Common Stock

6 Months Ended

Jun. 30, 2012

Common Stock [Abstract]

COMMON STOCK

8. COMMON STOCK

The Company has authorized 200,000,000 shares of Common Stock, $0.00001 par value per share, of which 64,693,936 shares were issued and outstanding as of June 30, 2012 and 53,760,471 shares were issued and outstanding as of December 31, 2011.

In February 2012, the Company completed a public offering of Common Stock and issued 9,523,810 shares of Common Stock at a purchase price of $2.10 per common share. The offering raised gross proceeds of approximately $20 million and the Company received net proceeds of approximately $18,207,000 after deducting underwriter discounts and offering expenses.

During the first quarter of 2012, the Company issued 281,691 shares of Common Stock upon the exercise of stock options and received cash proceeds of approximately $20,500.

During the first quarter of 2012, the Company issued 362,400 shares of common stock upon the exercise of warrants, including warrants to purchase 266,123 shares of Common Stock exercised through cashless exercise provisions and warrants to purchase 220,000 shares of Common Stock exercised for cash, providing cash proceeds of approximately $292,000.

During the second quarter of 2012, the Company issued 405,737 shares of Common Stock upon the exercise of stock options and received cash proceeds of approximately $29,500.

During the second quarter of 2012, the Company issued 326,451 shares of common stock upon the exercise of warrants, including warrants to purchase 92,975 shares of Common Stock exercised through cashless exercise provisions and warrants to purchase 277,946 shares of Common Stock exercised for cash, providing cash proceeds of approximately $374,000.

During the second quarter of 2012, the Company issued 18,376 shares of common stock with a fair value of approximately $42,000 to the Company’s 401(k) plan as a matching contribution.