Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Dec. 31, 2018		Dec. 31, 2017	Dec. 31, 2018		Dec. 31, 2017
Operating expenses:
Research and development	$ 58,434	[1]	$ 34,875	$ 163,588	[1]	$ 76,753
General and administrative	10,686	[2]	6,640	29,738	[2]	16,963
Total operating expenses	69,120		41,515	193,326		93,716
Interest expense, net	1,634		904	4,831		904
Other (income) expense, net	(121)		(429)	147		(225)
Loss before income taxes	(70,633)		(41,990)	(198,304)		(94,395)
Income tax (benefit) expense	0		(213)	233		607
Net loss	$ (70,633)		$ (41,777)	$ (198,537)		$ (95,002)
Net loss per common share — basic and diluted (in USD per share)	$ (1.04)		$ (0.70)	$ (3.01)		$ (1.60)
Weighted average common shares outstanding — basic and diluted (in shares)	67,616,419		59,629,486	65,873,779		59,446,140
Research and development
Costs allocated from RSL, RSI, and RSG	$ 41		$ 1,958	$ 2,524		$ 3,061
General and administrative
Costs allocated from RSL, RSI, and RSG	$ 470		$ 1,183	$ 2,644		$ 2,692

[1] Includes $41 and $1,958 of costs allocated from RSL, RSI, and RSG during the three months ended December 31, 2018 and 2017, respectively, and $2,524 and $3,061 of costs allocated from RSL, RSI, and RSG during the nine months ended December 31, 2018 and 2017, respectively. Also includes share-based compensation expense (see Note 9).

[2] Includes $470 and $1,183 of costs allocated from RSL, RSI, and RSG during the three months ended December 31, 2018 and 2017, respectively, and $2,644 and $2,692 of costs allocated from RSL, RSI, and RSG during the nine months ended December 31, 2018 and 2017, respectively. Also includes share-based compensation expense (see Note 9).