Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities
Net loss	$ (76,723)	$ (50,139)
Adjustments to reconcile net loss to net cash used in operating activities
Stock-based compensation expense	10,800	9,920
Depreciation and amortization	2,591	1,929
Provision for credit losses	0	565
Net amortization of premiums on marketable debt securities	1,460	1,288
Net gains on investments		(7)
Imputed interest income from licensing	(94)	(29)
Non-cash interest expense	54	3,786
Other non-cash adjustments	(43)	(154)
Changes in operating assets and liabilities
Accounts receivable	5,689	1,618
Prepaid expenses	210	(3,334)
Other current assets	3,042	(873)
Operating lease right-of-use assets	979	1,232
Other assets	(2,101)	(3,789)
Accounts payable	16,755	278
Accrued expenses and other current liabilities	(26,473)	(10,544)
Operating lease liabilities	1,008	4,244
Other liabilities	6,935	(38)
Net cash used in operating activities	(55,911)	(44,047)
Cash flows from investing activities
Purchases of marketable debt securities	(129,486)	(233,627)
Maturities of marketable debt securities	49,862	50,465
Purchases of property and equipment	(10,967)	(31,021)
Net cash used in investing activities	(90,591)	(214,183)
Cash flows from financing activities
Proceeds from exercise of stock options	337	1,292
Taxes paid related to net settlement of stock-based awards	(284)
Proceeds from issuance of common stock under employee stock purchase plan	622	627
Proceeds from public offering of common stock, net of underwriting discounts and commissions		216,438
Issuance costs for public offering of common stock		(251)
Repayments under liability related to sale of future royalties, net of imputed interest	(7,509)	(6,555)
Transaction costs for sale of future royalties		(265)
Net cash provided by (used in) financing activities	(6,834)	211,286
Net decrease in cash and cash equivalents and restricted cash	(153,336)	(46,944)
Cash and cash equivalents and restricted cash
Beginning of period	347,239	339,756
End of period	$ 193,903	$ 292,812