Share-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2017

Schedule of assumptions that the Company used to determine the grant-date fair value of stock options granted

	Three Months Ended March 31, 2017
Risk-free interest rate	1.96		%
Expected term (in years)	5.51
Expected volatility	70.46		%
Expected dividend yield	0		%
Exercise price	$	9.38
Fair value of common share	$	8.68

Summary of stock option activity

				Weighted
		Weighted		Average
		Average		Remaining		Aggregate
	Number of	Exercise		Contractual		Intrinsic
	Shares	Price		Term		Value
				(in years)
Outstanding as of December 31, 2016	3,864,425	$	3.61	9.21		$	15,991
Granted	480,919	9.37
Exercised	—	—
Forfeited	—	—
Outstanding as of March 31, 2017	4,345,344	$	4.24	$	9.18	$	28,578
Options exercisable as of March 31, 2017	2,442,114	$	3.02	$	8.17	$	19,051
Options unvested as of March 31, 2017	1,903,230	$	5.81	$	8.82	$	9,527

Summary of classification of share-based compensation expense

	Three Months Ended March 31,
	2017		2016
Research and development expenses	$	999	$	335
General and administrative expenses	887		352
	$	1,886	$	687

Non-employees

Schedule of assumptions that the Company used to determine the grant-date fair value of stock options granted

	Three Months Ended March 31, 2017
Risk-free interest rate	2.45		%
Expected term (in years)	10.0
Expected volatility	69.98		%
Expected dividend yield	0		%
Exercise price	$	9.29
Fair value of common share	$	8.68