Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cash Flows From Operating Activities
Net loss	$ (19,652)	$ (27,354)
Adjustments to reconcile net loss to net cash used in operating activities:
(Gain) loss on disposal of fixed assets	63	0
Depreciation and amortization	824	962
Stock-based compensation	3,911	5,600
Increase (decrease) in cash resulting from changes in:
Accounts receivable	336	(527)
Grants receivable	21	(260)
Inventory	(207)	(55)
Prepaid expenses and other assets	637	253
Accounts payable	183	(719)
Accrued expenses	(1,185)	(1,293)
Deferred revenue	(107)	260
Deferred rent	(122)	(113)
Net cash used in operating activities	(15,298)	(23,246)
Cash Flows From Investing Activities
Purchases of fixed assets	(37)	(90)
Proceeds from disposals of fixed assets	3	0
Purchases of intangible assets	0	(70)
Net cash used in investing activities	(34)	(160)
Cash Flows From Financing Activities
Proceeds from issuance of common stock and exercise of warrants, net	6,916	7,243
Employee taxes paid related to net share settlement of equity awards	(136)	(74)
Proceeds from exercise of stock options	50	826
Net cash provided by financing activities	6,830	7,995
Effect of currency exchange rate changes on cash and cash equivalents	0	(2)
Net decrease in cash, cash equivalents, and restricted cash	(8,502)	(15,413)
Cash, cash equivalents, and restricted cash at beginning of period	43,853	62,878
Cash, cash equivalents, and restricted cash at end of period	35,351	47,465
Reconciliation of cash, cash equivalents, and restricted cash to the condensed consolidated balance sheets
Cash and cash equivalents	35,224	47,338
Restricted cash	127	127
Cash, cash equivalents, and restricted cash at end of period	35,351	47,465
Supplemental Disclosure of Cash Flow Information:
Income taxes paid	$ 3	$ 23