Stockholders' Equity

3 Months Ended

Mar. 31, 2016

Equity [Abstract]

Stockholders' Equity

8. Stockholders’ Equity

Controlled Equity Offerings

In August 2011, the Company entered into a Controlled Equity Offering^SM sales agreement (the “Sales Agreement”), with Cantor Fitzgerald & Co. (“Cantor”), as agent and/or principal, pursuant to which the Company could issue and sell shares of its common stock having an aggregate gross sales price of up to $20.0 million. In April 2013, the Sales Agreement was amended to provide for an increase of $30.0 million in the aggregate gross sales price under the Sales Agreement. In March 2015, the Sales Agreement was further amended to provide for an additional increase of $30.0 million in the aggregate gross sales price under the Sales Agreement. The Company will pay Cantor a commission of up to 3.0% of the gross proceeds from any common stock sold through the Sales Agreement, as amended.

During the three months ended March 31, 2016, no shares of common stock were sold under the Sales Agreement. As of March 31, 2016, $18.2 million of common stock remained available to be sold under this facility, subject to certain conditions as specified in the Sales Agreement, as amended.