Stock-Based Compensation

3 Months Ended

Mar. 31, 2013

Stock-Based Compensation

Stock-Based Compensation

4. Stock-Based Compensation

The Company maintains several equity compensation plans, including the 2012 Omnibus Incentive Plan (the “2012 Incentive Plan”), the 2010 Stock Incentive Plan (the “2010 Incentive Plan”), and the 2012 Employee Stock Purchase Plan (the “2012 ESPP”).

On April 27, 2012, the stockholders of the Company approved the 2012 Incentive Plan, which had been previously adopted by the board of directors. Upon effectiveness of the 2012 Incentive Plan, the Company ceased making awards under the 2010 Incentive Plan. The 2012 Incentive Plan allows the Company to grant awards for up to 1,428,571 shares of common stock plus the number of shares of common stock available for grant under the 2010 Incentive Plan as of the effectiveness of the 2012 Incentive Plan (which was an additional 6,857 shares) plus that number of shares of common stock related to awards outstanding under the 2010 Incentive Plan which terminate by expiration, forfeiture, cancellation, cash settlement or otherwise.  Each year starting with 2014, the number of shares available for grants of awards under the 2012 Incentive Plan will be increased automatically on January 1 by a number of shares of common stock equal to the lesser of 4% of the shares of common stock outstanding at such time or the number of shares determined by the Company’s board of directors. Awards under the 2012 Incentive Plan may include the following award types: stock options, which may be either incentive stock options or nonqualified stock options; stock appreciation rights; restricted stock; restricted stock units; dividend equivalent rights; performance shares; performance units; cash-based awards; other stock-based awards, including unrestricted shares; or any combination of the foregoing.  As of March 31, 2013, the Company has granted stock options covering a total of 1,044,004 shares of common stock under the 2012 Incentive Plan and the exercise price of each option has been equal to the closing price of a share of the Company’s common stock on the grant date or the fair value as determined by the board of directors on the grant date. In addition, as of March 31, 2013, no options have been exercised and 7,856 options have been cancelled under the 2012 Incentive Plan.

Prior to the approval of the 2012 Incentive Plan, the Company granted equity awards under the 2010 Incentive Plan.  As a result of the approval of the 2012 Incentive Plan, in April 2012 the Company ceased making awards under the 2010 Incentive Plan.  Any shares subject to outstanding awards granted under the 2010 Incentive Plan that remained available at that time or that expire or terminate for any reason prior to exercise have been added to the total number of shares available for issuance under the 2012 Incentive Plan. Under the 2010 Incentive Plan, the Company was authorized to grant equity awards up to an aggregate of 1,981,130 shares of common stock.  As of March 31, 2013, a total of 1,785,703 options and 188,570 restricted stock awards have been granted under the 2010 Incentive Plan.  In addition, as of March 31, 2013, 33,440 options have been exercised and 5,000 options have been cancelled under the 2010 Incentive Plan.

Stock-based compensation expense as reflected in the Company’s condensed consolidated statements of operations and comprehensive loss was as follows (in thousands):

					The Period from
					March 26, 2010
	Three Months Ended March 31,				(Inception) to March 31,
	2012		2013		2013
Research and development	$	56	$	332	$	922
General and administrative	150		438		1,956
Total stock-based compensation expense	$	206	$	770	$	2,878

A summary of the Company’s restricted stock activity and related information is as follows:

			Weighted-average
			fair value
	Shares		per share
Unvested at December 31, 2012	349,334		$	0.15
Granted	—		—
Vested	(62,010	)	0.10
Forfeited	—		—
Unvested at March 31, 2013	287,324		$	0.16

A summary of the Company’s stock option activity and related information is as follows:

	Shares		Weighted-average exercise price per share
Outstanding at December 31, 2012	2,134,185		$	5.52
Granted	668,650		24.15
Exercised	(14,424	)	3.41
Cancelled	(5,000	)	1.33
Outstanding at March 31, 2013	2,783,411		$	10.02

At March 31, 2013, there was less than $0.1 million and $16.9 million of total unrecognized compensation cost related to unvested restricted stock and unvested stock options, respectively.  As of March 31, 2013, the Company expects to recognize these costs over remaining weighted-average periods of 1.8 years and 3.1 years, respectively.

On June 6, 2012, the board of directors adopted the 2012 ESPP, and the stockholders approved it on June 18, 2012, to be effective in connection with the closing of the Company’s initial public offering. A total of 275,000 shares of common stock have been reserved for future issuance under the 2012 ESPP pursuant to purchase rights granted to the Company’s employees or to employees of the Company’s designated subsidiaries.  The first offering period under the 2012 ESPP began on January 1, 2013, and the Company has recognized approximately $13,000 in related stock compensation expense through March 31, 2013.