Common Stock

6 Months Ended

Jun. 30, 2011

Common Stock

(10) Common Stock

Reverse Stock Split

On February 2, 2010, the Company’s Board of Directors, and on February 11, 2010, the Company’s stockholders, approved a 1-for-4 reverse stock split of the Company’s common stock. The reverse stock split was effected on February 18, 2010. All share and per share amounts in the condensed consolidated financial statements have been retroactively adjusted for all periods presented to give effect to the reverse stock split, including reclassifying an amount equal to the reduction in par value to additional paid-in capital.

Initial Public Offering

In March 2010, the Company raised $81.0 million in gross proceeds from the sale of 9,000,000 shares of its common stock in an initial public offering at $9.00 per share. The net offering proceeds after deducting approximately $3.1 million in offering related expenses and underwriters’ discounts were approximately $72.2 million. In March 2010, the underwriters of the initial public offering exercised their option to purchase, and in April 2010, the Company closed the sale to such underwriters of, an additional 968,539 shares of common stock at $9.00 per share resulting in additional net proceeds to the Company of approximately $8.1 million. All outstanding shares of the Company’s convertible preferred stock were converted into 18,979,155 shares of common stock upon the completion of the initial public offering.

In connection with the initial public offering, the Company reclassified its liability related to preferred stock warrants into additional paid-in capital as a result of the conversion of warrants to purchase convertible preferred stock into warrants to purchase common stock.

Private Placement

On October 28, 2010, the Company entered into a definitive agreement with respect to the private placement of 4.5 million shares of its unregistered common stock at $13.50 per share to a group of institutional and accredited investors. The Company completed the private placement on November 3, 2010, resulting in approximately $56.6 million in net proceeds to the Company.

On May 31, 2011, the Company entered into a definitive agreement with respect to the sale of 438,340 shares of its unregistered common stock at $17.11 per share to Johnson & Johnson Development Corporation. The Company completed the private placement on May 31, 2011, resulting in approximately $7.5 million in net proceeds to the Company.

Follow-on Offering

In June 2011, the Company raised $100.6 million in gross proceeds from the sale of 5,750,000 shares of its common stock in a follow-on public offering at $17.50 per share. In June 2011, the underwriters of the public offering exercised their option to purchase an additional 602,119 shares of common stock at $17.50 per share resulting in additional gross proceeds to the Company of approximately $10.5 million. The combined net offering proceeds after deducting approximately $6.9 million in offering related expenses and underwriters’ discounts and commissions were approximately $104.2 million.