Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash Flows From Operating Activities
Net loss	$ (10,102)	$ (8,767)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	326	251
Change in fair value of warrant liabilities	0	5
Stock-based compensation	2,052	1,429
Increase (decrease) in cash resulting from changes in:
Accounts receivable	(125)	156
Inventory	89	(178)
Prepaid expenses and other assets	(518)	(41)
Accounts payable	(613)	(306)
Accrued expenses	(1,990)	(735)
Deferred rent	(34)	(36)
Deferred revenue	262	(319)
Net cash used in operating activities	(10,653)	(8,541)
Cash Flows From Investing Activities
Purchases of fixed assets	(11)	(12)
Purchases of intangible assets	(70)	0
Net cash used in investing activities	(81)	(12)
Cash Flows From Financing Activities
Proceeds from issuance of common stock and exercise of warrants, net	2,957	0
Net cash provided by financing activities	2,957	0
Net Increase (Decrease) in Cash and Cash Equivalents	(7,777)	(8,553)
Cash and Cash Equivalents at Beginning of Period	62,751	62,091
Cash and Cash Equivalents at End of Period	54,974	53,538
Supplemental Disclosure of Cash Flow Information:
Interest paid	0	0
Income taxes paid	$ 0	$ 22