Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net loss	$ (5,007)	$ (1,407)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation (income) expense	(49)	545
Warrant revaluation expense (income)	46	(5,257)
Derivative revaluation expense	312	0
Depreciation and amortization	91	217
Loss on disposal or impairment of property and equipment	30	0
Recovery of doubtful accounts	0	(10)
Decrease (increase) in operating assets:
Accounts receivable	0	10
Inventory	0	7
Prepaid expenses and other current assets	(51)	299
Other assets	(34)	(30)
Increase (decrease) in operating liabilities:
Accounts payable	(55)	338
Related party payable	567	(9,642)
Accrued expenses and deferred rent	(787)	(1,138)
Accrued interest payable	183	0
Deferred revenue	0	5
Net cash used in operating activities	(4,754)	(16,063)
Cash flows from investing activities:
Purchase of property and equipment	(87)	(58)
Net cash used in investing activities	(87)	(58)
Cash flows from financing activities:
Proceeds from 2017 Series A Preferred Stock Offering, net	7,886	0
Payment of deferred offering costs	0	(50)
Principal payments on capital lease obligations	0	(2)
Net cash provided by (used in) financing activities	7,886	(52)
Net increase (decrease) in cash and cash equivalents	3,045	(16,173)
Cash and cash equivalents, beginning of period	17,515	29,268
Cash and cash equivalents, end of period	20,560	13,095
Supplemental disclosures of cash flow information:
Property and equipment in accounts payable	13	15
Offering costs in accounts payable and accrued expenses	263	41
Reduction of warrant liability upon cashless exercise of warrants	41	0
Dividend paid in-kind to preferred stockholders	20	0
Deemed dividend on preferred stock	$ 3,734	$ 0