or an exit price paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The fair value hierarchy defines a three-level valuation hierarchy for disclosure of fair value measurements as follows:

Level I—Unadjusted quoted prices in active markets for identical assets or liabilities;

Level II—Inputs other than quoted prices included within Level I that are observable, unadjusted quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and

Level III—Unobservable inputs that are supported by little or no market activity for the related assets or liabilities.

The categorization of a financial instrument within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement.

Segment Reporting, Policy [Policy Text Block]

Segment Information

The Company operates in a single segment, the development and commercialization of product candidates and products for the treatment of pain. The Company’s product sales revenue consists of sales of DSUVIA in the United States and, through May 2021, sales of Zalviso in Europe by Grünenthal. The Company’s contract and collaboration revenue consists of non-cash royalty revenue, royalty revenue, and other revenue under the Grünenthal Agreements and license revenue under the DZUVEO Agreement.

Concentration Risk, Credit Risk, Policy [Policy Text Block]

Concentration of Risk

The Company invests cash that is currently not being used for operational purposes in accordance with its investment policy in debt securities of U.S. government sponsored agencies, commercial paper and overnight deposits. The Company is exposed to credit risk in the event of default by the institutions holding the cash equivalents and available-for-sale securities to the extent recorded on the Consolidated Balance Sheets.

The Company relies on a single third-party supplier for the supply of sufentanil, the active pharmaceutical ingredient in DSUVIA and Zalviso, and various sole-source third-party contract manufacturer organizations to manufacture the DSUVIA SDA.

DSUVIA sales are concentrated with the DoD and with a limited number of wholesalers in the United States. Zalviso was sold in Europe by Grünenthal through May 2021. In July 2021, Aguettant was granted an exclusive license to commercialize DZUVEO in Europe. DZUVEO sales in Europe by Aguettant have not commenced as of December 31, 2021.

Revenue and accounts receivable have been concentrated with these customers.

Revenues from customers that accounted for 10% or more of our total revenues during the years ended December 31, 2021 and 2020 are as follows:

	Year Ended December 31,
Percent of Total Revenue	2021			2020
Aguettant		61.9	%		0	%
Grünenthal		11.7	%		74.0	%
DoD		0.3	%		16.9	%
Wholesaler A		15.9	%		3.9	%

Receivable [Policy Text Block]

Accounts Receivable, net

The need for a bad debt allowance is evaluated each reporting period based on the Company’s assessment of the credit worthiness of its customers or any other potential circumstances that could result in bad debt.

The Company believes that the entire accounts receivable balance as of December 31, 2021 is collectible and there was no bad debt allowance provided as of December 31, 2020.

Accounts receivable, net from customers that accounted for 10% or more of our total accounts receivable balance as of December 31, 2021 and 2020 are as follows:

	As of December 31,
Percent of Accounts Receivable, Net	2021			2020
Customer A		73	%		12	%
Customer B		0	%		79	%

Inventory, Policy [Policy Text Block]

Inventories, net

Inventories are valued at the lower of cost or net realizable value. Cost is determined using the first-in, first-out method for all inventories. Inventory includes the cost of the active pharmaceutical ingredients, or API, raw materials and third-party contract manufacturing and packaging services. Indirect overhead costs associated with production and distribution are allocated to the appropriate cost pool and then absorbed into inventory based on the units produced or distributed, assuming normal capacity, in the applicable period. Indirect overhead costs in excess of normal capacity are recorded as period costs in the period incurred.

The Company's policy is to write down inventory that has become obsolete, inventory that has a cost basis in excess of its expected net realizable value and inventory in excess of expected requirements. The Company periodically evaluates the carrying value of inventory on hand for potential excess amount over demand using the same lower of cost or net realizable value approach as that used to value the inventory.

Property, Plant and Equipment, Policy [Policy Text Block]

Property and Equipment, net

Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets, generally three to five years. Leasehold improvements are amortized over the shorter of the estimated useful life of the improvements or the remaining lease term. Expenditures for repairs and maintenance, which do not extend the useful life of the property and equipment, are expensed as incurred. Upon retirement, the asset cost and related accumulated depreciation are relieved from the accompanying Consolidated Balance Sheets. Gains and losses associated with dispositions are reflected as a component of interest income and other income, net in the accompanying Consolidated Statements of Operations.

Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]

Impairment of Long-Lived Assets

The Company periodically assesses the impairment of long-lived assets and, if indicators of asset impairment exist, the Company assesses the recoverability of the affected long-lived assets by determining whether the carrying value of such assets can be recovered through an analysis of the undiscounted future expected operating cash flows. If impairment is indicated, the Company records the amount of such impairment for the excess of the carrying value of the asset over its estimated fair value. For example, if the Company is not successful in its commercialization of DSUVIA, and if approved, Zalviso, purchased equipment and manufacturing-related facility improvements the Company has made at its contract manufacturers could become impaired. The Company may determine that it is no longer probable that the Company will realize the future economic benefit associated with the costs of these assets through future manufacturing activities, and if so, the Company would record an impairment charge associated with these assets.

Contingent Put Option, Policy [Policy Text Block]

Contingent put option

The contingent put option associated with the Company’s Loan Agreement with Oxford is recorded as a liability. Changes in the fair value of the contingent put option are recognized as interest income and other income (expense), net in the Consolidated Statements of Operations. For further discussion, see Note 8 “Long-Term Debt”.

Lessee, Leases [Policy Text Block]

Leases

The Company follows the provisions of ASU No. 2016-02, Leases (Topic 842). At the inception of an arrangement, the Company determines whether the arrangement is, or contains, a lease based on the unique facts and circumstances present. Operating lease liabilities and their corresponding right-of-use assets are recorded based on the present value of lease payments over the expected lease term. The interest rate implicit in lease contracts is typically not readily determinable. As such, the Company utilizes its incremental borrowing rate, which is the rate incurred to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment. Certain adjustments to the right-of-use asset may be required for items such as initial direct costs paid or incentives received.

Lease expense is recognized over the expected term on a straight-line basis. Operating leases are recognized on the Consolidated Balance Sheets as operating lease right-of-use assets, operating lease liabilities current and operating lease liabilities non-current.

Revenue [Policy Text Block]

Revenue from Contracts with Customers

The Company follows the provisions of Accounting Standards Codification, or ASC, Topic 606, Revenue from Contracts with Customers. This guidance provides a unified model to determine how revenue is recognized. The Company recognizes revenue upon transfer of control of promised products or services to customers in an amount that reflects the consideration the Company expects to receive in exchange for those products or services. The Company sells its products primarily through wholesale and specialty distributors.

In determining the appropriate amount of revenue to be recognized as it fulfills its obligations under its agreements, the Company performs the following steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations, including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations based on estimated selling prices; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation.

Product sales revenue

The Company sells its product primarily through distributors. Revenues from product sales are recognized when distributors obtain control of the Company’s product, which occurs at a point in time, upon delivery to such distributors. These distributors subsequently resell the product to certified medically supervised healthcare settings. In addition to distribution agreements with these customers, the Company enters into arrangements with group purchasing organizations, or GPOs, and other certified medically supervised healthcare settings that provide for privately negotiated discounts with respect to the purchase of its products. For revenue recognition under bill-and-hold arrangements, wherein the customer agrees to buy product from the Company but requests delivery at a later date, the Company deems that control passes to the customer when the product is ready for delivery. The Company recognizes revenue under these types of arrangements when a signed agreement is in place, the transaction is billable, the customer has significant risk and rewards for the product and the ability to direct the asset, the product has been set aside specifically for the customer, and the product cannot be redirected to another customer. Revenue from product sales is recorded at the transaction price, net of estimates for variable consideration consisting of chargebacks, government rebates, returns, distribution fees, GPO fees and product returns. Variable consideration is recorded at the time product sales are recognized resulting in a reduction in product revenue. The amount of variable consideration that is included in the transaction price may be constrained and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. Variable consideration is estimated using the most-likely amount method, which is the single-most likely outcome under a contract and is typically at the stated contractual rate. Where appropriate, these estimates take into consideration a range of possible outcomes that are probability-weighted in accordance with the expected value method under ASC Topic 606 for relevant factors. These factors include current contractual and statutory requirements, specific known market events and trends, industry data, and/or forecasted customer buying and payment patterns. Actual amounts of consideration ultimately received may differ from the Company’s estimates. If actual results vary materially from the Company’s estimates, the Company will adjust these estimates, which will affect revenue from product sales and earnings in the period such estimates are adjusted. These estimates include:

Chargebacks – The Company’s customers subsequently resell its product to qualified healthcare providers. In addition to distribution agreements with customers, the Company enters into arrangements with qualified healthcare providers that provide discounts with respect to the purchase of its product. Chargebacks represent the estimated obligations resulting from contractual commitments to sell product to qualified healthcare providers at prices lower than the list prices charged to customers who directly purchase the product from the Company. Customers charge the Company for the difference between what they pay for the product and the ultimate selling price to the qualified healthcare providers. These reserves are established in the same period that the related revenue is recognized, resulting in a reduction of product revenue-related accrued liabilities on the Consolidated Balance Sheets. Chargeback amounts are determined at the time of resale to the qualified healthcare providers by customers, and the Company issues credits for such amounts generally within a few weeks of the customer's notification to the Company of the resale. Reserves for chargebacks consists of credits that the Company expects to issue for units that remain in the distribution channel inventories at each reporting period end that the Company expects will be sold to the qualified healthcare providers, and chargebacks for units that the Company’s customers have sold to the qualified healthcare providers, but for which credits have not been issued.

Government Rebates – The Company is subject to discount obligations under state Medicaid programs. The Company estimates its Medicaid rebates, and reserves are recorded in the same period the related product revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability that is included in accrued liabilities on the Consolidated Balance Sheet.

Returns – The Company allows its distributors to return product for credit 6 months prior to, and up to 12 months after, the product expiration date. As such, there may be a significant period of time between the time the product is shipped and the time the credit is issued on returned product.

Distribution Fees – Distribution fees include fees paid to certain customers for sales order management, data and distribution services. Distribution fees are recorded as a reduction of revenue in the period the related product revenue is recognized.

GPO Fees – The Company pays administrative fees to GPOs for services and access to data. These fees are based on contracted terms and are paid after the quarter in which the product was purchased by the GPOs’ members.

Trade Discounts and Allowances - The Company provides its customers with discounts which include early payment incentives that are explicitly stated in its contracts and are recorded as a reduction of revenue in the period the related product revenue is recognized.

The Company believes its estimated allowances for chargebacks, government rebates and product returns require a high degree of judgment and are subject to change based on its limited experience and certain quantitative and qualitative factors. The Company believes its estimated allowances for distribution fees, GPO fees and trade discounts and allowances do not require a high degree of judgment because the amounts are settled within a relatively short period of time. The Company will continue to assess its estimates of variable consideration as it accumulates additional historical data and will adjust these estimates accordingly. Changes in product revenue allowance estimates could materially affect the Company’s results of operations and financial position.

Contract and other collaboration revenue

The Company generates revenue from collaboration agreements. These agreements typically include payments for upfront signing or license fees, cost reimbursements for development and manufacturing services, milestone payments, product sales, and royalties on licensee’s future product sales. Product sales related revenue under these collaboration agreements is classified as product sales revenue, while other revenue generated from collaboration agreements is classified as contract and other collaboration revenue.

Performance Obligations

A performance obligation is a promise in a contract to transfer a distinct good or service to the customer and is the unit of account in ASC Topic 606. The Company’s performance obligations include delivering product to its distributors, commercialization license rights, development services, services associated with the regulatory approval process, joint steering committee services, demonstration devices, manufacturing services, material rights for discounts on manufacturing services, and product supply.

The Company has optional additional items in contracts, which are considered marketing offers and are accounted for as separate contracts when the customer elects such options. Arrangements that include a promise for future commercial product supply and optional research and development services at the customer’s or the Company’s discretion are generally considered as options. The Company assesses if these options provide a material right to the licensee and if so, such material rights are accounted for as separate performance obligations. If the Company is entitled to additional payments when the customer exercises these options, any additional payments are recorded in revenue when the customer obtains control of the goods or services.

Transaction Price

The Company has both fixed and variable consideration. Variable consideration for product revenue is described as Net product sales in the Consolidated Statements of Operations. For collaboration agreements, non-refundable upfront fees and product supply selling prices are considered fixed, while milestone payments are identified as variable consideration when determining the transaction price. Funding of research and development activities is considered variable until such costs are reimbursed at which point, they are considered fixed. The Company allocates the total transaction price to each performance obligation based on the relative estimated standalone selling prices of the promised goods or services for each performance obligation.

At the inception of each arrangement that includes milestone payments, the Company evaluates whether the milestones are considered probable of being achieved and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the value of the associated milestone (such as a regulatory submission by the Company) is included in the transaction price. Milestone payments that are not within the control of the Company, such as approvals from regulators, are not considered probable of being achieved until those approvals are received.

For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (a) when the related sales occur, or (b) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied).

Allocation of Consideration

As part of the accounting for collaboration arrangements, the Company must develop assumptions that require judgment to determine the stand-alone selling price of each performance obligation identified in the contract. Estimated selling prices for license rights and material rights for discounts on manufacturing services are calculated using an income approach model and can include the following key assumptions: the development timeline, sales forecasts, costs of product sales, commercialization expenses, discount rate, the time which the manufacturing services are expected to be performed, and probabilities of technical and regulatory success. For all other performance obligations, the Company uses a cost-plus margin approach.

Timing of Recognition

Significant management judgment is required to determine the level of effort required under collaboration arrangements and the period over which the Company expects to complete its performance obligations under the arrangement. The Company estimates the performance period or measure of progress at the inception of the arrangement and re-evaluates it each reporting period. This re-evaluation may shorten or lengthen the period over which revenue is recognized. Changes to these estimates are recorded on a cumulative catch-up basis. If the Company cannot reasonably estimate when its performance obligations either are completed or become inconsequential, then revenue recognition is deferred until the Company can reasonably make such estimates. Revenue is then recognized over the remaining estimated period of performance using the cumulative catch-up method. Revenue is recognized for products at a point in time when control of the product is transferred to the customer in an amount that reflects the consideration the Company expects to be entitled to in exchange for those product sales, which is typically once the product physically arrives at the customer, and for licenses of functional intellectual property at the point in time the customer can use and benefit from the license. For performance obligations that are services, revenue is recognized over time proportionate to the costs that the Company has incurred to perform the services using the cost-to-cost input method.

Cost of Goods and Service [Policy Text Block]

Cost of Goods Sold

Cost of goods sold for product revenue includes third party manufacturing costs, shipping and handling costs, and indirect overhead costs associated with production and distribution which are allocated to the appropriate cost pool and recognized when revenue is recognized. Indirect overhead costs in excess of normal capacity are recorded as period costs in the period incurred.

Under the Grünenthal Agreements, the Company sold Zalviso to Grünenthal at predetermined, contractual transfer prices that were less than the direct costs of manufacturing and recognized indirect costs as period costs where they were in excess of normal capacity and not recoverable on a lower of cost or net realizable value basis. Cost of goods sold for Zalviso shipped to Grünenthal included the inventory costs of API, third-party contract manufacturing costs, packaging and distribution costs, shipping, handling and storage costs, depreciation and costs of the employees involved with production.

Research and Development Expense, Policy [Policy Text Block]

Research and Development Expenses

Research and development costs are charged to expense when incurred. Research and development expenses include salaries, employee benefits, including stock-based compensation, consultant fees, laboratory supplies, costs associated with clinical trials and manufacturing, including contract research organization fees, other professional services and allocations of corporate costs. The Company reviews and accrues clinical trial expenses based on work performed, which relies on estimates of total costs incurred based on patient enrollment, completion of patient studies and other events.

Share-based Payment Arrangement [Policy Text Block]

Stock-Based Compensation

Compensation expense for all stock-based payment awards made to employees and directors, including employee stock options and restricted stock units related to the 2020 Equity Incentive Plan, or 2020 EIP, the 2011 Equity Incentive Plan, or 2011 EIP, and employee share purchases related to the Amended and Restated 2011 Employee Stock Purchase Plan, or ESPP, is based on estimated fair values at grant date. The Company determines the grant date fair value of the awards using the Black-Scholes option-pricing model and generally recognizes the fair value as stock-based compensation expense on a straight-line basis over the vesting period of the respective awards. The Company applies the graded-vesting attribution method to awards with market conditions that include graded-vesting features. Additionally, the Company uses the Monte Carlo Simulation model to evaluate the derived service period and fair value of awards with market conditions, including assumptions of historical volatility and risk-free interest rate commensurate with the vesting term.

The Black-Scholes option pricing model requires inputs such as expected term, expected volatility and risk-free interest rate. These inputs are subjective and generally require significant analysis and judgment to develop. The expected term, which represents the period of time that options granted are expected to be outstanding, is derived by analyzing the historical experience of similar awards, giving consideration to the contractual terms of the stock‑based awards, vesting schedules and expectations of future employee behavior. Expected volatilities are estimated using the historical stock price performance over the expected term of the option, which are adjusted as necessary for any other factors which may reasonably affect the volatility of AcelRx’s stock in the future. The risk‑free interest rate is based on the U.S. Treasury yield in effect at the time of the grant for the expected term of the award. The Company recognizes forfeitures when they occur and does not anticipate paying dividends in the near future.

Warrants, Policy [Policy Text Block]

Warrants Issued in Connection with Financings

The Company generally accounts for warrants issued in connection with debt and equity financings as a component of equity, unless the warrants include a conditional obligation to issue a variable number of shares or there is a deemed possibility that the Company may need to settle the warrants in cash. For warrants issued with a conditional obligation to issue a variable number of shares or the deemed possibility of a cash settlement, the Company records the fair value of the warrants as a liability at each balance sheet date and records changes in fair value in other (income) expense in the Consolidated Statements of Operations.

Costs Associated with Exit or Disposal Activities or Restructurings, Policy [Policy Text Block]

Restructuring Costs

The Company's restructuring costs consist of employee termination benefit costs. Liabilities for costs associated with the cost reduction plan are recognized when the liability is incurred and are measured at fair value. One-time termination benefits are expensed at the date the Company notifies the employee, unless the employee must provide future service, in which case the benefits are expensed ratably over the future service period.

On March 16, 2020, in connection with entering into the Co-Promotion Agreement, the Company initiated a reduction in headcount, designed to eliminate the overlap with the Tetraphase commercial team in order to more efficiently commercialize DSUVIA alongside the Tetraphase commercial team and reduce operating expenses. The Company eliminated 30 positions, primarily within the commercial organization. For the year ended December 31, 2020, the Company incurred and paid $0.5 million in employee termination benefits related to this restructuring. The headcount reduction was completed in the first quarter of 2020. There were no such restructuring costs for the year ended December 31, 2021.

Interest Expense, Policy [Policy Text Block]

Non-Cash Interest Income (Expense) on Liability Related to Sale of Future Royalties

In September 2015, the Company sold certain royalty and milestone payment rights from the sales of Zalviso in the European Union by Grünenthal to PDL for gross proceeds of $65.0 million. Grünenthal terminated the Grünenthal Agreements effective November 13, 2020. The terms of the Grünenthal Agreements were extended to May 2021 to enable Grünenthal to sell down its Zalviso inventory. The rights to market and sell Zalviso in the Territory reverted back to the Company in May 2021.

Under the Royalty Monetization, the Company has a continuing obligation to use commercially reasonable efforts to negotiate a replacement license agreement, or New Arrangement. Under the relevant accounting guidance, because of the Company’s significant continuing involvement, the Royalty Monetization is accounted for as a liability that is being amortized using the effective interest method over the life of the arrangement. In order to determine the amortization of the liability, the Company is required to estimate the total amount of future royalty and milestone payments to be received by ARPI LLC and payments made to PDL, up to a capped amount of $195.0 million, over the life of the arrangement. The aggregate future estimated royalty and milestone payments (subject to the capped amount), less the $61.2 million of net proceeds the Company received, are amortized as interest expense over the life of the liability. Consequently, the Company imputes interest on the unamortized portion of the liability and records interest expense, or interest income, as these estimates are updated.

There are a number of factors that could materially affect the amount and timing of royalty and milestone payments from Zalviso in Europe, most of which are not within the Company’s control. Such factors include, but are not limited to, the success of any future sales and promotion of Zalviso under any New Arrangement, if achieved; changing standards of care; the introduction of competing products; manufacturing or other delays; intellectual property matters; adverse events that result in governmental health authority imposed restrictions on the use of Zalviso; significant changes in foreign exchange rates as the royalties remitted to ARPI LLC are made in U.S. dollars; and other events or circumstances that could result in reduced royalty payments from European sales of Zalviso, all of which may result in a reduction of non-cash royalty revenues and the non-cash interest expense over the life of the Royalty Monetization. Conversely, if sales of Zalviso in Europe are greater than expected, the non-cash royalty revenues and the non-cash interest expense recorded by the Company would be greater over the term of the Royalty Monetization. The Company periodically assesses the expected royalty and milestone payments using a combination of historical results, internal projections and forecasts from external sources. To the extent such payments are greater or less than the Company’s initial estimates or the timing of such payments is materially different than its original estimates, the Company will prospectively adjust the amortization of the liability and the effective interest rate. Because estimated sales forecasts and payments may vary over the life of the Royalty Monetization, the Company may be required to recognize interest income as the imputed interest rate is adjusted prospectively to reflect the revised effective interest rate over the term of the Royalty Monetization.

The Company records non-cash royalty revenues and non-cash interest income (expense), net, within its Consolidated Statements of Operations over the term of the Royalty Monetization.

When the expected payments under the Royalty Monetization are lower than the gross proceeds of $65.0 million received, the Company defers recognition of any probable contingent gain until the Royalty Monetization liability expires.

Comprehensive Income, Policy [Policy Text Block]

Comprehensive Loss

Comprehensive loss is comprised of net loss and other comprehensive income (loss) and is disclosed in the Consolidated Statements of Operations. For the Company, other comprehensive income (loss) consists of changes in unrealized gains and losses on the Company’s investments.

Income Tax, Policy [Policy Text Block]

Income Taxes

Deferred tax assets and liabilities are measured based on differences between the financial reporting and tax basis of assets and liabilities using enacted rates and laws that are expected to be in effect when the differences are expected to reverse. The Company records a valuation allowance for the full amount of deferred assets, which would otherwise be recorded for tax benefits relating to operating loss and tax credit carryforwards, as realization of such deferred tax assets cannot be determined to be more likely than not.

Earnings Per Share, Policy [Policy Text Block]

Net Loss per Share of Common Stock

The Company’s basic net loss per share of common stock is calculated by dividing the net loss by the weighted average number of shares of common stock outstanding for the period. The diluted net loss per share of common stock is computed by giving effect to all potential common stock equivalents outstanding for the period determined using the treasury stock method. For purposes of this calculation, convertible preferred stock, options to purchase common stock, restricted stock subject to repurchase, restricted stock units, warrants to purchase convertible preferred stock and warrants to purchase common stock were considered to be common stock equivalents. In periods with a reported net loss, such common stock equivalents are excluded from the calculation of diluted net loss per share of common stock if their effect is antidilutive. For additional information regarding the net loss per share, see Note 15 “Net Loss per Share of Common Stock”.

New Accounting Pronouncements, Policy [Policy Text Block]

Recently Adopted Accounting Standards

In December 2019, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2019-12, “Simplifying the Accounting for Income Taxes”. ASU 2019-12 eliminates certain exceptions related to the approach for intra-period tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. It also clarifies and simplifies other aspects of the accounting for income taxes. ASU 2019-12 is effective for fiscal years beginning after December 15, 2020, and interim periods within those fiscal years. The Company adopted ASU 2019-12 on January 1, 2021, which did not have a material impact on the Company’s Consolidated Financial Statements.

In August 2020, the FASB issued ASU 2020-06, “Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity's Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity's Own Equity”. The standard simplifies accounting for convertible instruments by removing major separation models required under current GAAP. Consequently, more convertible debt instruments will be reported as a single liability instrument with no separate accounting for embedded conversion features. ASU 2020-06 removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception, which will permit more equity contracts to qualify for it. The standard also simplifies the diluted net income per share calculation in certain areas. ASU 2020-06 is effective for fiscal years beginning after December 15, 2023, and interim periods within those fiscal years for smaller reporting companies, with early adoption permitted. The Company early adopted ASU 2020-06 on January 1, 2021, which did not have a material impact on the Company’s Consolidated Financial Statements on the date of adoption.

Recently Issued Accounting Pronouncements

In June 2016, the FASB issued ASU 2016-13, “Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments,” or ASU 2016-13. ASU 2016-13 replaces the incurred loss impairment model in current GAAP with a model that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to determine credit loss estimates. ASU 2016-13 is effective for the Company beginning January 1, 2023, with early adoption allowed beginning January 1, 2020. In May 2019, the FASB issued ASU 2019-05, “Financial Instruments – Credit Losses,” or ASU 2019-05, to allow entities to irrevocably elect the fair value option for certain financial assets previously measured at amortized cost upon adoption of the new credit losses standard. The new effective dates and transition align with those of ASU 2016-13. Management is currently assessing the date of adoption and the impact ASU 2016-13 and ASU 2019-05 will have on the Company, but it does not anticipate adoption of these new standards to have a material impact on the Company’s financial position, results of operations or cash flows.

In March 2020, the FASB issued ASU 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting,” which provides elective amendments for entities that have contracts, hedging relationships and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. These amendments are effective immediately and may be applied prospectively to contract modifications made and hedging relationships entered into or evaluated on or before December 31, 2022. In January 2021, the FASB issued ASU 2021-01, “Reference Rate Reform (Topic 848),” to expand and clarify the scope of Topic 848 to include derivative instruments on discounting transactions. The amendments in this ASU are effective in the same timeframe as ASU 2020-04. The Company is currently evaluating the impact this guidance will have on its Consolidated Financial Statements.

Note 1 - Organization and Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2021

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

	Year Ended December 31,
Percent of Total Revenue	2021			2020
Aguettant		61.9	%		0	%
Grünenthal		11.7	%		74.0	%
DoD		0.3	%		16.9	%
Wholesaler A		15.9	%		3.9	%

	As of December 31,
Percent of Accounts Receivable, Net	2021			2020
Customer A		73	%		12	%
Customer B		0	%		79	%

Note 2 - Investments and Fair Value Measurement (Tables)

12 Months Ended

Dec. 31, 2021

Cash, Cash Equivalents and Investments [Table Text Block]

	As of December 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Cash and cash equivalents:
Cash	$	1,443	$	—	$	—	$	1,443
Money market funds		2,822		—		—		2,822
Commercial paper		8,398		—		—		8,398
Total cash and cash equivalents		12,663		—		—		12,663

Short-term investments:
Commercial paper		29,504		—		—		29,504
Corporate debt securities		9,463		—		—		9,463
Total short-term investments		38,967		—		—		38,967
Total cash, cash equivalents and short-term investments	$	51,630	$	—	$	—	$	51,630

	As of December 31, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Cash and cash equivalents:
Cash	$	5,181	$	—	$	—	$	5,181
Money market funds		3,996		—		—		3,996
Commercial paper		18,097		—		—		18,097
Total cash and cash equivalents		27,274		—		—		27,274

Short-term investments:
U.S. government agency securities		5,818		—		—		5,818
Commercial paper		9,794		—		—		9,794
Total short-term investments		15,612		—		—		15,612
Total cash, cash equivalents and short-term investments	$	42,886	$	—	$	—	$	42,886

Fair Value Measurements, Recurring and Nonrecurring [Table Text Block]

	As of December 31, 2021
	Fair Value		Level I		Level II		Level III
Assets
Money market funds	$	2,822	$	2,822	$	—	$	—
Commercial paper		37,902		—		37,902		—
Corporate debt securities		9,463		—		9,463		—
Total assets measured at fair value	$	50,187	$	2,822	$	47,365	$	—

Liabilities
Contingent put option liability	$	81	$	—	$	—	$	81
Total liabilities measured at fair value	$	81	$	—	$	—	$	81

	As of December 31, 2020
	Fair Value		Level I		Level II		Level III
Assets
Money market funds	$	3,996	$	3,996	$	—	$	—
U.S. government agency securities		5,818		—		5,818		—
Commercial paper		27,891		—		27,891		—
Total assets measured at fair value	$	37,705	$	3,996	$	33,709	$	—

Liabilities
Contingent put option liability	$	246	$	—	$	—	$	246
Total liabilities measured at fair value	$	246	$	—	$	—	$	246

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

	Year Ended December 31, 2021
Fair value—beginning of period	$	246
Change in fair value of contingent put option associated with the Loan Agreement		(165	)
Fair value—end of period	$	81

	Year Ended December 31, 2020
Fair value—beginning of period	$	437
Change in fair value of contingent put option associated with the Loan Agreement		(191	)
Fair value—end of period	$	246

Tabular disclosure of financial instruments measured at fair value, including those classified in shareholders' equity measured on a recurring or nonrecurring basis. Disclosures include, but are not limited to, fair value measurements recorded and the reasons for the measurements, level within the fair value hierarchy in which the fair value measurements are categorized and transfers between levels 1 and 2. Nonrecurring fair value measurements are those that are required or permitted in the statement of financial position in particular circumstances.

+ References + Details

Note 3 - Inventories, Net (Tables)

12 Months Ended

Dec. 31, 2021

Schedule of Inventory, Current [Table Text Block]

	As of December 31,
	2021		2020
Raw materials	$	722	$	257
Work-in-process		159		30
Finished goods		230		1,339
Inventories	$	1,111	$	1,626

Note 4 - Property and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment [Table Text Block]

	As of December 31,
	2021			2020
Laboratory equipment	$	4,406		$	4,406
Leasehold improvements		5,838			4,616
Computer equipment and software		1,589			1,724
Construction in process		13,805			14,101
Tooling		826			1,109
Furniture and fixtures		250			292
		26,714			26,248
Less accumulated depreciation and amortization		(10,786	)		(10,589	)
Property and equipment, net	$	15,928		$	15,659

Note 7 - Revenue From Contracts With Customers (Tables)

12 Months Ended

Dec. 31, 2021

Disaggregation of Revenue [Table Text Block]

	December 31,
	2021		2020
Product sales:
DSUVIA	$	735	$	1,409
Zalviso		270		1,112
Total product sales		1,005		2,521
Contract and other collaboration:
License revenue		1,696		—
Non-cash royalty revenue related to Royalty Monetization (See Note 10)		83		242
Royalty revenue		28		81
Other revenue		6		2,572
Total revenues from contract and other collaboration		1,813		2,895
Total revenue	$	2,818	$	5,416

Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]

Balance at January 1, 2020	$	3,244
Deductions for performance obligations satisfied:
In current period		( 623	)
In prior periods⁽¹⁾		(2,572	)
Balance at December 31, 2020	$	49
Additions⁽²⁾		1,237
Deductions for performance obligations satisfied:
In current period		(49	)
Balance at December 31, 2021	$	1,237

Note 8 - Long-term Debt (Tables)

12 Months Ended

Dec. 31, 2021

Schedule of Maturities of Long-term Debt [Table Text Block]

2022	$	9,647
2023		5,530
Total payments		15,177
Less amount representing interest		(927	)
Notes payable, gross		14,250
Less: Unamortized portion of EOT Fee		(200	)
Less: Unamortized discount on notes payable		(247	)
Long-term debt		13,803
Less current portion		(8,796	)
Long-term debt, net of current portion	$	5,007

Note 9 - Leases (Tables)

12 Months Ended

Dec. 31, 2021

Lease, Cost [Table Text Block]

	Year ended December 31, 2021			Year ended December 31, 2020
Operating lease costs	$	1,467		$	1,360
Gain on derecognition of operating lease		(522	)		—
Sublease income		(199	)		(598	)
Loss on termination of sublease		331			—
Net lease costs	$	1,077		$	762

	December 31,			December 31,
	2021			2020
Weighted-average remaining lease term – operating leases (in years)	4.97			3.1
Weighted-average remaining discount rate – operating leases (in years)		12.8	%		11.7	%

Lessee, Operating Lease, Liability, Maturity [Table Text Block]

Year:
2022	$	1,608
2023		1,244
2024		1,040
2025		1,040
2026		1,040
Thereafter		415
Total future minimum lease payments		6,387
Less imputed interest		(1,569	)
Total	$	4,818

Operating lease liabilities	$	4,818
Operating lease liabilities, current portion		(1,068	)
Operating lease liabilities, net of current portion	$	3,750

Note 10 - Liability Related to Sale of Future Royalties (Tables)

12 Months Ended

Dec. 31, 2021

Other Liabilities [Table Text Block]

	Year ended December 31, 2021			Period from inception to December 31, 2021
Liability related to sale of future royalties — beginning balance	$	88,471		$	—
Proceeds from sale of future royalties		—			61,184
Non-cash royalty revenue		(145	)		(1,083	)
Non-cash interest (income) expense recognized		(3,038	)		25,187
Liability related to sale of future royalties as of December 31, 2021	$	85,288		$	85,288

Note 14 - Stock Based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	December 31, 2021		December 31, 2020
Cost of goods sold	$	92	$	123
Research and development		813		764
Selling, general and administrative		3,704		3,537
Total	$	4,609	$	4,424

Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]

				Weighted
	Number of			*Average*
	*Restricted*			Grant Date
	Stock Units			Fair Value
Restricted stock units outstanding, January 1, 2020		988,645		$	2.53
Granted		908,300			1.30
Vested		(304,810	)		2.53
Forfeited		(194,152	)		2.16
Restricted stock units outstanding, December 31, 2020		1,397,983		$	1.79
Granted		1,149,632			1.68
Vested		(587,214	)		1.89
Forfeited		(186,025	)		1.58
Restricted stock units outstanding, December 31, 2021		1,774,376		$	1.71

Share-based Payment Arrangement, Option, Activity [Table Text Block]

	Number of Stock Options Outstanding			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value
								(in thousands)
December 31, 2020		12,813,022		$	3.20
Granted		2,667,612			1.82
Forfeited		(375,432	)		1.79
Expired		(801,749	)		3.03
Exercised		(19,403	)		0.84
December 31, 2021		14,284,050		$	2.99		5.8	$	—
Vested and exercisable options—December 31, 2021		10,496,744		$	3.42		4.8	$	—
Vested and expected to vest—December 31, 2021		14,284,050		$	2.99		5.8	$	—

Schedule of Share-based Compensation, Stock Options Outstanding and Exercisable Activity [Table Text Block]

			Options Outstanding						Options Vested and Exercisable
Exercise Prices			Number of Stock Options Outstanding		Weighted-Average Remaining Contractual Life (Years)		Weighted-Average Exercise Price per Share		Shares Subject to Stock Options		Weighted-Average Exercise Price per Share
$0.72	-	$1.12		695,482		8.1	$	0.85		280,047	$	0.84
$1.26	-	$1.89		3,402,418		8.9	$	1.80		496,679	$	1.67
$2.00	-	$3.00		5,310,550		6.1	$	2.44		4,856,618	$	2.43
$3.10	-	$4.65		3,066,819		3.8	$	3.37		3,054,619	$	3.38
$4.73	-	$7.10		1,295,781		1.8	$	5.71		1,295,781	$	5.71
$8.18	-	$12.27		513,000		2.1	$	10.28		513,000	$	10.28
				14,284,050		5.8	$	2.99		10,496,744	$	3.42

Time-based Stock Option [Member]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Year Ended December 31,
	2021				2020
Expected term (in years)		6.0	-	6.2			6.2
Risk-free interest rate		0.9%	-	1.3%		0.4%	-	1.5%
Expected volatility			90%				83%
Expected dividend rate			0%				0%

Performance Shares [Member]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Year Ended December 31,
	2021			2020
Derived service period (in years)	2.3	–	2.6		—
Risk-free interest rate		1.5%			—
Expected volatility		90%			—
Expected dividend rate		0%			—

Note 15 - Net Loss Per Share of Common Stock (Tables)

12 Months Ended

Dec. 31, 2021

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	Year Ended December 31,
	2021		2020
ESPP, RSUs and stock options to purchase common stock		16,328,426		14,541,005
Common stock warrants		17,676,679		176,679

Note 16 - Accrued Liabilities (Tables)

12 Months Ended

Dec. 31, 2021

Schedule of Accrued Liabilities [Table Text Block]

	December 31,
	2021		2020
Accrued compensation and employee benefits	$	2,974	$	3,323
Accrued professional services		1,523		179
Accrued product returns and sales allowances		775		656
Deferred revenue		86		49
Other accrued liabilities		1,166		838
Total accrued liabilities	$	6,524	$	5,045

Note 18 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Schedule of Deferred Tax Assets [Table Text Block]

	December 31, 2021			December 31, 2020
Deferred tax assets:
Accruals and other	$	3,989		$	4,136
Research credits		7,275			7,275
Net operating loss carryforward		75,452			65,274
Section 59(e) R&D expenditures		5,070			7,473
Deferred revenue		19,666			20,848
Total deferred tax assets		111,452			105,006
Valuation allowance		(111,452	)		(105,006	)
Net deferred tax assets	$	—		$	—

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	Year Ended December 31,
	2021			2020
Tax at statutory federal rate	$	(7,370	)	$	(8,486	)
State tax—net of federal benefit		231			(3,587	)
Stock options		718			636
Other		(20	)		—
Change in valuation allowance		6,446			11,441
Provision for income taxes	$	5		$	4

Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]

	Year Ended December 31,
	2021		2020
Unrecognized benefit—beginning of period	$	2,635	$	2,635
Gross increases—prior period tax positions		—		—
Gross increases—current period tax positions		—		—
Unrecognized benefit—end of period	$	2,635	$	2,635

Schedule II - Valuation and Qualifying Accounts (Tables)

12 Months Ended

Dec. 31, 2021

Valuation Allowances and Reserves [Table Text Block]

SCHEDULE II: VALUATION AND QUALIFYING ACCOUNTS
(in thousands)


			*Additions*
	*Balance at*		*Charged as a*					*Balance at*
	*Beginning of*		*Reduction to*					*End of*
Description	*Period*		*Revenue*		Deductions*			*Period*
Sales & return allowances, discounts, chargebacks and rebates:
Year ended December 31, 2021	$	668	$	1,012	$	(900	)	$	780
Year ended December 31, 2020	$	161	$	645	$	(138	)	$	668

* Deductions to sales discounts and allowances relate to discounts or allowances actually taken or paid.

Note 1 - Organization and Summary of Significant Accounting Policies (Details Textual) $ in Thousands			1 Months Ended	12 Months Ended		75 Months Ended
	Mar. 16, 2020	Sep. 18, 2015 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2021 USD ($)
Cash, Cash Equivalents, and Short-term Investments, Total				$ 51,630	$ 42,886	$ 51,630
Restructuring and Related Cost, Number of Positions Eliminated	30
Restructuring Charges, Total					$ 500
Proceeds From Sale of Royalty and Milestone Rights		$ 65,000	$ 65,000
Royalty Arrangment Maximum Payments		195,000	195,000
Net Proceeds from Sale of Future Royalties		$ 61,200	$ 61,200	$ 0		$ 61,184
Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)				3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)				5 years

Note 1 - Organization and Summary of Significant Accounting Policies - Concentration of Revenue and Accounts Receivable (Details) - Customer Concentration Risk [Member]	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Revenue Benchmark [Member] \| Aguettant [Member]
Concentration risk	61.90%	0.00%
Revenue Benchmark [Member] \| Grunenthal [Member]
Concentration risk	11.70%	74.00%
Revenue Benchmark [Member] \| DoD [Member]
Concentration risk	0.30%	16.90%
Revenue Benchmark [Member] \| Wholesaler A [Member]
Concentration risk	15.90%	3.90%
Accounts Receivable [Member] \| Customer A [Member]
Concentration risk	73.00%	12.00%
Accounts Receivable [Member] \| Customer B [Member]
Concentration risk	0.00%	79.00%

Note 2 - Investments and Fair Value Measurement (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale, Realized Gain (Loss), Total	$ 0	$ 0	$ 0
Debt Securities, Available-for-sale, Total	0
OCI, Debt Securities, Available-for-Sale, Transfer from Held-to-Maturity, Gain (Loss), before Adjustment, after Tax	$ 0	0
Other-than-temporary Impairment Loss, Debt Securities, Available-for-sale, Total		$ 0

Note 2 - Investments and Fair Value Measurement - Summary of Cash, Cash Equivalents and Investments (Details) - USD ($)
$ in Thousands

Dec. 31, 2021

Dec. 31, 2020

$ 0

Cash and cash equivalents

12,663

27,274

^[1]

Total cash, cash equivalents and short-term investments

51,630

42,886

Total cash, cash equivalents and short-term investments, fair value

51,630

42,886

Cash and Cash Equivalents [Member]

Cash and cash equivalents

12,663

27,274

12,663

27,274

Cash and Cash Equivalents [Member] | Cash [Member]

Cash, amortized cost

1,443

5,181

Cash and Cash Equivalents [Member] | Money Market Funds [Member]

1,443

5,181

Money market funds, amortized cost

2,822

3,996

2,822

3,996

Cash and Cash Equivalents [Member] | Commercial Paper [Member]

18,097

8,398

Marketable Securities [Member]

8,398

Commercial paper

18,097

38,967

15,612

Marketable Securities [Member] | Commercial Paper [Member]

38,967

15,612

29,504

9,794

Marketable Securities [Member] | US Government Agencies Debt Securities [Member]

29,504

9,794

5,818

Marketable Securities [Member] | Corporate Debt Securities [Member]

$ 5,818

9,463

$ 9,463

[1]	The condensed consolidated balance sheet as of December 31, 2020 has been derived from the audited financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020.

Note 2 - Investments and Fair Value Measurement - Fair Value of Financial Assets and Liabilities by Level Within Fair Value Hierarchy (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets, fair value	$ 50,187	$ 37,705
Liabilities, fair value	81	246
Contingent Put Option Liability [Member]
Liabilities, fair value	81	246
Fair Value, Inputs, Level 1 [Member]
Assets, fair value	2,822	3,996
Liabilities, fair value	0	0
Fair Value, Inputs, Level 1 [Member] \| Contingent Put Option Liability [Member]
Liabilities, fair value	0	0
Fair Value, Inputs, Level 2 [Member]
Assets, fair value	47,365	33,709
Liabilities, fair value	0	0
Fair Value, Inputs, Level 2 [Member] \| Contingent Put Option Liability [Member]
Liabilities, fair value	0	0
Fair Value, Inputs, Level 3 [Member]
Assets, fair value	0	0
Liabilities, fair value	81	246
Fair Value, Inputs, Level 3 [Member] \| Contingent Put Option Liability [Member]
Liabilities, fair value	81	246
Money Market Funds [Member]
Assets, fair value	2,822	3,996
Money Market Funds [Member] \| Fair Value, Inputs, Level 1 [Member]
Assets, fair value	2,822	3,996
Money Market Funds [Member] \| Fair Value, Inputs, Level 2 [Member]
Assets, fair value	0	0
Money Market Funds [Member] \| Fair Value, Inputs, Level 3 [Member]
Assets, fair value	0	0
Commercial Paper [Member]
Assets, fair value	37,902	27,891
Commercial Paper [Member] \| Fair Value, Inputs, Level 1 [Member]
Assets, fair value	0	0
Commercial Paper [Member] \| Fair Value, Inputs, Level 2 [Member]
Assets, fair value	37,902	27,891
Commercial Paper [Member] \| Fair Value, Inputs, Level 3 [Member]
Assets, fair value	0	0
U.S. Government Agency Securities [Member]
Assets, fair value		5,818
U.S. Government Agency Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Assets, fair value		0
U.S. Government Agency Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Assets, fair value		5,818
U.S. Government Agency Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Assets, fair value		$ 0
Corporate Debt Securities [Member]
Assets, fair value	9,463
Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Assets, fair value	0
Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Assets, fair value	9,463
Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Assets, fair value	$ 0

Note 2 - Investments and Fair Value Measurement - Summary of Changes in Fair Value of Level III Financial Liabilities (Details) - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Fair value, Beginning of period	$ 246	$ 437
Change in fair value of contingent put option associated with the Loan Agreement	(165)
Change in fair value of contingent put option associated with the Loan Agreement		(191)
Fair value, End of period	$ 81	$ 246

Note 3 - Inventories, Net (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Inventory Write-down	$ 810	$ 712
Amended License Agreement [Member]
Inventory Write-down		300
DSUVIA [Member]
Inventory Write-down		$ 400

Note 3 - Inventories, Net - Inventory Components (Details) - USD ($)
$ in Thousands

Dec. 31, 2021

Dec. 31, 2020

Raw materials

$ 722

$ 257

Work-in-process

159

Finished goods

230

1,339

Inventories

$ 1,111

$ 1,626

^[1]

[1]	The condensed consolidated balance sheet as of December 31, 2020 has been derived from the audited financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020.

Note 4 - Property and Equipment, Net (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Depreciation, Total	$ 1.1	$ 1.1

Note 4 - Property and Equipment, Net - Components of Property and Equipment (Details) - USD ($)
$ in Thousands

Dec. 31, 2021

Dec. 31, 2020

Less accumulated depreciation and amortization

$ 26,714

$ 26,248

(10,786)

(10,589)

Property and equipment, net

15,928

15,659

^[1]

Laboratory Equipment [Member]

Leasehold Improvements [Member]

4,406

Computer Equipment and Software [Member]

5,838

4,616

Construction in Progress [Member]

1,589

1,724

13,805

14,101

Tooling [Member]

Furniture and Fixtures [Member]

826

1,109

$ 250

$ 292

[1]	The condensed consolidated balance sheet as of December 31, 2020 has been derived from the audited financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020.

Note 5 - In-license Agreement (Details Textual) - Aguettant [Member] - PFS Products [Member] $ in Millions	Jul. 14, 2021 USD ($)
License Agreement, Term (Year)	10 years
License Agreement, Renewal Term (Year)	5 years
License Agreement, Milestone Payments to be Paid, Maximum	$ 24
License Agreement, Minimum Sales Obligation Term (Month)	12 months
Minimum [Member]
License Agreement, Percent of Revenue Share Payment to be Paid	40.00%
Maximum [Member]
License Agreement, Percent of Revenue Share Payment to be Paid	45.00%

Note 6 - Out-license Agreements (Details Textual) $ in Thousands, € in Millions		1 Months Ended	3 Months Ended		12 Months Ended
	Jul. 14, 2021 EUR (€)	Jul. 31, 2021	Sep. 30, 2021 USD ($)	Sep. 30, 2021 EUR (€)	Dec. 31, 2021 USD ($)	Dec. 31, 2021 EUR (€)	Dec. 31, 2020 USD ($)	Jul. 17, 2015 USD ($)
Revenue from Contract with Customer, Including Assessed Tax					$ 2,818		$ 5,416
Amended License Agreement [Member]
Revenue Recognition Milestone Method Agreed, Additional Amount, Based On Efforts And Targets								$ 194,500
Amended License Agreement [Member] \| Based upon Successful Regulatory and Product Development Efforts [Member]
Revenue Recognition Milestone Method Agreed, Additional Amount, Based On Efforts And Targets								28,500
Amended License Agreement [Member] \| Based upon Net Sales Target Achievements [Member]
Revenue Recognition Milestone Method Agreed, Additional Amount, Based On Efforts And Targets								$ 166,000
Aguettant [Member] \| DZUVEO [Member]
License Agreement, Renewal Term (Year)	5 years	5 years
License Agreement, Upfront and Maximum Milestone Payments to be Received \| €	€ 47.0
Proceeds form Up-front and Sales-based Milestone License Payments			$ 2,900	€ 2.5	2,900	€ 2.5
Revenue from Contract with Customer, Including Assessed Tax			$ 1,700		$ 1,700
Aguettant [Member] \| DZUVEO [Member] \| Minimum [Member]
License Agreement, Percent of Revenue Share Payments to be Received	35.00%
Aguettant [Member] \| DZUVEO [Member] \| Maximum [Member]
License Agreement, Percent of Revenue Share Payments to be Received	45.00%

Note 7 - Revenue From Contracts With Customers (Details Textual) $ in Thousands, € in Millions		1 Months Ended		3 Months Ended		12 Months Ended
	Jul. 14, 2021	Jul. 31, 2021	May 31, 2020 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2021 EUR (€)	Dec. 31, 2021 USD ($)	Dec. 31, 2021 EUR (€)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Revenue from Contract with Customer, Including Assessed Tax						$ 2,818		$ 5,416
Contract with Customer, Liability, Total						1,237		49	$ 3,244
DZUVEO [Member] \| Aguettant [Member]
Proceeds form Up-front and Sales-based Milestone License Payments				$ 2,900	€ 2.5	2,900	€ 2.5
License Agreement, Milestone Payments and Revenue Share Payments to be Received						52,200
License Agreement, Term (Year)		10 years
License Agreement, Renewal Term (Year)	5 years	5 years
Revenue from Contract with Customer, Including Assessed Tax				$ 1,700		1,700
Contract with Customer, Liability, Total						1,200
Contract with Customer, Liability, Current						100
Capitalized Contract Cost, Amortization						300
ZALVISO [Member]
Revenue from Contract with Customer, Including Assessed Tax						$ 270		$ 1,112
Contract with Customer, Liability, Liability Eliminated			$ 2,600

Note 7 - Revenue From Contracts With Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Revenue	$ 2,818	$ 5,416
DSUVIA [Member]
Revenue	735	1,409
ZALVISO [Member]
Revenue	270	1,112
Product [Member]
Revenue	1,005	2,521
License [Member]
Revenue	1,696	0
Non-cash Royalty [Member]
Revenue	83	242
Royalty [Member]
Revenue	28	81
Contract and Other Revenue [Member]
Revenue	6	2,572
Contract and Other Collaboration [Member]
Revenue	$ 1,813	$ 2,895

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 41
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9038-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130545-203045

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9054-108599

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 40
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9031-108599

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 924
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-URI http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856

Note 7 - Revenue From Contracts With Customers - Contract Liability (Details) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2021

Dec. 31, 2020

$ 49

$ 3,244

In current period

(49)

(623)

In prior periods(1)

^[1]

(2,572)

Additions(2)

^[2]

1,237

Less amount representing interest

$ 1,237

$ 49

[1]	In May 2020, upon notification of early termination by Grünenthal, the Company recognized approximately $2.6 million of deferred revenue under the Grünenthal Agreements.
[2]	Deferred revenue under the DZUVEO Agreement with Aguettant.

Note 8 - Long-term Debt (Details Textual) - USD ($)			12 Months Ended
Note 8 - Long-term Debt (Details Textual) - USD ($)	Aug. 01, 2019	May 30, 2019	Dec. 31, 2021	Dec. 31, 2020
Repayments of Long-term Debt, Total			$ 8,833,000	$ 4,667,000
Long-term Debt, Total			13,803,000
Amortization of Debt Discount (Premium)			761,000	$ 1,069,000
Leasehold Improvements, Gross			$ 1,700,000
Site Readiness Agreement [Member]
Debt Instrument, Interest Rate, Effective Percentage			14.35%	14.35%
Debt Instrument, Periodic Payment, Principal	$ 500,000
Total Obligation Under Leasehold Agreement			$ 500,000	$ 800,000
Warrant In Connection with Oxford Finance Loan Agreement [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		176,679
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		$ 2.83
Loan Agreement with Oxford Finance LLC [Member]
Debt Instrument, Face Amount		$ 25,000,000.0
Repayments of Long-term Debt, Total		8,900,000
Proceeds from Debt, Net of Issuance Costs and Repayment of Debt		$ 15,900,000
Debt Instrument, Interest Rate, Base Percentage		2.50%
Prepayment Charge, Percentage of Outstanding Balance, After May 30, 2020, Before May 30, 2021		1.00%
Debt Instrument, Covenant, Minimum Required Unrestircted Cash		$ 5,000,000.0
Debt Instrument, Minimum Indebtedness Amount with Acceleration Right		250,000
Loan Default Events, Trigger of Negative Impact of Government Approvals and Judgments		$ 500,000
Debt Instrument, Default Additional Interest Rate		5.00%
Fair Value of Contingent Put Option, Liability			100,000
Long-term Debt, Total			13,300,000	21,000,000.0
Interest Expense, Debt, Total			2,200,000	3,200,000
Amortization of Debt Discount (Premium)			$ 700,000	$ 900,000
Debt Instrument, Interest Rate, Effective Percentage			13.15%	13.15%
Loan Agreement with Oxford Finance LLC [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate		6.75%

Note 8 - Long-term Debt - Outstanding Future Payments of Long-term Debt (Details) - USD ($)
$ in Thousands

Dec. 31, 2021

Dec. 31, 2020

^[1]

2022

$ 9,647

2023

5,530

Total payments

15,177

(927)

Notes payable, gross

14,250

Less: Unamortized portion of EOT Fee

(200)

Less: Unamortized discount on notes payable

(247)

Long-term debt

13,803

Less current portion

(8,796)

$ (8,735)

Long-term debt, net of current portion

$ 5,007

$ 13,140

[1]	The condensed consolidated balance sheet as of December 31, 2020 has been derived from the audited financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020.

Note 9 - Leases (Details Textual)

12 Months Ended

Mar. 26, 2021

USD ($)

Dec. 12, 2012

USD ($)

Dec. 31, 2022

USD ($)

Dec. 31, 2021

USD ($)

ft²

Dec. 31, 2020

USD ($)

Apr. 30, 2021

USD ($)

Apr. 21, 2021

Gain (Loss) on Termination of Lease

$ 500,000

$ 522,000

$ (0)

Operating Lease, Right-of-Use Asset

$ 4,302,000

$ 3,150,000

^[1]

Lessee, Operating Lease, Renewal Term (Year)

2 years

Lessee, Operating Lease, Notice Period (Year)

18 years

Lessee, Operating Lease, Annual Overhead Fee Payments

$ 200,000

Catalent Pharma Solutions [Member]

Lessee, Operating Lease, Term of Contract (Year)

5 years

Lessee, Operating Lease, Renewal Term (Year)

2 years

Catalent Pharma Solutions [Member] | Forecast [Member]

Operating Lease, Expense

$ 1,000,000.0

Prepaid Expenses and Other Current Assets [Member]

Lessee, Operating Sublease, Deferred Costs

$ 300,000

Lease for Corporate Headquarters in Hayward, California [Member]

Area of Real Estate Property (Square Foot) | ft²

12,106

Lessee, Operating Lease, Term of Contract (Year)

2 years 3 months

Lessee, Operating Lease, Monthly Rent

$ 17,000

Lessee, Operating Lease, Abated Rent Period (Month)

1 month

Operating Lease, Right-of-Use Asset

$ 400,000

[1]	The condensed consolidated balance sheet as of December 31, 2020 has been derived from the audited financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020.

Note 9 - Leases - Operating Lease Costs (Details) - USD ($) $ in Thousands		12 Months Ended
	Mar. 26, 2021	Dec. 31, 2021	Dec. 31, 2020
Operating lease costs		$ 1,467	$ 1,360
Gain on derecognition of operating lease	$ (500)	(522)	0
Sublease income		(199)	(598)
Loss on termination of sublease		331	0
Net lease costs		$ 1,077	$ 762
Weighted-average remaining lease term – operating leases (in years) (Year)		4 years 11 months 19 days	3 years 1 month 6 days
Weighted-average remaining discount rate – operating leases (in years)		12.80%	11.70%

Note 9 - Leases - Maturities of Lease Liabilities (Details) - USD ($)
$ in Thousands

Dec. 31, 2021

Dec. 31, 2020

^[1]

$ 1,608

1,244

1,040

1,040

1,040

415

Total future minimum lease payments

6,387

Less imputed interest

(1,569)

Total

4,818

Operating lease liabilities

4,818

Operating lease liabilities, current portion

(1,068)

$ (1,118)

Operating lease liabilities, net of current portion

$ 3,750

$ 2,606

[1]	The condensed consolidated balance sheet as of December 31, 2020 has been derived from the audited financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020.

Note 10 - Liability Related to Sale of Future Royalties (Details Textual) - USD ($) $ in Thousands		1 Months Ended	12 Months Ended		75 Months Ended
	Sep. 18, 2015	Sep. 30, 2015	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021
Proceeds From Sale of Royalty and Milestone Rights	$ 65,000	$ 65,000
Percentage of Royalties and Rights Under Agreement	75.00%
Royalty Arrangment Maximum Payments	$ 195,000	195,000
Net Proceeds from Sale of Future Royalties	$ 61,200	$ 61,200	$ 0		$ 61,184
Contingent Gain (Loss) on Royalty Monetization Arrangement			$ 64,000
Effective Interest Over Life of Liability Related to Sale of Future Royalties			0.00%
Effective Annual Interest Rate			3.50%	3.60%
First Four Commercial Milestones [Member]
Percentage of Royalties and Rights Under Agreement	80.00%
Commercial Milestones Value Maximum Amount Available	$ 44,500

Note 10 - Liability Related to Sale of Future Royalties - Activity of Liability Related to Sale of Future Royalties (Details) - USD ($) $ in Thousands		1 Months Ended	12 Months Ended		75 Months Ended
	Sep. 18, 2015	Sep. 30, 2015	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021
Liability related to sale of future royalties — beginning balance			$ 88,471		$ 0
Proceeds from sale of future royalties	$ 61,200	$ 61,200	0		61,184
Non-cash royalty revenue			(145)		(1,083)
Non-cash interest (income) expense recognized			(3,038)	$ (3,310)	25,187
Liability related to sale of future royalties as of December 31, 2021			$ 85,288		$ 85,288

Note 11 - Warrants (Details Textual)			12 Months Ended
Note 11 - Warrants (Details Textual)	Nov. 17, 2021 USD ($) $ / shares shares	Nov. 15, 2021 USD ($) $ / shares shares	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($) shares	May 30, 2019 USD ($) $ / shares yr shares
Stock Issued During Period, Value, New Issues			$ 44,716,000	$ 21,337,000
Proceeds from Issuance of Common Stock			44,716,000	21,337,000
Proceeds from Issuance of Warrants			$ 5,562,000	$ 0
2021 Registered Direct Offering [Member]
Stock Issued During Period, Value, New Issues	$ 13,100,000
Proceeds from Issuance or Sale of Equity, Total	$ 14,000,000.0	$ 14,000,000.0
2021 Registered Direct Offering [Member] \| Measurement Input, Risk Free Interest Rate [Member]
Proceeds from Issuance or Sale of Equity, Total		14,000,000.0
Proceeds from Issuance of Common Stock		$ 8,400,000
November 2021 Financing Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) \| shares		17,500,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) \| $ / shares	$ 1.00	$ 1.00
Warrants and Rights Outstanding	$ 5,600,000	$ 8,600,000
Proceeds from Issuance of Warrants		$ 5,600,000
November 2021 Financing Warrants [Member] \| Measurement Input, Share Price [Member]
Warrants and Rights Outstanding, Measurement Input		0.7461
November 2021 Financing Warrants [Member] \| Measurement Input, Expected Term [Member]
Warrants and Rights Outstanding, Measurement Input		5
November 2021 Financing Warrants [Member] \| Measurement Input, Price Volatility [Member]
Warrants and Rights Outstanding, Measurement Input		0.9177
November 2021 Financing Warrants [Member] \| Measurement Input, Risk Free Interest Rate [Member]
Warrants and Rights Outstanding, Measurement Input		0.0126
November 2021 Financing Warrants [Member] \| Maximum [Member]
Class of Warrant or Right, Required Percentage of Ownership to Become Exercisable		9.99%
November 2021 Financing Warrants [Member] \| 2021 Registered Direct Offering [Member]
Stock Issued During Period, Value, New Issues		$ 17,500,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) \| shares	17,500,000
Warrant In Connection with Oxford Finance Loan Agreement [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) \| shares					176,679
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) \| $ / shares					$ 2.83
Warrants and Rights Outstanding					$ 400,000
Warrants and Rights Outstanding, Term (Year)					10 years
Class of Warrant or Right, Outstanding (in shares) \| shares				176,679
Warrant In Connection with Oxford Finance Loan Agreement [Member] \| Measurement Input, Share Price [Member]
Warrants and Rights Outstanding, Measurement Input \| $ / shares					2.66
Warrant In Connection with Oxford Finance Loan Agreement [Member] \| Measurement Input, Expected Term [Member]
Warrants and Rights Outstanding, Measurement Input \| yr					10
Warrant In Connection with Oxford Finance Loan Agreement [Member] \| Measurement Input, Price Volatility [Member]
Warrants and Rights Outstanding, Measurement Input					0.8022
Warrant In Connection with Oxford Finance Loan Agreement [Member] \| Measurement Input, Risk Free Interest Rate [Member]
Warrants and Rights Outstanding, Measurement Input					0.0222
Warrant In Connection with Oxford Finance Loan Agreement [Member] \| Measurement Input, Exercise Price [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) \| $ / shares					$ 2.83
Warrant In Connection with Oxford Finance Loan Agreement [Member] \| Measurement Input, Expected Dividend Rate [Member]
Warrants and Rights Outstanding, Measurement Input					0

Note 12 - Commitments and Contingencies (Details Textual)	Jul. 06, 2021	Jun. 08, 2021
Purported Shareholder v. Company - Violation of Sections 10(b) and 20(a) of the Exchange Act and SEC Rule 10b-5 [Member]
Loss Contingency, Number of Defendants		2
Purported Shareholder v. Company - Alleged Misstatements as the Shareholder [Member]
Loss Contingency, Number of Defendants	10

Note 13 - Stockholders' Equity (Details Textual) - USD ($)

1 Months Ended

12 Months Ended

Nov. 17, 2021

Nov. 15, 2021

Jun. 17, 2021

Jan. 27, 2021

Jan. 22, 2021

Dec. 11, 2020

Jul. 23, 2020

May 09, 2019

Jun. 21, 2016

Jan. 31, 2011

Dec. 31, 2021

Dec. 31, 2020

Jun. 16, 2020

Dec. 31, 2011

Proceeds from Issuance of Common Stock

$ 44,716,000

$ 21,337,000

Share Price (in dollars per share)

44,716,000

21,337,000

$ 0.7491

Common Stock, Value, Issued, Ending Balance

$ 137,000

$ 98,000

^[1]

Employee Stock Purchase Plan, Shares Issued, Weighted Average Fair Value (in dollars per share)

$ 1.01

$ 1.09

2011 Equity Incentive Plan [Member]

Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other Than Options, Outstanding (in shares)

1,900,000

Stock Option Plan Option Reserve Annual Increase as Percentage of Outstanding Shares Allowed

4.00%

Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)

5,500,000

The 2020 Equity Incentive Plan [Member]

Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)

5,500,000

Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized (in shares)

4,300,000

Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)

7,858,933

The 2020 Equity Incentive Plan [Member] | Maximum [Member]

Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)

4,300,000

Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares to be Added (in shares)

14,892,170

Employee Stock Purchase Plan (ESPP) [Member]

Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)

297,959

4,900,000

Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)

4,456,364

November 2021 Financing Warrants [Member]

Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)

17,500,000

Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)

$ 1.00

Warrants and Rights Outstanding

$ 5,600,000

$ 8,600,000

Private Placement [Member] | Armistice Capital and Rock Springs Capital [Member]

Stock Issued During Period, Shares, New Issues (in shares)

2,175,000

16,675,000

14,500,000

8,333,333

9,433,962

Shares Issued, Price Per Share (in dollars per share)

$ 1.7625

$ 1.20

$ 1.06

Proceeds from Issuance of Common Stock

$ 28,900,000

$ 9,900,000

$ 10,000,000.0

Estimated Offering Costs

$ 51,000

$ 49,000

2021 Registered Direct Offering [Member]

Stock Issued During Period, Shares, New Issues (in shares)

17,500,000

Shares Issued, Price Per Share (in dollars per share)

$ 0.80

Net Proceeds from Issuance of Common Stock and Exercise of Warrants

$ 13,900,000

Proceeds from Issuance or Sale of Equity, Total

13,100,000

14,000,000.0

Common Stock, Value, Issued, Ending Balance

$ 8,400,000

2021 Registered Direct Offering [Member] | November 2021 Financing Warrants [Member]

Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)

17,500,000

Stock Issued During Period, Shares, New Issues (in shares)

$ 17,500,000

ATM Agreement [Member]

3,000,000.0

876,800

Proceeds from Issuance of Common Stock

$ 7,500,000

$ 1,400,000

Aggregate Offering Price, Maximum

$ 80,000,000.0

$ 40,000,000.0

$ 36,100,000

Aggregate Offering Price, Increase During Period

$ 40,000,000.0

[1]	The condensed consolidated balance sheet as of December 31, 2020 has been derived from the audited financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020.

Note 14 - Stock Based Compensation (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Mar. 03, 2021	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)		$ 1.24	$ 0.92
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total		$ 3,800
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)		2 years 1 month 6 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value		$ 2,400	$ 3,600
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value		$ 5,700	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)		2,667,612
The 2020 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)		7,858,933
The 2020 Equity Incentive Plan [Member] \| Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)			0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares (in shares)		0
The 2020 Equity Incentive Plan [Member] \| Executive Officer [Member] \| Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)	$ 1.88
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)	1,270,000

Note 14 - Stock Based Compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Stock-based compensation expense	$ 4,609	$ 4,424
Cost of Sales [Member]
Stock-based compensation expense	92	123
Research and Development Expense [Member]
Stock-based compensation expense	813	764
Selling, General and Administrative Expenses [Member]
Stock-based compensation expense	$ 3,704	$ 3,537

Note 14 - Stock Based Compensation - Restricted Stock Activity (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Restricted stock units outstanding (in shares)	1,397,983	988,645
Restricted stock units weighted average outstanding (in dollars per share)	$ 1.79	$ 2.53
Granted (in shares)	1,149,632	908,300
Weighted average grant date fair value, granted (in dollars per share)	$ 1.68	$ 1.30
Vested (in shares)	(587,214)	(304,810)
Weighted average grant date fair value, vested (in dollars per share)	$ 1.89	$ 2.53
Forfeited (in shares)	(186,025)	(194,152)
Weighted average grant date fair value, forfeited (in dollars per share)	$ 1.58	$ 2.16
Restricted stock units outstanding (in shares)	1,774,376	1,397,983
Restricted stock units weighted average outstanding (in dollars per share)	$ 1.71	$ 1.79

Note 14 - Stock Based Compensation - Option Activity (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) $ / shares shares
Outstanding (in shares) \| shares	12,813,022
Outstanding (in dollars per share) \| $ / shares	$ 3.20
Granted (in shares) \| shares	2,667,612
Granted, weighted-average exercise price (in dollars per share) \| $ / shares	$ 1.82
Forfeited (in shares) \| shares	(375,432)
Forfeited, weighted-average exercise price (in dollars per share) \| $ / shares	$ 1.79
Expired (in shares) \| shares	(801,749)
Expired, weighted-average exercise price (in dollars per share) \| $ / shares	$ 3.03
Exercised (in shares) \| shares	(19,403)
Exercised, weighted-average exercise price (in dollars per share) \| $ / shares	$ 0.84
Outstanding (in shares) \| shares	14,284,050
Outstanding, weighted-average exercise price (in dollars per share) \| $ / shares	$ 2.99
Outstanding, weighted-average remaining contractual life (Year)	5 years 9 months 18 days
Outstanding, aggregate intrinsic value \| $	$ 0
Vested and exercisable options (in shares) \| shares	10,496,744
Vested and exercisable options, weighted-average exercise price (in dollars per share) \| $ / shares	$ 3.42
Vested and exercisable options, weighted-average remaining contractual life (Year)	4 years 9 months 18 days
Vested and exercisable options, aggregate intrinsic value \| $	$ 0
Vested and expected to vest (in shares) \| shares	14,284,050
Vested and expected to vest, weighted-average exercise price (in dollars per share) \| $ / shares	$ 2.99
Vested and expected to vest, weighted-average remaining contractual life (Year)	5 years 9 months 18 days
Vested and expected to vest, aggregate intrinsic value \| $	$ 0

Note 14 - Stock Based Compensation - Stock Options Outstanding, Vested and Exercisable (Details) - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Exercise Price Range, Upper Range Limit (in dollars per share)
Number of Stock Options Outstanding (in shares)	14,284,050	12,813,022
Weighted-average Remaining Contractual LIfe (Year)	5 years 9 months 18 days
Options Outstanding, Weighted-average Exercise Price Per Share (in dollars per share)	$ 2.99	$ 3.20
Shares Subject to Stock Options (in shares)	10,496,744
Options Vested and Exercisable, Weighted-average Exercise Price Per Share (in dollars per share)	$ 3.42
Exercise Price Range 1 [Member]
Exercise Price Range, Lower Range Limit (in dollars per share)	0.72
Exercise Price Range, Upper Range Limit (in dollars per share)	$ 1.12
Number of Stock Options Outstanding (in shares)	695,482
Weighted-average Remaining Contractual LIfe (Year)	8 years 1 month 6 days
Options Outstanding, Weighted-average Exercise Price Per Share (in dollars per share)	$ 0.85
Shares Subject to Stock Options (in shares)	280,047
Options Vested and Exercisable, Weighted-average Exercise Price Per Share (in dollars per share)	$ 0.84
Exercise Price Range 2 [Member]
Exercise Price Range, Lower Range Limit (in dollars per share)	1.26
Exercise Price Range, Upper Range Limit (in dollars per share)	$ 1.89
Number of Stock Options Outstanding (in shares)	3,402,418
Weighted-average Remaining Contractual LIfe (Year)	8 years 10 months 24 days
Options Outstanding, Weighted-average Exercise Price Per Share (in dollars per share)	$ 1.80
Shares Subject to Stock Options (in shares)	496,679
Options Vested and Exercisable, Weighted-average Exercise Price Per Share (in dollars per share)	$ 1.67
Exercise Price Range 3 [Member]
Exercise Price Range, Lower Range Limit (in dollars per share)	2.00
Exercise Price Range, Upper Range Limit (in dollars per share)	$ 3.00
Number of Stock Options Outstanding (in shares)	5,310,550
Weighted-average Remaining Contractual LIfe (Year)	6 years 1 month 6 days
Options Outstanding, Weighted-average Exercise Price Per Share (in dollars per share)	$ 2.44
Shares Subject to Stock Options (in shares)	4,856,618
Options Vested and Exercisable, Weighted-average Exercise Price Per Share (in dollars per share)	$ 2.43
Exercise Price Range 4 [Member]
Exercise Price Range, Lower Range Limit (in dollars per share)	3.10
Exercise Price Range, Upper Range Limit (in dollars per share)	$ 4.65
Number of Stock Options Outstanding (in shares)	3,066,819
Weighted-average Remaining Contractual LIfe (Year)	3 years 9 months 18 days
Options Outstanding, Weighted-average Exercise Price Per Share (in dollars per share)	$ 3.37
Shares Subject to Stock Options (in shares)	3,054,619
Options Vested and Exercisable, Weighted-average Exercise Price Per Share (in dollars per share)	$ 3.38
Exercise Price Range 5 [Member]
Exercise Price Range, Lower Range Limit (in dollars per share)	4.73
Exercise Price Range, Upper Range Limit (in dollars per share)	$ 7.10
Number of Stock Options Outstanding (in shares)	1,295,781
Weighted-average Remaining Contractual LIfe (Year)	1 year 9 months 18 days
Options Outstanding, Weighted-average Exercise Price Per Share (in dollars per share)	$ 5.71
Shares Subject to Stock Options (in shares)	1,295,781
Options Vested and Exercisable, Weighted-average Exercise Price Per Share (in dollars per share)	$ 5.71
Exercise Price Range 6 [Member]
Exercise Price Range, Lower Range Limit (in dollars per share)	8.18
Exercise Price Range, Upper Range Limit (in dollars per share)	$ 12.27
Number of Stock Options Outstanding (in shares)	513,000
Weighted-average Remaining Contractual LIfe (Year)	2 years 1 month 6 days
Options Outstanding, Weighted-average Exercise Price Per Share (in dollars per share)	$ 10.28
Shares Subject to Stock Options (in shares)	513,000
Options Vested and Exercisable, Weighted-average Exercise Price Per Share (in dollars per share)	$ 10.28

Note 14 - Stock Based Compensation - Assumptions to Calculate Fair Value of Each Performance-based Stock Option (Details) - Performance Shares [Member]	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Risk-free interest rate	1.50%	0.00%
Expected volatility	90.00%	0.00%
Expected dividend rate	0.00%	0.00%
Minimum [Member]
Derived service period (in years) (Year)	2 years 3 months 18 days
Maximum [Member]
Derived service period (in years) (Year)	2 years 7 months 6 days

Note 14 - Stock Based Compensation - Assumptions to Calculate Fair Value of Each Employee Stock Option (Details) - Time-based Stock Option [Member]	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Expected term (Year)	6 years 2 months 12 days	6 years 2 months 12 days
Risk-free interest rate, minimum	0.90%
Risk-free interest rate, maximum	1.30%
Expected volatility	90.00%	83.00%
Expected dividend rate	0.00%	0.00%
Minimum [Member]
Expected term (Year)	6 years
Risk-free interest rate, minimum		0.40%
Maximum [Member]
Risk-free interest rate, maximum		1.50%

Note 15 - Net Loss Per Share of Common Stock - Common Stock Excluded From Computation of Diluted Net Loss Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
RSU's, ESPP, and Employee Stock Options [Member]
Antidilutive securities (in shares)	16,328,426	14,541,005
Warrant [Member]
Antidilutive securities (in shares)	17,676,679	176,679

Note 16 - Accrued Liabilities - Accrued Liabilities (Details) - USD ($)
$ in Thousands

Dec. 31, 2021

Dec. 31, 2020

Accrued compensation and employee benefits

$ 2,974

$ 3,323

Accrued professional services

1,523

179

Accrued product returns and sales allowances

775

656

Deferred revenue

Other accrued liabilities

1,166

838

Total accrued liabilities

$ 6,524

$ 5,045

^[1]

[1]	The condensed consolidated balance sheet as of December 31, 2020 has been derived from the audited financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020.

Note 17 - 401(k) Plan (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Contribution Plan, Employer Discretionary Contribution Percentage			4.00%
Contributions by Employer to Postemployment Benefit Obligations	$ 0.4	$ 0.5

Note 18 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Expense (Benefit), Total	$ 5	$ 4
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	6,400	11,400
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Total	$ 0	$ 0
Open Tax Year	2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2016 2017 2018 2019 2020 2021
Increase (Decrease) in Employee Related Liabilities, Total	$ 1,400
Subject to Expiration [Member]
Operating Loss Carryforwards, Total	1,400
Research Tax Credit Carryforward [Member] \| Subject to Expiration [Member]
Tax Credit Carryforward, Amount	26
Domestic Tax Authority [Member]
Operating Loss Carryforwards, Total	308,500
Domestic Tax Authority [Member] \| Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	6,500
Domestic Tax Authority [Member] \| Before Tax Year 2018 [Member]
Operating Loss Carryforwards, Total	114,900
Domestic Tax Authority [Member] \| Tax Years 2018 to 2020 [Member]
Operating Loss Carryforwards, Total	193,600
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total	154,700
State and Local Jurisdiction [Member] \| Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	$ 4,000

Note 18 - Income Taxes - Net Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accruals and other	$ 3,989	$ 4,136
Research credits	7,275	7,275
Net operating loss carryforward	75,452	65,274
Section 59(e) R&D expenditures	5,070	7,473
Deferred revenue	19,666	20,848
Total deferred tax assets	111,452	105,006
Valuation allowance	(111,452)	(105,006)
Net deferred tax assets	$ 0	$ 0

Note 18 - Income Taxes - Reconciliation of Statutory Federal Income Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Tax at statutory federal rate	$ (7,370)	$ (8,486)
State tax—net of federal benefit	231	(3,587)
Stock options	718	636
Other	(20)	0
Change in valuation allowance	6,446	11,441
Provision for income taxes	$ 5	$ 4

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Note 18 - Income Taxes - Reconciliation of Beginning and Ending Balance of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Unrecognized benefit—beginning of period	$ 2,635	$ 2,635
Gross increases—prior period tax positions	0	0
Gross increases—current period tax positions	0	0
Unrecognized benefit—end of period	$ 2,635	$ 2,635

Note 19 - Subsequent Events (Details Textual) - Lowell Therapeutics [Member] - USD ($)	Jan. 07, 2022	Dec. 31, 2021
Other Assets [Member]
Acquisition Costs, Cumulative		$ 1,900,000
Subsequent Event [Member]
Business Combination, Consideration Transferred, Net of Cash Acquired	$ 32,500,000
Subsequent Event [Member] \| AcelRx Common Stock [Member]
Business Combination, Options To Purchase Capital Stock Issued and Outstanding Cancelled, Exchange for Common Stock, Number (in shares)	9,009,538
Business Combination, Options To Purchase Capital Stock Issued and Outstanding Cancelled, Exchange for Cash	$ 3,519,129
Business Combination, Acquiree Common Stock to Be Held Back to Satisfy Some Obligations (in shares)	1,396,526
Business Combination, Contingent Consideration, Liability, Total	$ 26,000,000.0
Business Combination, Acquiree Common Stock to Be Held Back to Satisfy Some Obligations, Fixed Value per Share (in dollars per share)	$ 0.57284

Schedule II - Valuation and Qualifying Accounts - Valuation and Qualifying Accounts (Details) - SEC Schedule, 12-09, Allowance, Sales and Returns, Discounts, Chargebacks and Rebates [Member] - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2021

Dec. 31, 2020

$ 668

$ 161

Additions

1,012

645

Deductions

^[1]

(900)

(138)