Fair Value Measurements (Tables)

12 Months Ended

Mar. 31, 2019

Fair Value Disclosures [Abstract]

Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis

There were no assets measured at fair value as of March 31, 2018. The following table summarizes these assets (in thousands):

	As of March 31, 2019
	Level 1		Level 2		Level 3		Total Fair Value
Assets:
Money market funds	$	83	$	—	$	—	$	83
Commercial paper	—		126,050		—		126,050
Total assets	$	83	$	126,050	$	—	$	126,133

Schedule of Significant Unobservable Inputs

The Company estimated the fair value of the Warrants using the Black-Scholes model based on the following key assumptions:

	Tranche 1	Tranche 2
Exercise price	$15.06	$18.82
Common share price on date of issuance	$14.39	$18.96
Volatility	73.2%	72.3%
Risk-free interest rate	2.15%	2.78%
Expected dividend yield	—%	—%
Contractual term (in years)	7.00	7.00

The fair value of the Takeda warrant liability as of March 31, 2017 was calculated using the following significant unobservable inputs:

Input	Range or Point Estimate Used
Projected time frame to an equity financing	April 2017
Probability of a successful equity financing	2.0	%
Annualized equity volatility	73.4	%
Risk-free interest rate	0.74	%

Schedule of Changes in Fair Value of Level 3 Warrant Liability

The changes in fair value of the Takeda warrant liability during the years ended March 31, 2018 and 2017 were as follows (in thousands):

Balance at March 31, 2016	$	—
Fair value of the Takeda warrant liability issued	5,377
Changes in the fair value of the Takeda warrant liability, included in net loss	27,518
Settlements	(32,843		)
Balance at March 31, 2017	52
Fair value of the warrant liability issued	—
Changes in the fair value of the warrant liability, included in net loss	—
Settlements	(52		)
Balance at March 31, 2018	$	—