CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net loss	$ (29,088)	$ (43,751)
Adjustments to reconcile net loss to net cash (used for) provided by operating activities:
Non-cash royalty revenue related to sale of future royalties	(12,997)	(8,488)
Non-cash interest expense on liability related to sale of future royalties and convertible senior notes	5,702	3,432
Depreciation and amortization	529	1,200
(Gain) loss on sale/disposal of fixed assets and impairment charges	(709)	444
Stock and deferred share unit compensation	3,122	5,107
Change in operating assets and liabilities:
Accounts receivable	7,446	1,468
Unbilled revenue/reimbursement	(752)	(3,365)
Contract asset	2,641	500
Prepaid and other current assets	(2,228)	(2,248)
Operating lease right-of-use assets	353	348
Other assets	(3,047)	44
Accounts payable	(649)	(2,698)
Accrued compensation	(3,267)	(7,373)
Other accrued liabilities	5,253	931
Deferred revenue	78	65,208
Operating lease liability	(702)	(556)
Net cash (used for) provided by operating activities	(28,315)	10,203
Cash flows from investing activities:
Purchases of property and equipment	(21)	(2,127)
Proceeds from sale of equipment	1,426
Net cash provided by (used for) investing activities	1,405	(2,127)
Cash flows from financing activities:
Proceeds from issuance of common stock under stock plans	240	68
Proceeds from common stock issuance, net of $229 of transaction costs	97,744
Net cash provided by financing activities	97,984	68
Net change in cash and cash equivalents	71,074	8,144
Cash and cash equivalents, beginning of period	176,225	262,252
Cash and cash equivalents, end of period	$ 247,299	$ 270,396