Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net loss	$ (26,339)	$ (24,013)	$ (18,881)
Adjustments to reconcile net loss to net cash used for operating activities:
Depreciation	292	270	254
Amortization of deferred loan costs	238	198	226
Amortization of debt discount	3,739	1,635	633
Interest expense added to loan principal	7,636	8,237	7,659
Interest added to lease liability	755
Loss on debt conversion	1,234
Loss on early extinguishment of debt and debt refinancing	2,250
Compensation charge for stock awards and share options	1,296	1,116	1,077
Changes in operating assets and liabilities:
Decrease in accounts receivable	148	52	52
(Increase) decrease in prepaid expenses and other	(3,082)	37	4
Increase in other assets	(185)	(186)	(186)
Increase (decrease) in accounts payable	130	9	(533)
Increase (decrease) in accrued liabilities	2,374	77	(426)
Net cash used for operating activities	(9,514)	(12,568)	(10,121)
Cash flows from investing activities:
Additions to property, plant and equipment		(906)	(72)
Net cash used for investing activities		(906)	(72)
Cash flows from financing activities:
Net proceeds from issuance of common stock	10,510		14,523
Up-front payment related to lease liability	12,000
Net proceeds from issuance of long-term debt	8,000
Debt issuance costs	(960)
Principal payments on long-term debt	(10,554)	(42)	(11)
Net cash provided by (used for) financing activities	18,996	(42)	14,512
Net increase (decrease) in cash and cash equivalents	9,482	(13,516)	4,319
Cash and cash equivalents, beginning of period	2,690	16,206	11,887
Cash and cash equivalents, end of period	$ 12,172	$ 2,690	$ 16,206