Stock Option and Incentive Plans (Tables)

12 Months Ended

Dec. 31, 2014

Stock Option and Incentive Plans

Schedule of total compensation cost recognized for all stock option awards in the statements of operations

Total compensation cost recognized for all stock option awards in the statements of operations is as follows (in thousands):

	Year Ended December 31,
	2014		2013
Research and development	$	137	$	15
General and administrative	561		221
Total stock-based compensation expense	$	698	$	236

Summary of activity for all option

A summary of activity for the years ended December 31, 2014 and 2013 is presented below (in thousands, except share and per share amounts):

	Shares		Weighted- Average Exercise  Price Per Share		Aggregate Intrinsic Value
Outstanding—December 31, 2012	689,663		—
Granted	589,719		—
Exercised	(15,515	)	1.04
Forfeited	(170,659	)	—
Outstanding—December 31, 2013	1,093,208		1.04
Granted	700,000		8.99
Exercised	(122,634	)	1.04
Outstanding—December 31, 2014	1,670,574		$	4.37	$	10,357
Exercisable—December 31, 2014	764,338		$	1.75	$	6,740
Exercisable and Expected to vest—December 31, 2014	1,670,574		$	4.37	$	10,357

Schedule of weighted-average assumptions estimated at the date of grant using the Black-Scholes option pricing model for weighted-average grant date fair value of the options granted to employees

	2014	2013
Expected stock price volatility	77.66 — 86.08%	103.9 - 118.0%
Expected term of options	5.5 — 6.06 years	5 - 6.25 years
Risk-free interest rate	1.75 — 1.98%	0.84 - 1.75%
Expected annual dividend yield	0%	0%

Schedule of expense is expected to be recognized

As of December 31, 2014, there was $4.1 million of total unrecognized compensation expense related to unvested stock options granted under the 2005 Plan and 2014 Plan. That expense is expected to be recognized in the years ended as follows, in thousands:

December 31, 2015	$	1,448
December 31, 2016	1,302
December 31, 2017	929
December 31, 2018	403
	$	4,082