Common Stock and Warrants

12 Months Ended

Dec. 31, 2015

Equity [Abstract]

Common Stock and Warrants

10. Common Stock and Warrants

As of December 31, 2015, the Company had 200,000,000 authorized shares of common stock, $0.001 par value, of which 58,181,715 shares were issued and outstanding. The number of authorized shares of common stock was increased from 100,000,000 at the Company’s 2015 annual shareholders meeting.

As part of the Amended Loan Agreement with Hercules Technology II, L.P. and Hercules Technology III, L.P., affiliates of Hercules Technology Growth (collectively, “Hercules”), on September 24, 2014, the Company issued warrants to the lenders to purchase up to 608,696 shares of the Company’s common stock at an exercise price equal to $1.15 per share to Hercules. All warrants issued during the year remain outstanding as of December 31, 2015.

ATM Sales Agreement

In February 2015, the Company entered into an at-the-market issuance sales agreement with FBR & Co. (formerly MLV & Co. LLC (“FBR”), pursuant to which the Company could issue and sell shares of its common stock from time to time up to an aggregate amount of $17.9 million, at the Company’s option, through FBR as its sales agent. Sales of common stock through FBR may be made by any method that is deemed an “at-the-market” offering as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, including by meansof ordinary brokers’ transactions at market prices, in block transactions or as otherwise agreed by the Company and FBR. Subject to the terms and conditions of the sales agreement between the Company and FBR (the “Sales Agreement”), FBR will use commercially reasonable efforts to sell the common stock based upon the Company’s instructions (including any price, time or size limits or other customary parameters or conditions the Company may impose). The Company is not obligated to make any sales of its common stock under the Sales Agreement. Any shares sold will be sold pursuant to an effective shelf registration statement on Form S-3. The Company will pay FBR a commission of up to 3% of the gross proceeds. The Sales Agreement may be terminated by the Companyat any time.

On May 7, 2015, the Company filed a shelf registration statement on Form S-3 with the SEC, which covers the offering, issuance and sale by the Company of up to $100.0 million of its common stock, preferred stock, debt securities, warrants and/or units (the “2015 Shelf”). The 2015 Shelf was filed to replace the Company’s existing $250.0 million shelf registration statement (the “2012 Shelf”). On May 7, 2015, the Company amended its Sales Agreement with FBR to provide for the offering, issuance and sale by the Company of up to $15.0 million of its common stock under the 2015 Shelf, which replaced the Company’s existing $17.9 million offering that expired along with the expired 2012 Shelf. As of December 31, 2015, the Company has sold approximately 5.9 million shares pursuant to the Sales Agreement, resulting in proceeds of approximately $10.2 million, net of commissions and issuance costs.

Approximately $9.0 million remains available for sale under the Sales Agreement.