Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash Flows From Operating Activities
Net loss	$ (2,769)	$ (6,323)
Adjustments to reconcile net loss to net cash used in operating activities:
Gain on disposal of fixed assets	(6)	(1)
Depreciation and amortization	4	205
Stock-based compensation	925	1,220
Increase (decrease) in cash resulting from changes in:
Accounts receivable	27	(35)
Grants receivable	0	(44)
Inventory	0	(16)
Prepaid expenses and other assets	224	360
Accounts payable	(610)	(75)
Accrued expenses	(365)	(1,142)
Deferred revenue	0	7
Operating lease right-of-use assets and liabilities, net	0	(91)
Net cash used in operating activities	(2,570)	(5,935)
Cash Flows From Investing Activities
Proceeds from disposals of fixed assets	2	1
Net cash provided by investing activities	2	1
Cash Flows From Financing Activities
Proceeds from issuance of common stock and exercise of warrants, net	0	4,996
Employee taxes paid related to net share settlement of equity awards	(1)	(52)
Net cash provided by (used in) financing activities	(1)	4,944
Net decrease in cash, cash equivalents, and restricted cash	(2,569)	(990)
Cash, cash equivalents, and restricted cash at beginning of period	27,356	36,556
Cash, cash equivalents, and restricted cash at end of period	24,787	35,566
Reconciliation of cash, cash equivalents, and restricted cash to the condensed consolidated balance sheets
Cash and cash equivalents	24,787	35,487
Restricted cash	0	79
Cash, cash equivalents, and restricted cash at end of period	24,787	35,566
Supplemental Disclosure of Cash Flow Information:
Receivable related to fixed asset sales	5	0
Assets held for sale	1	0
Income taxes paid	$ (2)	$ 0