Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating activities
Net loss	$ (68,920)	$ (1,420)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	15,783	9,953
Depreciation of property and equipment	1,120	275
Non-cash lease expense	1,165	695
Non-cash interest expense, net	1,771	424
Changes in assets and liabilities:
Accounts receivable, other	19	20
Accounts receivable due from related party	(21)	(72)
Prepaids and other current assets	994	(388)
Other assets	19	254
Accounts payable	2,636	370
Operating lease liabilities	8,094	(323)
Other liabilities	(214)	(486)
Deferred revenue from related party	(1,864)	(55,066)
Net cash used in operating activities	(39,418)	(45,764)
Investing activities
Purchases of property and equipment, net	(14,177)	(2,130)
Purchases of investments	(198,944)	(100,708)
Maturities of investments	299,555	91,830
Net cash provided by (used in) investing activities	86,434	(11,008)
Financing activities
Proceeds from issuance of common stock	0	325,654
Proceeds from exercise of stock options and employee stock purchase plan	3,165	24,495
Employees' tax withheld and paid for with restricted stock units	(5,273)	(3,709)
Borrowings under credit facility agreement, net of issuance costs	0	4,358
Net cash provided by (used in) financing activities	(2,108)	350,798
Net increase in cash, cash equivalents and restricted cash	44,908	294,026
Cash, cash equivalents and restricted cash at beginning of period	33,377	40,259
Cash, cash equivalents and restricted cash at end of period	78,285	334,285
Supplemental disclosures of cash flow information
Cash paid for interest	1,029	913
Right-of-use assets obtained in exchange for lease obligations	455	27,078
Purchases of property and equipment, net recorded in accounts payable and accrued liabilities	$ 4,436	$ 1,560