CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net loss	$ (75,760)	$ (108,947)
Adjustments to reconcile net loss to net cash used for operating activities:
Non-cash royalty revenue related to sale of future royalties	(45,159)	(32,102)
Non-cash interest expense on liability related to sale of future royalties and convertible senior notes	17,428	11,525
Depreciation and amortization	1,569	3,277
(Gain) loss on sale/disposal of fixed assets and impairment charges	(691)	2,544
Operating lease right-of-use asset impairment		694
Stock and deferred share unit compensation	10,454	10,939
Change in operating assets and liabilities:
Accounts receivable	2,450	1,607
Unbilled revenue/reimbursement	996	(2,392)
Contract asset	3,631	500
Prepaid and other current assets	(2,450)	(499)
Operating lease right-of-use assets	1,110	994
Other assets	(4,786)	296
Accounts payable	(1,028)	(3,751)
Accrued compensation	(4,651)	2,336
Other accrued liabilities	8,829	(6,058)
Deferred revenue	3,094	65,050
Operating lease liability	(2,191)	(1,823)
Net cash used for operating activities	(87,155)	(55,810)
Cash flows from investing activities:
Purchases of property and equipment	(815)	(2,762)
Proceeds from sale of equipment	1,426
Net cash provided by (used for) investing activities	611	(2,762)
Cash flows from financing activities:
Proceeds from issuance of common stock under stock plans	793	811
Proceeds from common stock issuance, net of $230 of transaction costs	97,743
Net cash provided by financing activities	98,536	811
Net change in cash and cash equivalents	11,992	(57,761)
Cash and cash equivalents, beginning of period	176,225	262,252
Cash and cash equivalents, end of period	$ 188,217	$ 204,491