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1. Organization and Summary of Significant Accounting Policies The Company AcelRx Pharmaceuticals, Inc., or AcelRx or the Company, is a development stage company that was incorporated in Delaware on July 13, 2005 as SuRx, Inc. In January 2006, the Company changed its name to AcelRx Pharmaceuticals, Inc. The Company’s operations are based in Redwood City, California. The Company is a specialty pharmaceutical company focused on the development and commercialization of innovative therapies for the treatment of acute and breakthrough pain. Since incorporation, primary activities have consisted of establishing facilities, recruiting personnel, conducting research and development of its product candidates, developing intellectual property and raising capital. To date, the Company has not yet commenced primary operations or generated any significant revenues and, accordingly, the Company is considered to be in the development stage. The Company has one business activity, which is the development and commercialization of product candidates for the treatment of pain, and a single reporting and operating unit structure. The Company has incurred recurring operating losses and negative cash flows from operating activities since inception through June 30, 2012. In addition, the Company had an accumulated deficit of $102.9 million and $88.7 million as of June 30, 2012 and December 31, 2011. Through June 30, 2012, the Company has relied primarily on the proceeds from equity offerings and loan proceeds to finance its operations. Management believes that the Company’s current cash, cash equivalents and investments will be sufficient to fund the Company’s current operations into the second quarter of 2013. The Company will need to raise additional funding or otherwise enter into collaborations to fund future operations. However, there is no assurance that additional funding will be available to the Company on acceptable terms on a timely basis, if at all, or that the Company will achieve profitable operations. If the Company is unable to raise additional capital to fund its operations, it will need to curtail planned activities to reduce costs. Doing so may affect the Company’s ability to operate effectively. The accompanying financial statements do not include any adjustments that might result from the outcome of these uncertainties. Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and the rules and regulations of the U.S. Securities and Exchange Commission, or SEC. Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation have been included. Operating results for the three and six months ended June 30, 2012 are not necessarily indicative of the results that may be expected for the year ending December 31, 2012. The condensed balance sheet as of December 31, 2011 was derived from the Company’s audited financial statements as of December 31, 2011, included in the Company’s Annual Report on Form 10-K filed with the SEC. These financial statements should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2011, which include a broader discussion of the Company’s business and the risks inherent therein. Initial Public Offering On February 10, 2011, the Company sold 8,000,000 shares of common stock at a price of $5.00 per share in its initial public offering, or the IPO. The shares began trading on the NASDAQ Global Market on February 11, 2011. The Company received $34.9 million in net proceeds from the IPO, after deducting an estimated $5.1 million in underwriting discounts and commissions and other offering-related expenses payable by the Company. Upon the closing of the offering, all outstanding shares of convertible preferred stock converted into common stock. The convertible preferred stock converted into 8,555,713 shares of common stock. In addition, the principal and accrued interest under the 2010 Convertible Notes, as defined in Note 5 “Convertible Notes,” converted into 2,034,438 shares of common stock immediately prior to the closing of the Company’s IPO and the 2010 Warrants, as defined in Note 6 “Warrants,” were net exercised for 107,246 shares of Series C convertible preferred stock, which shares were converted to common stock immediately prior to the closing of the Company’s IPO. All other outstanding warrants to purchase convertible preferred stock became exercisable for shares of common stock. 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 condensed financial statements and accompanying notes. On an ongoing basis, management evaluates its estimates, 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. Newly Adopted Accounting Pronouncements In June of 2011, Accounting Standards Codification Topic 220, Comprehensive Income was amended to increase the prominence of items reported in other comprehensive income. Accordingly, a company can present all non-owner changes in stockholders’ equity either in a single continuous statement of comprehensive income or in two separate but consecutive statements. The Company adopted this guidance as of January 1, 2012 on a retrospective basis and this adoption did not have a material effect on the Company’s financial statements. In May of 2011, Accounting Standards Codification Topic 820, Fair Value Measurement was amended to develop common requirements for measuring fair value and for disclosing information about fair value measurements in accordance with U.S. generally accepted accounting principles and International Financial Reporting Standards. The Company adopted this guidance as of January 1, 2012 on a retrospective basis and this adoption did not have a material effect on the Company’s financial statements.

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, with the unrealized holding gains and losses included in accumulated other comprehensive income. 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):   <table cellspacing="0" cellpadding="0" width="92%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="55%"> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="14" align="center" style="border-bottom:1px solid #000000">As of June 30, 2012</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Amortized Cost</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Gross  Unrealized Gains</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Gross  Unrealized Losses</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Fair Value</td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Cash and cash equivalents: </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr> <td valign="top"> Cash </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">1,236</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">1,236</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Money market funds </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">2,716</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">2,716</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr> <td valign="top"> U.S. government agency securities </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">3,591</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(1</td> <td nowrap="nowrap" valign="bottom">)</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">3,590</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Total cash and cash equivalents </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">7,543</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">7,542</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr> <td valign="top"> Marketable securities: </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> U.S. government agency securities </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">24,393</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(2</td> <td nowrap="nowrap" valign="bottom">) </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">24,391</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr> <td valign="top"> Total marketable securities </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">24,393</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(2</td> <td nowrap="nowrap" valign="bottom">)</td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">24,391</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Total cash, cash equivalents and investments </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">31,936</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">(3</td> <td nowrap="nowrap" valign="bottom">)</td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">31,933</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr>  </table>   <table cellspacing="0" cellpadding="0" width="92%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="55%"> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="14" align="center" style="border-bottom:1px solid #000000">As of December 31, 2011</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Amortized Cost</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Gross  Unrealized Gains</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Gross  Unrealized Losses</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Fair Value</td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Cash and cash equivalents: </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr> <td valign="top"> Cash </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">641</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">641</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Money market funds </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">6,883</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">6,883</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr> <td valign="top"> U.S. government agency securities </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">270</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">270</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Total cash and cash equivalents </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">7,794</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">7,794</td> <td nowrap="nowrap" valign="bottom"> </td> </tr>  </table>   <table cellspacing="0" cellpadding="0" width="92%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="56%"> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="14" align="center" style="border-bottom:1px solid #000000">As of June 30, 2012</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Amortized Cost</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Gross  Unrealized Gains</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Gross  Unrealized Losses</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Fair Value</td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Marketable securities: </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr> <td valign="top"> U.S. government agency securities </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">27,991</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">27,991</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Total marketable securities </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">27,991</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">27,991</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr> <td valign="top"> Total cash, cash equivalents and investments </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">35,785</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">35,785</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr>  </table> As of June 30, 2012 and December 31, 2011 none of the available-for-sale securities held by the Company had material unrealized losses and there were no realized losses for the six months ended June 30, 2012. There were no other-than-temporary impairments for these securities at June 30, 2012 or December 31, 2011. As of June 30, 2012, 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 Level II assets and Level III liabilities. Level I securities include highly liquid money market funds and are valued based on quoted market prices. 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 and U.S. government agency obligations. As of June 30, 2012 and December 31, 2011, the Company held, in addition to Level I and Level II assets, a contingent put option liability associated with the Company’s loan and security agreement with Hercules Technology II, L.P. and Hercules Technology Growth Capital, Inc., collectively referred to as Hercules, which was classified as a Level III liability. As of June 30, 2012 and December 31, 2011, the estimated fair value of the contingent put option liability was $145,000 and $232,000, respectively, 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. The resulting difference between the two estimated fair values is the estimated fair value of the default provisions, or the contingent put option. 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. As of June 30, 2012, the Company also held a Level III liability associated with warrants issued in connection with the Company’s private placement equity offering, or PIPE warrants, completed in June 2012. The warrants are considered a liability and are valued using the Black-Scholes option-pricing model, the inputs for which include exercise price of the warrants, market price of the underlying common shares, expected term, volatility based on a group of the Company’s peers and the risk-free rate corresponding to the expected term of the warrants. Changes to one, or any, of the inputs impact the estimated fair value of the warrants. 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):   <table cellspacing="0" cellpadding="0" width="92%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="66%"> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="14" align="center" style="border-bottom:1px solid #000000">As of June 30, 2012</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Fair Value</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level I</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level II</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level III</td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Assets </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr> <td valign="top"> Money market funds </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">2,716</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">2,716</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> U.S. government agency obligations </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">27,981</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">27,981</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr> <td valign="top"> Total assets measured at fair value </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">30,697</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">2,716</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">27,981</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr> <td height="8"> </td> <td height="8" colspan="4"> </td> <td height="8" colspan="4"> </td> <td height="8" colspan="4"> </td> <td height="8" colspan="4"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Liabilities </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr> <td valign="top"> PIPE warrants </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">5,478</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">5,478</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Contingent put option liability </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">145</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">145</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr> <td valign="top"> Total liabilities measured at fair value </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">5,623</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">5,623</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr>  </table>   <table cellspacing="0" cellpadding="0" width="92%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="67%"> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="14" align="center" style="border-bottom:1px solid #000000">As of December 31, 2011</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Fair Value</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level I</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level II</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level III</td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Assets </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr> <td valign="top"> Money market funds </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">6,883</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">6,883</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> U.S. government agency obligations </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">28,261</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">28,261</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr> <td valign="top"> Total assets measured at fair value </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">35,144</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">6,883</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">28,261</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr>  </table>   <table cellspacing="0" cellpadding="0" width="92%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="76%"> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="14" align="center" style="border-bottom:1px solid #000000">As of June 30, 2012</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Fair Value</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level I</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level II</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level III</td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Liabilities </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr> <td valign="top"> Contingent put option liability </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">232</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">232</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Total liabilities measured at fair value </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">232</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">232</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr>  </table>   The following table sets forth the assumptions used in the Black-Scholes option-pricing model to estimate the fair value of the PIPE warrants as of June 30, 2012:   <table cellspacing="0" cellpadding="0" width="68%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="92%"> </td> <td valign="bottom" width="6%"> </td> <td> </td> <td> </td> <td> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Risk-free interest rate </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">0.72</td> <td nowrap="nowrap" valign="bottom">% </td> </tr> <tr> <td valign="top"> Expected volatility </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">79.0</td> <td nowrap="nowrap" valign="bottom">% </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Expected life (in years) </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">5.4</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr> <td valign="top"> Expected dividend yield </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">0.0</td> <td nowrap="nowrap" valign="bottom">% </td> </tr>  </table>   The following table sets forth a summary of the changes in the fair value of the Company’s Level III financial liabilities (in thousands):   <table cellspacing="0" cellpadding="0" width="68%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="80%"> </td> <td valign="bottom" width="15%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Six Months Ended June 30, 2012</td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Fair value—beginning of period </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">232</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr> <td valign="top"> Addition of private placement warrants on June 1, 2012 </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">5,828</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Change in fair value of private placement warrants </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(350</td> <td nowrap="nowrap" valign="bottom">) </td> </tr> <tr> <td valign="top"> Change in fair value of contingent put option </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(87</td> <td nowrap="nowrap" valign="bottom">) </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Fair value—end of period </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">5,623</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr>  </table>

3. Research Grant Agreement In May 2011, AcelRx entered into an award contract with the US Army Medical Research and Material Command, or USAMRMC, in which the USAMRMC granted $5.6 million to the Company in order to support the development of a new product candidate, ARX-04, a Sufentanil NanoTab for the treatment of moderate-to-severe acute pain. Under the terms of the grant, the USAMRMC will reimburse the Company for development, manufacturing and clinical costs necessary to prepare for and complete the planned Phase 2 dose-finding trial in a study of acute moderate-to-severe pain, and to prepare to enter Phase 3 development. The period of research under the grant was originally scheduled to end on August 31, 2012, with a final report due on September 30, 2012. In June 2012, due to a longer than expected administrative review process by the USAMRMC, the Company was awarded a no-cost extension of the grant whereby the period of research was extended through May 31, 2013, with a final report due on June 30, 2013. The grant gives the USAMRMC the option to extend the term of the grant and provide additional funding for the research. Revenue is recognized based on expenses incurred by AcelRx in conducting research and development activities set forth in the agreement. Revenue attributable to the research and development performed under the USAMRMC grant was $224,000 and $553,000 for the three and six months ended June 30, 2012, respectively, and $40,000 for each of the three and six month periods ended June 30, 2011. Revenue attributable to the research and development performed under the USAMRMC since inception was $1.6 million.

4. Long-Term Debt Hercules Loan and Security Agreement On June 29, 2011, AcelRx entered into a loan and security agreement with Hercules, under which AcelRx borrowed $20.0 million in two tranches of $10.0 million each, represented by secured convertible term promissory notes. The Company’s obligations associated with the agreement are secured by a security interest in substantially all of its assets, other than its intellectual property. The interest rate for each tranche is 8.50% and the Company will make interest only payments until June 30, 2012 followed by equal monthly payments of principal and interest through the scheduled maturity date on December 1, 2014. Upon an event of default, including a change of control, Hercules has the option to accelerate repayment of the loan, including payment of any applicable prepayment charges, which range from 1%-3% of the outstanding loan balance and accrued interest, as well as a final payment fee of $0.2 million. This option is considered a contingent put option liability as the holder of the loan may exercise the option in the event of default and, is considered an embedded derivative which must be valued and separately accounted for in the Company’s financial statements. The contingent put option liability was recorded as a debt discount to the loan and consequently a reduction to the carrying value of the loan. The contingent put option liability will be revalued at the end of each reporting period and any change in the fair value will be recognized in the statement of comprehensive loss. As of June 30, 2012, the estimated fair value of the contingent put option liability was $145,000. See Note 2 “Investments and Fair Value Measurement” for further description of the contingent put option liability. In connection with the loan, the Company issued Hercules seven-year warrants to purchase an aggregate of 274,508 shares of common stock at a price of $3.06 per share. See Note 7 “Warrants” for further description.   As of June 30, 2012, the Company had outstanding borrowings under the Hercules loan and security agreement of $19.3 million, net of debt discounts of $0.7 million. Amortization of the debt discounts, which was recorded as Interest Expense, was $138,000 and $272,000 for the three and six months ended June 30, 2012, respectively. Pinnacle Loan and Security Agreement In September 2008, the Company entered into a $12.0 million loan and security agreement with Pinnacle. In November 2008, the Company drew down all $12.0 million of the loan facility. On June 29, 2011, upon execution of the Hercules loan and security agreement, the Pinnacle agreement was terminated and the outstanding balance of $2.8 million was repaid. The unamortized portions of the final payment and deferred financing costs were recorded to interest expense upon termination of the agreement.

5. 2012 Private Placement Offering On June 1, 2012, or the Issuance Date, the Company issued an aggregate of 2,922,337 shares of common stock and warrants to purchase up to 2,630,103 shares of common stock, or the Warrants, for aggregate gross proceeds of $10.0 million, or the Private Placement. Costs related to the offering were $0.9 million. The shares of common stock and Warrants issued in the Private Placement were sold pursuant to a Securities Purchase Agreement, or Purchase Agreement, dated May 29, 2012, between the Company and certain purchasers, including certain entities affiliated with Mark Wan and Stephen J. Hoffman, members of the Company’s board of directors. Pursuant to the Purchase Agreement, AcelRx sold shares of common stock and Warrants to purchase common stock in immediately separable “Units,” with each Unit consisting of (i) one share of common stock and (ii) a Warrant to purchase 0.9 of a share of common stock. The per share exercise price of the Warrants was $3.40. The offering price per Unit was $3.40 for non-affiliated investors, and $3.5125 for affiliated investors, which equals the sum of (i) $3.40, the closing consolidated bid price of our common stock on May 29, 2012, plus (ii) $0.1125 (which is equal to $0.125 per warrant share, multiplied by 0.9), for an aggregate amount of $10.0 million. The Warrants issued in the Private Placement become exercisable six months after the Issuance Date, and expire on the five year anniversary of the initial exercisability date. In connection with the Private Placement, the Company agreed to file a registration statement with the U.S. Securities and Exchange Commission, or SEC, registering for resale the shares of common stock and shares of common stock issuable upon exercise of the warrants sold in the Private Placement. The Company filed such registration statement with the SEC on June 21, 2012 and it was declared effective by the SEC on July 2, 2012.   6. Convertible Notes 2010 Convertible Notes On September 14, 2010, the Company sold convertible promissory notes, or the 2010 Convertible Notes, to certain existing investors for an aggregate purchase price of $8.0 million, with an option for the holders of the 2010 Convertible Notes to purchase an additional $4.0 million of the 2010 Convertible Notes. This option was determined to be a call option that was recorded at its fair value of $476,000 as a debt discount that would have been amortized to interest expense over the one-year term of the 2010 Convertible Notes. The fair value of the call option was determined by evaluating multiple potential outcomes using a market approach and an income approach depending on the scenario and discounting these values back to the appropriate date while applying estimated probabilities to each scenario value. The call option was revalued to its fair value as of the IPO date and was written off upon its expiration with a benefit of $596,000 being recognized through other income (expense) during the six months ended June 30, 2011. In addition, the unamortized debt discount in the amount of $1.1 million at the time of the IPO was recognized as interest expense in connection with the conversion of the notes. In connection with the IPO, the outstanding principal and accrued interest under the 2010 Convertible Notes automatically converted into 2,034,438 shares of common stock immediately prior to the closing of the IPO.     7. Warrants Series A Warrants In March 2007, the Company entered into an equipment financing agreement in which the Company issued immediately exercisable and fully vested warrants to purchase 2,500 shares of its Series A convertible preferred stock, or the Series A warrants, with an exercise price of $10.00 per share. The fair value of the Series A warrants on the date of issuance was $1,000, as determined using the Black-Scholes option-pricing model. This fair value was recorded as a convertible preferred stock warrant liability and as a deferred financing cost in other assets. The fair value was remeasured at the end of each reporting period. In connection with the IPO, the Series A warrants were automatically converted into warrants to purchase 3,425 shares of common stock. As a result of the conversion, these common stock warrants were no longer recorded as liabilities and were, therefore, no longer remeasured as of the end of each reporting period. As of June 30, 2012, warrants to purchase 3,425 shares of common stock had not been exercised and were outstanding. These warrants expire in March 2017. Series B and Series C Warrants Upon the closing of the Series C convertible preferred stock financing during the year ended December 31, 2009, the Series B warrants underlying the loan and security agreement with Pinnacle Ventures became exercisable for 228,264 shares of Series C convertible preferred stock with an exercise price of $3.94 per share, or the Series C warrants. The Company revalued the convertible preferred stock warrant liability related to the Series B warrants and Series C warrants during each reporting period using the Black-Scholes option-pricing model and the fair value was estimated to be $894,000 as of the IPO date in February 2011. In connection with the Company’s IPO in February 2011, the Series C warrants were automatically converted into warrants to purchase 228,264 shares of common stock. Immediately before the conversion to common stock warrants, the Series C warrants were remeasured to fair value with the change in the fair value of these warrants of $323,000 being recorded as a benefit through other income (expense), net during the six months ended June 30, 2011. Immediately after the conversion to common stock warrants, the remaining liability of $894,000 was reclassified to additional paid-in capital. As a result of the conversion, these common stock warrants were no longer recorded as liabilities and were therefore no longer remeasured as of the end of each reporting period. As of June 30, 2012, warrants to purchase 228,264 shares of common stock had not been exercised and were outstanding. These warrants expire in September 2018. 2010 Warrants The Company issued warrants in connection with the 2010 Convertible Notes in September 2010, or the 2010 Warrants. The 2010 Warrants were exercisable into shares of convertible preferred stock. The 2010 Warrants would have terminated if not exercised immediately prior to the IPO. The 2010 Warrants allowed for cashless exercises. The Company determined the fair value of the 2010 Warrants to be $1.2 million upon issuance, as determined using the Black-Scholes option-pricing model which was recorded as a convertible preferred stock warrant liability and a debt discount. As of December 31, 2010, the related warrant liability was $1.3 million. In connection with the IPO, the 2010 Warrants were net exercised into shares of Series C convertible preferred stock, which shares were automatically converted to 107,246 shares of common stock immediately prior to the IPO. Immediately before the exercise into Series C convertible preferred stock, the 2010 Warrants were remeasured to fair value with the change in the fair value of these warrants of $796,000 being recorded as a benefit through other income (expense), net during the six months ended June 30, 2011. Immediately after the exercise into Series C convertible preferred stock, the remaining liability of $536,000 was reclassified to additional paid-in capital. Hercules Warrants In connection with the loan and security agreement with Hercules, the Company issued to Hercules warrants to purchase an aggregate of 274,508 shares of common stock at a price of $3.06 per share. The warrants may be exercised on a cashless basis. The warrants are exercisable for a term beginning on the date of issuance and ending on the earlier to occur of seven years from the date of issuance or the consummation of certain acquisitions of the Company as set forth in the warrants. The Company estimated the fair value of these warrants as of the issuance date to be $967,000, which was recorded as a debt discount to the loan and consequently a reduction to the carrying value of the loan. The fair value of the warrants was calculated using the Black-Scholes option-pricing model. The Company also recorded fees paid to Hercules as a debt discount, which further reduced the carrying value of the loan. The debt discount is being amortized to interest expense. As of June 30, 2012, warrants to purchase 274,508 shares of common stock issued to Hercules had not been exercised and were outstanding.   2012 Private Placement Warrants In connection with the Private Placement, the Company issued Warrants to purchase up to 2,630,103 shares of common stock. The per share exercise price of the Warrants was $3.40 which equals the closing consolidated bid price of the Company’s common stock on May 29, 2012, the effective date of the Purchase Agreement. The Warrants issued in the Private Placement become exercisable six months after the issuance date, and expire on the five year anniversary of the initial exercisability date. Under the terms of the Warrants, upon certain transactions, including a merger, tender offer, sale of all or substantially all of the assets of the Company or if a person or group shall become the owner of 50% of the Company’s issued and outstanding common stock, which is outside of the Company’s control, each Warrant holder may elect to receive a cash payment in exchange for the warrant, in an amount determined by application of the Black-Scholes option-pricing model. Accordingly, the Warrants were recorded as a liability at fair value, as determined by the Black-Scholes option-pricing model, and then marked to fair value each reporting period, with changes in estimated fair value recorded through the Statement of Comprehensive Loss in other income or expense. Upon execution of the Purchase Agreement, the fair value of the warrants was estimated to be $5.8 million, which was recorded as a liability. As of June 30, 2012, the fair value of the Warrants was estimated to be $5.5 million, with the change in fair value from the initial measurement date, recorded in other income for the three and six months ended June 30, 2012. As of June 30, 2012, Warrants to purchase 2,630,103 shares of common stock issued in connection with the Private Placement had not been exercised and were outstanding.

8. Stock-Based Compensation The Company recorded total stock-based compensation expense for stock options, stock awards and the 2011 Employee Stock Purchase Plan as follows (in thousands):   <table cellspacing="0" cellpadding="0" width="100%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="66%"> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="6" align="center"> Three Months Ended June 30, </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="6" align="center" style="border-bottom:1px solid #000000">Six Months Ended June 30,</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" rowspan="2" align="center" style="border-bottom:1px solid #000000">Period from July 13, 2005 (Inception) Through June 30, 2012</td> <td valign="bottom" rowspan="2"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center">2012</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center">2011</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">2012</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">2011</td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Expenses: </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr> <td valign="top"> Research and development </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">254</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">204</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">505</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">325</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">2,884</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> General and administrative </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">276</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">262</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">566</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">464</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">2,533</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr> <td valign="top"> Total stock-based compensation expense </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">530</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">466</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">1,071</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">789</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">5,417</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr>  </table> As of June 30, 2012 there were 883,904 shares available for future grant, 3,308,135 options outstanding and 165,659 restricted stock units outstanding under the Company’s 2011 Equity Incentive Plan.

9. Net Loss per Share of Common Stock The following table sets forth the computation of the Company’s basic and diluted net loss per share of common stock during the three and six months ended June 30, 2012 and 2011 (in thousands, except for share and per share amounts):   <table cellspacing="0" cellpadding="0" width="92%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="55%"> </td> <td valign="bottom" width="6%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="6%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="6%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="3%"> </td> <td> </td> <td> </td> <td valign="bottom" width="3%"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="6" align="center" style="border-bottom:1px solid #000000">Three Months Ended June  30,</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="6" align="center" style="border-bottom:1px solid #000000">Six Months Ended June 30,</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">2012</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">2011</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">2012</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">2011</td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Net loss </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">(7,194</td> <td nowrap="nowrap" valign="bottom">) </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">(4,763</td> <td nowrap="nowrap" valign="bottom">) </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">(14,259</td> <td nowrap="nowrap" valign="bottom">) </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">(7,967</td> <td nowrap="nowrap" valign="bottom">) </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr> <td valign="top"> Shares used in computing net loss per share of common stock, basic and diluted </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">20,627,244</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">19,374,909</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">20,114,608</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">15,058,546</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Net loss per share of common stock, basic and diluted </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">(0.35</td> <td nowrap="nowrap" valign="bottom">) </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">(0.25</td> <td nowrap="nowrap" valign="bottom">) </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">(0.71</td> <td nowrap="nowrap" valign="bottom">) </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">(0.53</td> <td nowrap="nowrap" valign="bottom">) </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr>  </table>   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:   <table cellspacing="0" cellpadding="0" width="76%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="76%"> </td> <td valign="bottom" width="3%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="3%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="6" align="center" style="border-bottom:1px solid #000000">June 30,</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">2012</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">2011</td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Stock options to purchase common stock </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">3,307,457</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">2,416,877</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr> <td valign="top"> Restricted stock units </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">166,335</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">343,815</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Common stock warrants </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">3,136,300</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">506,197</td> <td nowrap="nowrap" valign="bottom"> </td> </tr>  </table>

The Company AcelRx Pharmaceuticals, Inc., or AcelRx or the Company, is a development stage company that was incorporated in Delaware on July 13, 2005 as SuRx, Inc. In January 2006, the Company changed its name to AcelRx Pharmaceuticals, Inc. The Company’s operations are based in Redwood City, California. The Company is a specialty pharmaceutical company focused on the development and commercialization of innovative therapies for the treatment of acute and breakthrough pain. Since incorporation, primary activities have consisted of establishing facilities, recruiting personnel, conducting research and development of its product candidates, developing intellectual property and raising capital. To date, the Company has not yet commenced primary operations or generated any significant revenues and, accordingly, the Company is considered to be in the development stage. The Company has one business activity, which is the development and commercialization of product candidates for the treatment of pain, and a single reporting and operating unit structure. The Company has incurred recurring operating losses and negative cash flows from operating activities since inception through June 30, 2012. In addition, the Company had an accumulated deficit of $102.9 million and $88.7 million as of June 30, 2012 and December 31, 2011. Through June 30, 2012, the Company has relied primarily on the proceeds from equity offerings and loan proceeds to finance its operations. Management believes that the Company’s current cash, cash equivalents and investments will be sufficient to fund the Company’s current operations into the second quarter of 2013. The Company will need to raise additional funding or otherwise enter into collaborations to fund future operations. However, there is no assurance that additional funding will be available to the Company on acceptable terms on a timely basis, if at all, or that the Company will achieve profitable operations. If the Company is unable to raise additional capital to fund its operations, it will need to curtail planned activities to reduce costs. Doing so may affect the Company’s ability to operate effectively. The accompanying financial statements do not include any adjustments that might result from the outcome of these uncertainties.

The table below summarizes the Company’s cash, cash equivalents and investments (in thousands):   <table cellspacing="0" cellpadding="0" width="92%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="55%"> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="14" align="center" style="border-bottom:1px solid #000000">As of June 30, 2012</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Amortized Cost</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Gross  Unrealized Gains</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Gross  Unrealized Losses</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Fair Value</td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Cash and cash equivalents: </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr> <td valign="top"> Cash </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">1,236</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">1,236</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Money market funds </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">2,716</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">2,716</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr> <td valign="top"> U.S. government agency securities </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">3,591</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(1</td> <td nowrap="nowrap" valign="bottom">)</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">3,590</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Total cash and cash equivalents </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">7,543</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">7,542</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr> <td valign="top"> Marketable securities: </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> U.S. government agency securities </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">24,393</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(2</td> <td nowrap="nowrap" valign="bottom">) </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">24,391</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr> <td valign="top"> Total marketable securities </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">24,393</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(2</td> <td nowrap="nowrap" valign="bottom">)</td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">24,391</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Total cash, cash equivalents and investments </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">31,936</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">(3</td> <td nowrap="nowrap" valign="bottom">)</td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">31,933</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr>  </table>   <table cellspacing="0" cellpadding="0" width="92%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="55%"> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="14" align="center" style="border-bottom:1px solid #000000">As of December 31, 2011</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Amortized Cost</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Gross  Unrealized Gains</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Gross  Unrealized Losses</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Fair Value</td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Cash and cash equivalents: </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr> <td valign="top"> Cash </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">641</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">641</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Money market funds </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">6,883</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">6,883</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr> <td valign="top"> U.S. government agency securities </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">270</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">270</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Total cash and cash equivalents </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">7,794</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">7,794</td> <td nowrap="nowrap" valign="bottom"> </td> </tr>  </table>   <table cellspacing="0" cellpadding="0" width="92%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="56%"> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="8%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="14" align="center" style="border-bottom:1px solid #000000">As of June 30, 2012</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Amortized Cost</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Gross  Unrealized Gains</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Gross  Unrealized Losses</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Fair Value</td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Marketable securities: </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr> <td valign="top"> U.S. government agency securities </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">27,991</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">27,991</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Total marketable securities </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">27,991</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">27,991</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr> <td valign="top"> Total cash, cash equivalents and investments </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">35,785</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">35,785</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr>  </table>

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):   <table cellspacing="0" cellpadding="0" width="92%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="66%"> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="14" align="center" style="border-bottom:1px solid #000000">As of June 30, 2012</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Fair Value</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level I</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level II</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level III</td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Assets </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr> <td valign="top"> Money market funds </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">2,716</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">2,716</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> U.S. government agency obligations </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">27,981</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">27,981</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr> <td valign="top"> Total assets measured at fair value </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">30,697</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">2,716</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">27,981</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr> <td height="8"> </td> <td height="8" colspan="4"> </td> <td height="8" colspan="4"> </td> <td height="8" colspan="4"> </td> <td height="8" colspan="4"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Liabilities </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr> <td valign="top"> PIPE warrants </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">5,478</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">5,478</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Contingent put option liability </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">145</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">145</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr> <td valign="top"> Total liabilities measured at fair value </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">5,623</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">5,623</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr>  </table>   <table cellspacing="0" cellpadding="0" width="92%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="67%"> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="14" align="center" style="border-bottom:1px solid #000000">As of December 31, 2011</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Fair Value</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level I</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level II</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level III</td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Assets </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr> <td valign="top"> Money market funds </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">6,883</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">6,883</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> U.S. government agency obligations </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">28,261</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">28,261</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr> <td valign="top"> Total assets measured at fair value </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">35,144</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">6,883</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">28,261</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr>  </table>   <table cellspacing="0" cellpadding="0" width="92%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="76%"> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="14" align="center" style="border-bottom:1px solid #000000">As of June 30, 2012</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Fair Value</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level I</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level II</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Level III</td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Liabilities </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr> <td valign="top"> Contingent put option liability </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">232</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom"> </td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">232</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Total liabilities measured at fair value </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">232</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td nowrap="nowrap" valign="bottom">$</td> <td nowrap="nowrap" valign="bottom" align="right">—  </td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">232</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr>  </table>

The following table sets forth a summary of the changes in the fair value of the Company’s Level III financial liabilities (in thousands):   <table cellspacing="0" cellpadding="0" width="68%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="80%"> </td> <td valign="bottom" width="15%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">Six Months Ended June 30, 2012</td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Fair value—beginning of period </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">232</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr> <td valign="top"> Addition of private placement warrants on June 1, 2012 </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">5,828</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Change in fair value of private placement warrants </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(350</td> <td nowrap="nowrap" valign="bottom">) </td> </tr> <tr> <td valign="top"> Change in fair value of contingent put option </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(87</td> <td nowrap="nowrap" valign="bottom">) </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> Fair value—end of period </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">5,623</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr>  </table>

The Company recorded total stock-based compensation expense for stock options, stock awards and the 2011 Employee Stock Purchase Plan as follows (in thousands):   <table cellspacing="0" cellpadding="0" width="100%" border="0" style="border-collapse:collapse; text-align: left" align="center">  <tr> <td width="66%"> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> <td valign="bottom" width="4%"> </td> <td> </td> <td> </td> <td> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="6" align="center"> Three Months Ended June 30, </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="6" align="center" style="border-bottom:1px solid #000000">Six Months Ended June 30,</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" rowspan="2" align="center" style="border-bottom:1px solid #000000">Period from July 13, 2005 (Inception) Through June 30, 2012</td> <td valign="bottom" rowspan="2"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center">2012</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center">2011</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">2012</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" colspan="2" align="center" style="border-bottom:1px solid #000000">2011</td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr>   <tr bgcolor="#cceeff"> <td valign="top"> Expenses: </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> </tr> <tr> <td valign="top"> Research and development </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">254</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">204</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">505</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">325</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">2,884</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr bgcolor="#cceeff"> <td valign="top"> General and administrative </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">276</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">262</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">566</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">464</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">2,533</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr> <tr> <td valign="top"> Total stock-based compensation expense </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">530</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">466</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">1,071</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">789</td> <td nowrap="nowrap" valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">5,417</td> <td nowrap="nowrap" valign="bottom"> </td> </tr> <tr style="font-size:1px"> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> <td valign="bottom"> </td> <td valign="bottom">   </td> <td valign="bottom">   </td> <td> </td> </tr>  </table>

5828000 P1Y 0.125 -350000 3.40 0.5 232000 145000 P1Y 476000 145000 1200000 894000 323000 967000 1000 5800000 200000 5500000 5500000 476000 1223000 6795000 967000 5828000 2012-06-30 beyond one year 62000 62000 0.9 1 2 900000 3.5125 3.40 596000 0.03 0.01 865000 906000 906000 -521000 -1682000 -437000 1600000 0.1125 P7Y P6M P5Y 1300000 894000 September 2018 March 2017 false --12-31 Q2 2012 2012-06-30 10-Q 0001427925 22625000 Smaller Reporting Company ACELRX PHARMACEUTICALS INC 10.00 3.94 3.06 3.06 3.40

1530000

1197000

-439000

-78000

-244000

2565000

2483000

-3000

106110000

110531000

536000

272000

138000

506197

343815

2416877

3136300

166335

3307457

40835000

36644000

38146000

33690000

35144000

28261000

6883000

28261000

6883000

28261000

6883000

30697000

27981000

2716000

27981000

2716000

27981000

2716000

35785000

27991000

7794000

27991000

641000

6883000

270000

31936000

24393000

7543000

24393000

1236000

2716000

3591000

35785000

27991000

7794000

27991000

641000

6883000

270000

31933000

24391000

7542000

24391000

1236000

2716000

3590000

3000

2000

1000

3055000

18760000

7794000

7542000

15705000

-252000

3.40

2630103

0.001

100000000

8000000

19567778

22625000

19567778

22625000

165659

22000

23000

-102926000

-7969000

-4763000

-14262000

-7195000

40000

553000

224000

8137000

2034438

107246

8000000

4000000

8555713

107246

2500

228264

107246

228264

274508

228264

3425

2630103

1699000

2034438

20000000

10000000

0.0850

2010-09-14

2014-12-01

1100000

700000

15000

378000

2414000

232000

336000

-0.53

-0.25

-0.71

-0.35

0.00

P5Y4M24D

0.7900

0.0072

-87000

232000

5623000

23174000

3220000

1630000

3880000

1776000

-99135000

-8155000

-4619000

-13492000

-6946000

1196000

863000

-334000

747000

557000

-131000

480000

-94000

411000

355000

-892000

-628000

205000

6631000

1514000

156000

1192000

598000

3160000

1306000

333000

3735000

196000

833000

23367000

29016000

40835000

36644000

7845000

10693000

232000

5623000

145000

5478000

5623000

145000

5478000

12000000

19300000

12000000

3750000

7013000

15275000

12322000

127521000

39461000

9180000

-29856000

-18730000

2668000

-90123000

-5026000

-12100000

-102923000

-7967000

-4763000

-14259000

-7194000

536000

2843000

1702000

12000

425000

350000

100760000

8195000

4659000

14045000

7170000

178000

132000

-3000

-2000

-3000

-1000

-28000

-38000

796000

-21815000

5100000

104749000

19809000

20082000

5073000

237000

685000

2361000

1757000

34939000

34900000

407000

58000

108000

54941000

32383000

9762000

9072000

9000000

58151000

1316000

23435000

2306000

2617000

13221000

5298000

2800000

77586000

4975000

3029000

10165000

5394000

205000

-88664000

-102923000

1625000

40000

5600000

553000

224000

5.00

5417000

2533000

2884000

789000

464000

325000

466000

262000

204000

789000

1071000

566000

505000

530000

276000

254000

1071000

883904

3308135

27991000

24391000

17468000

7628000

2922337

10000000

5478000

15058546

19374909

20114608

20627244

The condensed balance sheet as of December 31, 2011 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, 2011.