Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Payments (Tables)

Stock-Based Payments (Tables)

3 Months Ended

Mar. 31, 2017

Summary of status of stock options and changes during the period

A summary of the status of stock options as of December 31, 2016 and March 31, 2017 and changes during the three months ended March 31, 2017 is presented below:


					Aggregate
		Weighted		Remaining	Intrinsic
		Average		Contractual	Value
	Shares	Exercise Price		Life (in years)	(in thousands)
Outstanding at December 31, 2016	2,543,435	$	6.44	8.3	$	14,898
Granted	864,000		10.91
Exercised	(50,508)		2.78
Cancelled	(198,369)		5.17
Outstanding at March 31, 2017	3,158,558	$	7.81	8.2	$	25,554
Exercisable at March 31, 2017	908,893	$	3.74	6.0	$	11,082
Vested and expected to vest at March 31, 2017	3,158,558	$	7.81	8.2	$	25,554

Summary of status of unvested restricted common stock and changes during the period

A summary of the status of unvested restricted common stock as of December 31, 2016 and changes during the three months ended March 31, 2017 is presented below:


		Weighted
		Average Grant
	Shares	Date Fair Value
Unvested at December 31, 2016	4,885	$	0.98
Vested	(1,332)		0.98
Repurchased	—		—
Unvested at March 31, 2017	3,553	$	0.98

Schedule of weighted-average assumptions used in Black-Scholes option-pricing model

The fair value of each stock option granted was estimated on the date of grant using the Black-Scholes option-pricing model based on the following weighted-average assumptions:


	Three Months Ended March 31,
	2017		2016
Weighted-average risk-free interest rate	2.07	%	1.39	%
Expected dividend yield	-	%	-	%
Expected option term	6.07		6.08
Volatility	86.14	%	85.52	%

Summary of stock-based compensation expense for stock options and restricted common stock

The following table summarizes the stock-based compensation expense for stock options and restricted common stock granted to employees and non-employees recorded in the Company’s statements of operations:


	Three Months Ended March 31,
	2017		2016
Research and development	$	330	$	560
General and administrative		554		102
Total stock-based compensation expense	$	884	$	662