Stock-based compensation (Tables)

6 Months Ended

Jun. 30, 2015

Stock-based compensation

Summary of the Company's stock option activity

	Shares		Weighted- Average  Exercise Price		Weighted- Average  Remaining  Contractual  Term (years)	Agregate  Intrinsic  Value (in  000’s)
Outstanding at December 31, 2014	1,226,140		$	4.14	8.15	$	6,579
Granted	360,530		10.64
Exercised	(25,045	)	2.05
Cancelled or forfeited	(27,424	)	4.09
Outstanding at June 30, 2015	1,534,201		$	5.70	8.16	$	9,980
Exercisable at June 30, 2015	690,832		$	3.06	7.02	$	6,318
Vested or expected to vest at June 30, 2015	1,410,518		$	5.46	8.06	$	9,524

Schedule of stock-based compensation expense

Total stock-based compensation expense is recognized for stock options granted to employees and non-employees and has been reported in the Company’s statements of operations as follows (in thousands):

	Three months ended June 30,				Six months ended June 30,
	2015		2014		2015		2014
Research and development	$	165	$	109	$	333	$	189
General and administrative	189		119		322		184
Total	$	354	$	228	$	655	$	373