CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating activities
Net loss	$ (41,359)	$ (49,099)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,109	1,359
Stock-based compensation	7,579	7,008
Non-cash interest expense	892	282
Loss on disposal of property and equipment	5
Deferred income taxes	2	19
Non-cash tax expense from other realized gain on available-for-sale securities		3,825
Gain on sale of investment in marketable equity securities		(3,466)
Changes in operating assets and liabilities:
Accounts receivable	1,939	(3,608)
Inventories	1,043	(1,800)
Other assets	(2,724)	(379)
Accounts payable	3,020	4,022
Accrued liabilities and other non-current liabilities	4,457	(1,477)
Manufacturing and development obligations	(187)	600
Deferred product revenue	73	514
Net cash used in operating activities	(24,151)	(42,200)
Investing activities
Capital expenditures	(624)	(354)
Purchases of investments	(80,453)	(50,183)
Proceeds from maturities and sale of investments	30,002	55,566
Net cash (used in) provided by investing activities	(51,075)	5,029
Financing activities
Net proceeds from equity incentives	7,150	2,421
Net proceeds from public offering	79,301	18,840
Proceeds from loans		30,000
Repayment of debt	(99)	(19,593)
Net cash provided by financing activities	86,352	31,668
Net increase (decrease) in cash, cash equivalents and restricted cash	11,126	(5,503)
Cash, cash equivalents and restricted cash, beginning of period	13,930	22,744
Cash, cash equivalents and restricted cash, end of period	$ 25,056	$ 17,241