Share-Based Compensation (Tables)

12 Months Ended

Mar. 31, 2020

Share-based Payment Arrangement [Abstract]

Schedule of Weighted Average Fair Value Assumptions

The Company estimated the fair value of each stock option on the date of grant using the Black-Scholes option-pricing model applying the weighted average assumptions in the following table:

	Years Ended March 31,
	2020		2019		2018
Expected common share price volatility	69.5	%	71.6	%	74.4	%
Expected risk free interest rate	2.05	%	2.78	%	2.04	%
Expected term, in years	6.17		6.23		6.22
Expected dividend yield	—	%	—	%	—	%

Summary of Stock Option Activity

A summary of stock option activity and data under the Company’s 2016 Plan for the periods presented is as follows:

	Number of Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)	Aggregate Intrinsic Value (in thousands)
Options outstanding at March 31, 2017	1,525,857		$	5.06	9.52	$	10,255
Granted	2,338,116		$	12.50
Exercised	(15,195	)	$	2.38
Forfeited	(299,373	)	$	6.64
Options outstanding at March 31, 2018	3,549,405		$	9.84	9.02	$	40,557
Granted	2,246,410		$	21.36
Exercised	(154,494	)	$	8.41
Forfeited	(244,856	)	$	14.59
Options outstanding at March 31, 2019	5,396,465		$	14.46	8.51	$	50,878
Granted	2,992,200		$	11.57
Exercised	(124,097	)	$	7.59
Forfeited	(541,266	)	$	17.60
Options outstanding at March 31, 2020	7,723,302		$	9.25	8.08	$	4,146
Options vested and expected to vest at March 31, 2020	7,723,302		$	9.25	8.08	$	4,146
Options exercisable at March 31, 2020	3,009,080		$	8.13	7.30	$	3,686

Additional information regarding options is set forth below (in thousands, except per share data).

	Years Ended March 31,
	2020		2019		2018
Intrinsic value of options exercised	$	1,036	$	2,167	$	181
Grant date fair value of options vested	$	2,112	$	11,409	$	5,831
Weighted-average grant date fair value per share of options granted	$	11.54	$	14.10	$	8.35

Summary of Restricted Share Awards and Restricted Stock Units Activity

A summary of restricted stock award (“RSA”) and restricted stock unit (“RSU”) activity and data under the Company’s 2016 Plan for the periods presented is as follows:

	Number of shares		Weighted Average Grant Date Fair Value
Unvested balance at March 31, 2017	1,128,222		$	5.10
Granted	579,111		$	14.10
Vested	(493,598	)	$	5.10
Unvested balance at March 31, 2018	1,213,735		$	9.39
Granted	29,700		$	17.28
Vested	(287,369	)	$	5.21
Unvested balance at March 31, 2019	956,066		$	10.90
Granted	724,554		$	7.98
Vested	(295,090	)	$	5.56
Forfeited	(105,218	)	$	7.98
Unvested balance at March 31, 2020	1,280,312		$	10.71

Schedule of Share-based Compensation Expense

Share-based compensation expense was as follows (in thousands):

	Years Ended March 31,
	2020		2019		2018
Share-based compensation expense recognized as:
R&D expenses	$	14,524	$	7,161	$	3,674
G&A expenses	25,727		11,535		7,909
Total	$	40,251	$	18,696	$	11,583