8.	Common Stock and Warrant Liability

(a)

2015 Public Offering of Common Stock

On February 25, 2015, the Company entered into an underwriting agreement with Cowen and Company, LLC, or Cowen, acting for itself and as representative of the named underwriters, relating to an underwritten public offering of 21,818,181 shares of the Company’s common stock. The offering price to the public was $2.75 per share, and the underwriters agreed to purchase the shares from the Company pursuant to the underwriting agreement at a price of $2.585 per share. Under the terms of the underwriting agreement, the Company granted the underwriters an option, exercisable for 30 days, to purchase up to an additional 3,272,727 shares of common stock at the public offering price per share less the underwriting discounts and commissions. The underwriters exercised this option in full on February 25, 2015. On March 2, 2015, the Company completed the public offering of 25,090,908 shares of common stock. The Company received net proceeds from the sale of the shares, after deducting the underwriting discounts and commissions and estimated offering expenses, of $64,619,407.

(b)

2010 Registered Direct Offering

On January 27, 2010, the Company completed a registered direct offering of 6,449,288 units with each unit consisting of (i) one share of the Company’s common stock and (ii) one warrant to purchase 0.25 of one share of common stock at a purchase price of $2.52 per unit. The Company received net proceeds from the sale of the units, after deducting offering expenses, of approximately $14,942,000.

In connection with this offering, the Company issued warrants to purchase an aggregate of 1,612,322 shares of common stock. As of December 31, 2014, warrants to purchase 238,805 shares of the Company’s common stock had been exercised, and warrants to purchase an aggregate of 1,373,517 shares of common stock were outstanding. All outstanding warrants expired on January 27, 2015 pursuant to the terms of the warrants. Due to the original terms, the warrants were deemed to be a liability and the Company revalued the warrants at each reporting period, with change in fair value of the warrant liability recognized in the Consolidated Statement of Operations and Comprehensive Loss. The Company recorded other income of $67,910 and $716,786 for the three and nine months ended September 30, 2014, respectively. The Company did not recognize any other income or expense associated with these warrants during the three and nine months ended September 30, 2015.

(c)

2015 Sales Agreement

On July 2, 2015, the Company entered into a sales agreement with Cowen, pursuant to which the Company may sell from time to time up to $30,000,000 of the Company’s common stock through an “at-the-market” equity offering program under which Cowen will act as sales agent. Subject to the terms and conditions of the sales agreement, Cowen may sell the common stock by methods deemed to be an “at-the-market” offering as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, including sales made directly on the NASDAQ Global Market, on any other existing trading market for the common stock or to or through a market maker other than on an exchange. In addition, with the Company’s prior written approval, Cowen may also sell the common stock by any other method permitted by law, including in negotiated transactions. Cowen will use its commercially reasonable efforts consistent with its normal trading and sales practices and applicable state and federal laws, rules and regulations and the rules of the NASDAQ Global Market to sell on the Company’s behalf all of the shares requested to be sold by the Company. The Company has no obligation to sell any of the common stock under the sales agreement. Either the Company or Cowen may at any time suspend solicitations and offers under the sales agreement upon notice to the other party. The sales agreement may be terminated at any time by either the Company or Cowen upon written notice to the other party as specified in the sales agreement. The aggregate compensation payable to Cowen shall be 3% of the gross sales price of the common stock sold by Cowen pursuant to the sales agreement. In addition, the Company has agreed to reimburse a portion of the expenses of Cowen in connection with the offering of $16,000. Each party has agreed in the sales agreement to provide indemnification and contribution against certain liabilities, including liabilities under the Securities Act, subject to the terms of the sales agreement. The shares to be sold under the sales agreement, if any, may be issued and sold pursuant to the currently-effective universal shelf registration statement on Form S-3 that the Company filed with the Securities and Exchange Commission on July 2, 2015. The Company did not sell any shares of common stock under this sales agreement during the three or nine months ended September 30, 2015.