CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating activities
Net loss	$ (18,598)	$ (16,863)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	469	476
Stock-based compensation	2,147	1,776
Non-cash interest expense	195	300
Deferred income taxes	7	9
Non-cash tax expense from other unrealized loss on available-for-sale securities		768
Gain on sale of investment in marketable equity securities	(18)
Changes in operating assets and liabilities:
Accounts receivable	1,285	1,708
Inventories	(388)	(488)
Other assets	(310)	(213)
Accounts payable	198	995
Accrued liabilities	(1,724)	(639)
Manufacturing and development obligations	76	(924)
Deferred product revenue	313	52
Net cash used in operating activities	(16,348)	(13,043)
Investing activities
Capital expenditures	(185)	(43)
Purchases of investments	(10,158)	(50,544)
Proceeds from maturities and sale of investments	16,018	5,500
Net cash provided by (used in) investing activities	5,675	(45,087)
Financing activities
Net proceeds from equity incentives	422	698
Net (payments for) proceeds from public offering	(30)	7,199
Repayment of debt	(1,271)	(32)
Net cash (used in) provided by financing activities	(879)	7,865
Net decrease in cash, cash equivalents and restricted cash	(11,552)	(50,265)
Cash, cash equivalents and restricted cash, beginning of period	22,744	71,630
Cash, cash equivalents and restricted cash, end of period	$ 11,192	$ 21,365