CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating activities
Net loss	$ (49,405)	$ (41,112)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,394	1,229
Stock-based compensation	5,966	4,912
Changes in valuation of warrant liability		(4,698)
Non-cash interest expense	820	230
Deferred income taxes	18	12
Non-cash tax expense (benefit) from other unrealized loss on available-for-sale securities	1,246	(2,034)
Changes in operating assets and liabilities:
Accounts receivable	(1,647)	(153)
Inventories	(1,432)	1,970
Other assets	354	802
Accounts payable	1,562	(3,085)
Accrued liabilities	258	(375)
Manufacturing and development obligations	(3,258)
Deferred product revenue	306	(42)
Net cash used in operating activities	(43,818)	(42,344)
Investing activities
Capital expenditures	(359)	(561)
Purchases of investments	(71,760)	(78,261)
Proceeds from maturities of investments	33,500	57,444
Restricted cash	34	(115)
Net cash used in investing activities	(38,585)	(21,493)
Financing activities
Net proceeds from equity incentives and warrants	2,710	6,609
Net proceeds from public offering	22,146	75,327
Proceeds from loans		10,000
Repayment of debt	(591)	(85)
Net cash provided by financing activities	24,265	91,851
Net (decrease) increase in cash and cash equivalents	(58,138)	28,014
Cash and cash equivalents, beginning of period	71,018	22,781
Cash and cash equivalents, end of period	$ 12,880	$ 50,795