Share-based compensation (Tables)

3 Months Ended

Mar. 31, 2020

Share-based compensation

Schedule of share based compensation expense

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

	Three Months Ended
	March 31,
	2020		2019
Research and development expenses	$	675	$	108
General and administrative expenses		1,446		168
	$	2,121	$	276

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, 2019	2,634,346	$	9.57	9.04	$	2,868
Granted	1,030,361		10.17	—		—
Exercised	(1,071)		1.47	—		—
Forfeited	(8,748)		8.67	—		—
Outstanding as of March 31, 2020	3,654,888	$	9.74	9.17	$	14,973
Vested and expected to vest as of March 31, 2020	3,654,888	$	9.74	9.17	$	14,973
Options exercisable as of March 31, 2020	984,491	$	7.71	8.79	$	5,993

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

	Three
	Months
	Ended
	March 31,
	2020		2019
Risk-free interest rate	1.6	%	2.7	%
Expected volatility	73.7	%	79.6	%
Expected dividend yield	—		—
Expected term (in years)	5.95		6.07