Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net loss	$ (1,407)	$ (8,525)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	545	240
Warrant revaluation (income) expense	(5,257)	1,663
Depreciation and amortization	217	140
Provision for (recovery of) doubtful accounts	(10)	0
Decrease (increase) in operating assets:
Accounts receivable	10	1
Inventory	7	27
Prepaid expenses and other current assets	299	201
Other assets	(30)	0
Increase (decrease) in operating liabilities:
Accounts payable	338	293
Related party payable	(9,642)	936
Accrued expenses and deferred rent	(1,138)	614
Deferred revenue	5	172
Net cash used in operating activities	(16,063)	(4,238)
Cash flows from investing activities:
Purchase of property and equipment	(58)	(108)
Net cash used in investing activities	(58)	(108)
Cash flows from financing activities:
Payment of deferred offering costs	(50)	0
Proceeds from the exercise of stock options	0	152
Principle payments on capital lease obligations	(2)	0
Net cash (used in) provided by financing activities	(52)	152
Net decrease in cash and cash equivalents	(16,173)	(4,194)
Cash and cash equivalents, beginning of period	29,268	37,495
Cash and cash equivalents, end of period	13,095	33,301
Supplemental Cash Flow Disclosures:
Property and equipment in accounts payable	15	0
Deferred offering costs in accounts payable	$ 41	$ 0