Share-based compensation (Tables)

12 Months Ended

Dec. 31, 2021

Share-based compensation

Schedule of share based compensation expense

The Company recorded share-based compensation expense in the following expense categories of its consolidated statements of operations and comprehensive loss (in thousands):

	Year Ended
	December 31,
	2021		2020		2019
Research and development expenses	$	4,974	$	2,603	$	1,286
General and administrative expenses		7,109		3,911		1,797
	$	12,083	$	6,514	$	3,083

Schedule of share option activity

				Weighted
		Weighted		Average	Aggregate
	Number of	Average		Contractual	Intrinsic
	Shares	Exercise Price		Term	Value
				(in years)	(in thousands)
Outstanding as of December 31, 2020	3,736,663	$	10.51	8.54	$	27,553
Granted	1,677,525		23.07	—		—
Exercised	(703,786)		10.21	—		—
Forfeited	(106,916)		18.67	—		—
Outstanding as of December 31, 2021	4,603,486	$	14.97	8.13	$	207,009
Vested and expected to vest as of December 31, 2021	4,603,486	$	14.97	8.13	$	207,009
Options exercisable as of December 31, 2021	2,169,664	$	10.43	7.52	$	108,948

Schedule of assumptions used to determine the fair value of share options granted

	Year Ended
	December 31,
	2021		2020		2019
Risk-free interest rate	0.6	%	1.3	%	2.1	%
Expected volatility	79.8	%	74.8	%	77.9	%
Expected dividend yield	—		—		—
Expected term (in years)	5.98		5.98		5.86