Stock-based compensation (Tables)

3 Months Ended

Mar. 31, 2021

Summary of Stock Options

Stock option activity during the three months ended March 31, 2021 is as follows:

	Time-based options
	Shares subject to options			Weighted- average exercise price		Weighted- average remaining contractual term (years)		Aggregate Intrinsic Value
Outstanding as of January 1, 2021		5,488,148		$	11.19	9.57		$	90,335
Granted		59,500		$	26.46
Exercised		(26,207	)	$	3.50			$	92
Cancelled		(5,718	)	$	3.01
Outstanding as of March 31, 2021		5,515,723		$	11.40		9.35	$	62,548
Options vested and expected to vest as of March 31, 2021		5,460,481		$	11.48		9.35	$	61,485
Options vested and exercisable as of March 31, 2021		752,171		$	6.36		8.98	$	12,321

Summary of Stock Based Compensation Expense Was Allocated

Stock-based compensation expense was allocated as follows for the three months ended March 31, 2021 and 2020:

	March 31, 2021		March 31, 2020
Research and development	$	1,709	$	172
General and administrative		1,047		159
Total	$	2,756	$	331

Restricted Stock [Member]

Summary of Stock Options

The following table summarizes the Company’s restricted common stock activity for the three months ended March 31, 2021:

	Number of Awards			Weighted- Average Grant Date Fair Value		Aggregate Fair Value
Issued and unvested as of January 1, 2021		408,411			1.15		470
Restricted stock awards granted		—			—		—
Restricted stock awards vested		(104,700	)		0.86		(90	)
Issued and unvested as of March 31, 2021		303,711			1.25		380