CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net loss	$ (53,386)	$ (87,197)
Adjustments to reconcile net loss to net cash (used for) provided by operating activities:
Non-cash royalty revenue related to sale of future royalties	(27,072)	(18,900)
Non-cash interest expense on liability related to sale of future royalties and convertible senior notes	11,783	7,250
Depreciation and amortization	1,045	2,438
(Gain) loss on sale/disposal of fixed assets and impairment charges	(691)	2,404
Operating lease right-of-use asset impairment		559
Stock and deferred share unit compensation	6,576	7,313
Change in operating assets and liabilities:
Accounts receivable	7,187	1,701
Unbilled revenue/reimbursement	996	(1,857)
Contract asset	2,589	500
Prepaid and other current assets	(1,001)	(2,187)
Operating lease right-of-use assets	723	664
Other assets	(3,807)	1,859
Accounts payable	2,161	(3,199)
Accrued compensation	(4,191)	9,238
Other accrued liabilities	2,832	(5,346)
Deferred revenue	(817)	65,129
Operating lease liability	(1,435)	(1,179)
Net cash used for operating activities	(56,508)	(20,810)
Cash flows from investing activities:
Purchases of property and equipment	(44)	(2,355)
Proceeds from sale of equipment	1,426
Net cash provided by (used for) investing activities	1,382	(2,355)
Cash flows from financing activities:
Proceeds from issuance of common stock under stock plans	664	738
Proceeds from common stock issuance, net of $230 of transaction costs	97,743
Net cash provided by financing activities	98,407	738
Net change in cash and cash equivalents	43,281	(22,427)
Cash and cash equivalents, beginning of period	176,225	262,252
Cash and cash equivalents, end of period	$ 219,506	$ 239,825