CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net loss	$ (43,751)	$ (38,613)
Adjustments to reconcile net loss to net cash used for operating activities:
Non-cash royalty revenue related to sale of future royalties	(8,488)	(7,190)
Non-cash interest expense on liability related to sale of future royalties and convertible senior notes	3,432	3,046
Depreciation and amortization	1,200	2,527
Loss (gain) on sale/disposal of fixed assets and impairment charges	444	(30)
Stock and deferred share unit compensation	5,107	3,847
Deferred rent		15
Change in operating assets and liabilities:
Accounts receivable	1,468	2,615
Unbilled revenue/reimbursement	(3,365)	(258)
Inventory		670
Contract asset	500
Prepaid and other current assets	(2,248)	(2,713)
Operating lease right-of-use assets	348
Other assets	44	(884)
Accounts payable	(2,698)	(757)
Accrued compensation	(7,373)	(5,802)
Other accrued liabilities	931	5,447
Deferred revenue	65,208	(11,875)
Operating lease liability	(556)
Net cash provided (used) for operating activities	10,203	(49,955)
Cash flows from investing activities:
Purchases of property and equipment	(2,127)	(1,028)
Net cash used for investing activities	(2,127)	(1,028)
Cash flows from financing activities:
Proceeds from issuance of common stock under stock plans	68	2,259
Net cash provided by financing activities	68	2,259
Net change in cash and cash equivalents	8,144	(48,724)
Cash and cash equivalents, beginning of period	262,252	267,107
Cash and cash equivalents, end of period	$ 270,396	$ 218,383