Share-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2020

Share-Based Compensation

Schedule of share option activity under the Plans

		Weighted
	Number of	Average
	Shares	Fair Value
Outstanding as of December 31, 2019	8,491,734	$	7.68
Granted	1,455,250	$	10.74
Exercised	(643,867)	$	2.50
Forfeited	(234,919)	$	10.89
Cancelled	(77,326)	$	16.72
Outstanding as of March 31, 2020	8,990,872	$	8.39
Options exercisable as of March 31, 2020	3,176,450	$	8.26
Options unvested as of March 31, 2020	5,814,422	$	9.63

Schedule of stock option valuation assumptions presented on weighted-average basis

	Three Months Ended
	March 31,
	2020		2019
Risk-free interest rate	0.82	%	2.58	%
Expected term (in years)	6.25		6.25
Expected volatility	79.83	%	78.18	%
Expected dividend yield	0	%	0	%

Schedule of restricted share activity

		Weighted
		Average
	Number of	Grant Date
	Shares	Fair Value
Unvested RSUs as of December 31, 2019	328,296	$	12.93
Granted	—	$	—
Vested	—	$	—
Forfeited	(26,253)	$	12.93
Unvested RSUs as of March 31, 2020	302,043	$	12.93

Schedule of share-based compensation expense was classified in the consolidated statements of operations and comprehensive loss

	Three Months Ended
	March 31,
	2020		2019
Research and development expenses	$	1,769	$	1,187
General and administrative expenses		2,440		1,706
	$	4,209	$	2,893