STOCKHOLDER'S EQUITY

3 Months Ended

Mar. 31, 2014

Stockholders Equity Note [Abstract]

Stockholders Equity Note Disclosure

9. STOCKHOLDER’S EQUITY

On March 10, 2014, we completed a follow-on public offering of 1.6 million shares of our common stock at a public offering price of $31.00 per share (the “March 2014 Offering”). We received gross proceeds of $50.0 million, or net proceeds of $46.7 million after deducting costs of $3.3 million, including the underwriters’ fees and commissions, as well as expenses directly related to the March 2014 Offering. The number of shares sold in the March 2014 Offering includes the exercise in full by the underwriters of their option to purchase an additional 0.2 million shares of common stock.

In January 2014, warrants to purchase an aggregate of 20 thousand shares of common stock were exercised at $9.00 per share. During the three months ended March 31, 2014, warrants to purchase an aggregate of 112 thousand shares of common stock expired unexercised.