Stock-based compensation (Tables)

6 Months Ended

Jun. 30, 2022

Share-based Payment Arrangement [Abstract]

Schedule of stock-based compensation expense

Stock-based compensation expense for the three and six months ended June 30, 2022 and 2021 was classified in the Company’s condensed consolidated statement of operations and comprehensive loss as follows (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Stock-based compensation expense:
Research and development	$	3,776	$	1,940	$	7,388	$	3,111
General and administrative	4,372		3,288		9,698		5,962
Total stock-based compensation expense	$	8,148	$	5,228	$	17,086	$	9,073

Summary of stock option activity

The following table summarizes the stock option activity under the Company’s equity awards plans for the six months ended June 30, 2022:

	Number of Stock Options	Weighted-Average Exercise Price
Outstanding as of December 31, 2021	5,983,425	$	22.33
Granted	1,962,600	20.58
Exercised	(123,288)	4.78
Cancelled or forfeited	(766,824)	21.77
Outstanding as of June 30, 2022	7,055,913	$	22.21
Options exercisable as of June 30, 2022	2,152,611	$	20.92
Vested and expected to vest as of June 30, 2022	7,055,913	$	22.21

Summary of RSU activity

The following table summarizes the restricted stock unit activity under the Company’s equity awards plans for the six months ended June 30, 2022:

	Shares	Weighted-Average Grant Date Fair Value
Outstanding as of December 31, 2021	—	$	—
Granted	563,500	25.47
Vested	(64,383)	25.01
Forfeited	(3,300)	31.58
Outstanding as of June 30, 2022	495,817	$	25.49