Stock-based compensation (Tables)

12 Months Ended

Mar. 31, 2020

Stock-based Compensation

Summary of stock option activity

		Weighted		Weighted Average
	Number of	Average		Contractual Term	Aggregate
	Shares	Exercise Price		(Years)	Intrinsic Value
Outstanding as of March 31, 2019	3,721,784	$	7.14	8.61	$	30,150
Granted	1,637,035		15.07	9.21
Exercised	(207,673)		2.65
Cancelled	(186,765)		11.48
Outstanding as of March 31, 2020	4,964,381	$	9.78	8.02	$	15,344
Options exercisable as of March 31, 2019	1,278,330	$	2.51	7.75	$	16,249
Options exercisable as of March 31, 2020	2,117,721	$	5.66	7.20		11,733

Schedule of stock-based compensation expense

	Year Ended
	March 31,
	2020		2019		2018
Research and development	$	3,689	$	1,488	$	335
General and administrative		4,052		1,242		477
	$	7,741	$	2,730	$	812

Employees stock options

Stock-based Compensation

Schedule of assumptions used to determine the grant-date fair value of stock options granted

	Year Ended
	March 31,
	2020		2019		2018
Risk-free interest rate	2.12	%	2.81	%	2.01	%
Expected term (in years)	6.0		6.1		6.0
Expected volatility	71.4	%	62.0	%	75.0	%
Expected dividend yield	0	%	0	%	0	%

Non Employee Stock Option Member

Stock-based Compensation

Schedule of assumptions used to determine the grant-date fair value of stock options granted

	Year Ended
	March 31, 2018
Risk-free interest rate	2.29	%
Expected term (in years)	10.0
Expected volatility	75.0	%
Expected dividend yield	0	%