CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating activities
Net loss	$ (167,392)	$ (219,583)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	4,551	5,394
Amortization and accretion income, net	9	(1,023)
Share-based compensation	45,143	47,425
Amortization of right-of-use assets	2,758	2,213
Gain from lease modification	(1,863)
Undistributed earnings from TRC, LLC	(22,310)	(20,337)
Interest shortfall on 2035 notes, net	5,713	10,144
Loss on extinguishment of debt		15,464
Other	35	(42)
Changes in operating assets and liabilities:
Receivables from collaborative and licensing arrangements	1,867	9,597
Prepaid clinical and development services	7,132	(18,025)
Other prepaid and current assets	(99)	(2,274)
Other assets	(1,006)	578
Accounts payable	2,206	2,133
Accrued personnel-related expenses, accrued clinical and development expenses, and other accrued liabilities	(36,573)	(178)
Accrued interest payable	1,834	132
Deferred revenue	(8,648)	(19,382)
Operating lease liabilities	443	2,021
Other long-term liabilities	776	265
Net cash used in operating activities	(165,424)	(185,478)
Investing activities
Purchases of property and equipment	(2,962)	(5,372)
Purchases of marketable securities	(104,774)	(337,556)
Maturities of marketable securities	221,400	281,318
Proceeds from the sale of marketable securities		19,928
Proceeds from the sale of property and equipment	6	35
Net cash provided by (used in) investing activities	113,670	(41,647)
Financing activities
Proceeds from the sale of ordinary shares, net	108,180	139,915
Proceeds from issuance of 2035 notes, net		380,000
Payment of issuance costs on 2035 notes		(5,326)
Principal payment on notes	(10,730)	(235,347)
Payment of redemption premium on 2033 notes		(11,470)
Proceeds from ESPP purchases	2,862	2,545
Proceeds from option exercises	5	960
Repurchase of shares to satisfy tax withholding	(8,606)	(8,935)
Net cash provided by financing activities	91,711	262,342
Net increase in cash, cash equivalents, and restricted cash	39,957	35,218
Cash, cash equivalents, and restricted cash at beginning of period	82,300	58,897
Cash, cash equivalents, and restricted cash at end of period	122,257	94,115
Supplemental disclosure of cash flow information
Cash paid for interest	25,967	20,287
Cash (received) paid for income taxes, net	$ (3,814)	$ 14