Stockholders' Equity

3 Months Ended

Mar. 31, 2012

Stockholders' Equity [Abstract]

Stockholders' Equity

7. Stockholders' Equity

Controlled Equity Offerings

In April 2010, the Company entered into a controlled equity offering sales agreement with Cantor Fitzgerald & Co. ("Cantor"), pursuant to which the Company could issue and sell shares of its common stock having an aggregate offering price of up to $20.0 million from time to time through Cantor acting as agent and/or principal. The Company agreed to pay Cantor a commission of 3.0% of the gross proceeds from each sale. In the three months ended March 31, 2012, the Company sold an aggregate of 88,500 shares of common stock at an average price of approximately $3.08 per share for gross and net proceeds of $0.3 million, after deducting Cantor's commission, which were received in April 2012. Through March 31, 2012, the Company had sold an aggregate of 4,471,783 shares of common stock under this facility at an average price of approximately $4.08 per share for gross proceeds of $18.3 million and net proceeds of $17.7 million, after deducting Cantor's commission. As of March 31, 2012, $1.7 million of common stock remained available to be sold under this facility, subject to certain conditions as specified in the agreement.

In August 2011, the Company entered into an additional controlled equity offering sales agreement with Cantor, pursuant to which the Company may issue and sell shares of its common stock having an aggregate offering price of up to $20.0 million from time to time through Cantor acting as agent and/or principal. The Company agreed to pay Cantor a commission of 3.0% of the gross proceeds from each sale. As of March 31, 2012, no sales had been made under this facility, and $20.0 million of common stock remained available to be sold under this facility, subject to certain conditions as specified in the agreement.