Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss	$ (184,062)	$ (182,814)	$ (108,897)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	777	748	724
Stock-based compensation expense	34,640	14,794	17,719
Non-cash interest expense on royalty financing obligations and secured term loan and amortization of debt issuance costs	54,204	3,325	1,278
Amortization of premium/discount on investments	(2)	121	117
Change in fair value of foreign currency derivative		632	347
(Gain) loss on extinguishment of debt	(55,838)	2,011
(Gain) loss on extinguishment of debt		1,211
Changes in operating assets and liabilities:
Receivables	(20,817)	13,903	(17,853)
Inventory	(8,767)	(7,039)	1,649
Prepaid expenses and other assets	(7,155)	(2,140)	(1,364)
Accounts payable and accrued expenses	39,412	17,355	11,741
Interest payable	4,168	6,766	3,056
Deferred revenue	1,283	(1,970)	1,899
Net cash used in operating activities	(142,157)	(135,108)	(89,584)
Cash flows from investing activities:
Acquisition of property and equipment	(2,385)	(514)	(343)
Purchases of investments	(10,012)	(49,818)	(3,018)
Sales and maturities of investments	28,201	43,476	81,295
Net cash provided by (used in) investing activities	15,804	(6,856)	77,934
Cash flows from financing activities:
Sale of common stock, net	50,000	93,279	58,500
Sale of pre-funded warrants		14,817	19,882
Net proceeds from common stock issued under stock-based compensation plans	15,794	2,446	1,239
Proceeds from senior credit facility			19,477
Payment of senior credit facility		(52,420)
Net proceeds from secured term loan		119,867
Net proceeds from royalty financing obligations	293,874	122,600
Net cash provided by financing activities	359,668	300,589	99,098
Effects of exchange rates on cash, cash equivalents and restricted cash	71
Increase in cash, cash equivalents and restricted cash	233,386	158,625	87,448
Cash, cash equivalents and restricted cash at beginning of year	274,348	115,723	28,275
Cash, cash equivalents and restricted cash at end of year	$ 507,734	$ 274,348	$ 115,723