Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net loss	$ (34,453)	$ (25,650)	$ (31,554)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock issued to related party for exclusive channel collaboration agreement	0	5,154	6,406
Stock-based compensation expense	2,038	1,239	1,150
Warrant revaluation and other finance (income) expense	(2,929)	(3,930)	1,053
Deferred tax benefit	0	0	0
Loss on disposal of property and equipment	56	13	5
Depreciation and amortization	767	883	863
(Recovery of) provision for doubtful accounts	(5)	12	(20)
Change in operating assets and liabilities:
Accounts receivable	9	12	54
Inventory	89	26	(120)
Prepaid expenses and other current assets	35	(76)	69
Other assets	0	214	(215)
Accounts payable	(114)	(1,065)	807
Related party payable	9,719	(290)	1,230
Accrued expenses and deferred rent	641	894	188
Deferred revenue	41	268	9
Net cash used in operating activities	(24,106)	(22,296)	(20,075)
Cash flows from investing activities:
Purchase of property and equipment	(271)	(242)	(360)
Proceeds from the sale of property and equipment	26	0	0
Net cash used in investing activities	(245)	(242)	(360)
Cash flows from financing activities:
Proceeds from equity financing, net	15,872	0	47,118
Proceeds from the exercise of stock options	255	0	0
Subscription received	0	0	2,004
Principle payments on capital lease obligations	(3)	0	0
Net cash provided by financing activities	16,124	0	49,122
Net (decrease) increase in cash and cash equivalents	(8,227)	(22,538)	28,687
Cash and cash equivalents, beginning of period	37,495	60,033	31,346
Cash and cash equivalents, end of period	29,268	37,495	60,033
Noncash Investing and Financing Items [Abstract]
Property and equipment in accounts payable	11	0	0
Reduction of warrant liability upon cashless exercise of warrants	$ 82	$ 0	$ 352