Share-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2021

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Summary of Stock Option Activity

The following table summarizes stock option activity under all equity plans (excluding RSUs) during the three months ended March 31, 2021:

	Number of Shares			Weighted Average Exercise Price		Weighted Average Contractual Term		Aggregate Intrinsic Value
						(in years)		(in thousands)
Outstanding as of December 31, 2020		3,682,233		$	9.10		7.84	$	37,881
Granted		1,019,365			18.90		—		—
Exercised		(11,514	)		7.58		—		—
Forfeited or cancelled		(106,944	)		13.41		—		—
Outstanding as of March 31, 2021		4,583,140		$	11.18	8.06		$	20,727
Outstanding as of March 31, 2021 - vested and    expected to vest		4,583,140		$	11.18	8.06		$	20,727
Exercisable at March 31, 2021		2,097,721		$	8.11		6.90	$	13,880

Summary of Share-Based Compensation Expense

The Company recorded share-based compensation expense related to incentive stock options, nonqualified stock options, stock grants, and stock-based awards in the following expense categories of its consolidated statements of operations and comprehensive loss (in thousands):

	Three Months Ended March 31,
	2021		2020
Research and development expenses	$	840	$	496
General and administrative expenses		1,169		614
Total	$	2,009	$	1,110

Performance-based Vesting Criteria [Member]

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Summary of Activity of Options and RSUs of Performance-Based Options

The following table summarizes the activity of options and RSUs under the 2017 Plan containing performance-based vesting criteria during the three months ended March 31, 2021:

	Number of Performance Based Option Shares			Number of Performance Based RSU Shares
Outstanding as of December 31, 2020		63,107			30,561
Granted		-			-
Exercised		-			-
Forfeited or cancelled		(63,107	)		(30,561	)
Outstanding as of March 31, 2021		-			-