Warrants

6 Months Ended

Jun. 30, 2012

Warrants [Abstract]

Warrants

(9) Warrants

(a) Warrant to Purchase Common Stock

On September 27, 2007, the Company granted ORIX a warrant for 75,000 shares of Common Stock at a purchase price of $8.20 per share in connection with a debt facility that was repaid in December 2009.

The warrant is exercisable, in whole or in part, for a period of seven years through September 26, 2014. The warrant does not entitle the holder to any voting rights or other rights as a stockholder of the Company prior to exercise. This warrant is classified as equity.

(b) Lender Warrant

On May 23, 2005, the Company entered into a Senior Loan and Security Agreement, or Hercules Debt, with Hercules. On September 27, 2007, the Company repaid the loan to Hercules. In connection with the Hercules Debt financing, the Company granted Hercules a warrant to purchase 423,529 shares of Series C Redeemable Preferred Stock at a purchase price of $4.25 per share. The warrant is exercisable, in whole or in part, for a period ending November 2013. Upon the automatic conversion of the Company’s preferred stock into common stock in connection with the closing of the Company’s IPO on May 15, 2012, the Lender Warrant became exercisable for 211,764 shares of common stock at a purchase price of $8.50 per share. The Company performed the final re-measurement of the Lender Warrant at the closing date and the Lender Warrant was then reclassified from liability to equity. As the warrant is no longer exercisable into shares of redeemable preferred stock but into shares of common stock which is non-redeemable, the Company will no longer record any mark-to-market changes in the fair value of the warrant in the statements of operations. The fair value of the Lender Warrant at the final re-measurement date was approximately $0.7 million. The Company recorded a mark-to-market gain of $0.4 million for the three and six months ended June 30, 2012. The Company recorded a mark-to-market gain of $0.1 million and a loss of $0.1 million for the three and six months ended June 30, 2011, respectively. This revaluation is included in other income (expense) as separate line item entitled “Gain (loss) on revaluation of warrants.” The warrant does not entitle the holder to any voting rights or other rights as a stockholder of the Company prior to exercise.

(c) Investor Warrants

On December 28, 2009, in connection with the Company entering into certain convertible note agreements with several existing Preferred Stockholders, the Company granted to the instrument holders warrants, or Investor Warrants, to purchase Series E Preferred Stock (later amended to Series E-1 Preferred Stock).

Upon the automatic conversion of the Company’s preferred stock into common stock in connection with the closing of the Company’s IPO on May 15, 2012, the Investor Warrants became exercisable for 4,366,803 shares of common stock.