Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 168,027	$ 523,506
Marketable securities	686,761	669,116
Accounts receivable ($0 and $0.3 million, respectively, from related party)	6,491	3,768
Prepaid expenses and other current assets	32,214	20,407
Total current assets	893,493	1,216,797
Marketable securities - noncurrent	137,752	69,338
Property and equipment, net	33,800	27,921
Operating lease right-of-use assets	118,775	133,076
Equity method investment	17,166	32,455
Investments and other assets	42,363	40,527
Total Assets	1,243,349	1,520,114
Current Liabilities:
Accounts payable	3,553	5,154
Accrued expenses ($1.0 million and $1.6 million, respectively, from related party)	57,979	60,876
Current portion of operating lease liability	17,074	16,685
Current portion of deferred revenue ($0 and $19.9 million, respectively, from related party)	13,347	43,839
Total current liabilities	91,953	126,554
Deferred revenue, net of current portion	12,719	19,932
Long-term operating lease liability	101,263	114,018
Contingent consideration liability	0	24,026
Total liabilities	205,935	284,530
Commitments and contingencies (Note 6)
Stockholders’ Equity:
Common stock, $0.0001 par value; 240,000,000 and 120,000,000 shares authorized at September 30, 2023 and December 31, 2022, respectively; 89,097,821 and 87,103,007 shares issued and outstanding at September 30, 2023 and December 31, 2022, respectively	9	9
Additional paid-in capital	2,567,195	2,420,223
Accumulated other comprehensive loss	(3,572)	(7,461)
Accumulated deficit	(1,526,218)	(1,177,187)
Total stockholders’ equity	1,037,414	1,235,584
Total Liabilities and Stockholders’ Equity	$ 1,243,349	$ 1,520,114