Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net loss	$ (19,140)	$ (11,798)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	194	1,616
Warrant revaluation expense (income)	4,742	(10,518)
Derivative revaluation expense (income)	(287)	251
Intangible asset impairment	0	3,905
Depreciation and amortization of long lived assets	282	476
Amortization of debt discount	86	0
Loss on disposal or impairment of property and equipment	40	64
Recovery of doubtful accounts	0	(12)
Decrease (increase) in operating assets:
Accounts receivable	0	12
Inventory	0	482
Prepaid expenses and other current assets	248	1,045
Other assets	4	(64)
Increase (decrease) in operating liabilities:
Accounts payable	132	(212)
Related party payable	789	(10,379)
Accrued expenses and deferred rent	(524)	(53)
Accrued interest payable	555	46
Deferred revenue	0	(457)
Net cash used in operating activities	(12,879)	(25,596)
Cash flows from investing activities:
Purchase of property and equipment	(348)	(187)
Proceeds from the sale of property and equipment	0	1
Net cash used in investing activities	(348)	(186)
Cash flows from financing activities:
Proceeds from 2017 Series A Preferred Stock Offering, (net of offering costs of $377)	7,623	0
Proceeds from private placement offering, net	0	17,933
Payment of deferred offering costs	0	(134)
Principal payments on capital lease obligations	0	(2)
Net cash provided by financing activities	7,623	17,797
Net decrease in cash and cash equivalents	(5,604)	(7,985)
Cash and cash equivalents, beginning of period	17,515	29,268
Cash and cash equivalents, end of period	11,911	21,283
Supplemental disclosures of cash flow information:
Property and equipment in accounts payable	29	33
Offering costs in accounts payable and accrued expenses	0	41
Reduction of warrant liability upon cashless exercise of warrants	41	0
Reduction in accrued interest payable upon cashless exercise of promissory notes	3	0
Reduction in derivative liability upon cashless exercise of promissory notes	6	0
Cashless exercise of promissory notes	85	0
Dividend paid in-kind to preferred stockholders	182	0
Deemed dividend on preferred stock	$ 3,981	$ 0