Consolidated Statement of Cash Flows - USD ($) $ in Thousands	2 Months Ended	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net loss	$ (1,657)	$ (143,255)	$ (83,440)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation	1,434	11,583	8,717
Depreciation	0	243	61
Amortization of debt discount and issuance costs	0	662	0
Acquisition of in-process research and development	0	0	13,117
Changes in the fair value of the Takeda warrant liability	0	0	27,518
Foreign currency translation adjustment	0	(116)	140
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	0	(1,918)	(3,221)
Deferred tax assets	0	208	(208)
Income tax receivable	0	(895)	(105)
Other assets	0	(3,065)	0
Accounts payable	0	1,249	3,329
Interest payable	0	282	0
Accrued expenses	223	18,287	11,755
Due to Roivant Sciences Ltd., Roivant Sciences, Inc. and Roivant Sciences GmbH	0	(1,070)	4,009
Deferred rent	0	295	113
Deferred interest payable	0	255	0
Net cash used in operating activities	0	(117,255)	(18,215)
Cash flows from investing activities:
Purchase of furniture and equipment		(604)	(967)
Net cash used in investing activities		(604)	(967)
Cash flows from financing activities:
Cash proceeds from issuance of common shares in initial public offering, net of underwriting discount	0	0	202,275
Initial public offering costs paid	0	0	(2,311)
Cash proceeds from debt financings, net of financing costs	0	43,751	0
Cash proceeds from issuance of common shares to NovaQuest, net of issuance costs	0	1,857	0
Cash capital contribution from Roivant Sciences Ltd.	0	0	1,035
Settlement of Roivant Sciences Ltd. common shares subscribed	0	1	0
Stock option exercises	0	36	0
Due to Roivant Sciences Ltd. and Roivant Sciences, Inc. for amounts paid on behalf of the Company	0	0	(979)
Net cash provided by financing activities	0	45,645	200,020
Net change in cash	0	(72,214)	180,838
Cash—beginning of period	0	180,838	0
Cash—end of period	0	108,624	180,838
Non-cash investing and financing activities:
Acquisition of in-process research and development	0	0	13,117
Warrants issued to Hercules	0	789	0
Supplemental disclosure of cash paid:
Income taxes	0	900	240
Interest	$ 0	$ 845	$ 0