CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating activities
Net loss	$ (18,792)	$ (13,885)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	729	413
Stock-based compensation	2,878	2,315
Non-cash interest expense	197	269
Changes in operating assets and liabilities:
Accounts receivable	(5,004)	1,926
Inventories	(2,286)	1,224
Other assets	2,165	(1,475)
Accounts payable	2,597	(122)
Accrued liabilities and other non-current liabilities	(4,809)	(1,340)
Manufacturing and development obligations	(118)	164
Deferred product revenue	265	186
Net cash used in operating activities	(22,178)	(10,325)
Investing activities
Capital expenditures	(3,315)	(52)
Purchases of investments	(1,000)	(56,941)
Proceeds from maturities and sale of investments	17,500	12,250
Net cash provided by (used in) investing activities	13,185	(44,743)
Financing activities
Net proceeds from equity incentives	710	1,295
Net proceeds from public offering		57,564
Proceeds from loans, net of discount	39,433
Repayment of debt	(31,010)	(32)
Net cash provided by financing activities	9,133	58,827
Net increase in cash, cash equivalents and restricted cash	140	3,759
Cash, cash equivalents and restricted cash, beginning of period	31,587	13,930
Cash, cash equivalents and restricted cash, end of period	$ 31,727	$ 17,689