Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 294,150	$ 523,506
Marketable securities	639,392	669,116
Accounts receivable ($0.3 million each period from related party)	4,906	3,768
Prepaid expenses and other current assets	25,223	20,407
Total current assets	963,671	1,216,797
Marketable securities - noncurrent	225,038	69,338
Property and equipment, net	31,606	27,921
Operating lease right-of-use assets	128,265	133,076
Equity method investment	28,389	32,455
Investments and other assets	40,920	40,527
Total Assets	1,417,889	1,520,114
Current Liabilities:
Accounts payable	6,890	5,154
Accrued expenses ($0.7 million and $1.6 million from related party)	44,822	60,876
Current portion of operating lease liability	16,328	16,685
Current portion of deferred revenue ($11.4 million and $19.9 million from related party)	35,343	43,839
Total current liabilities	103,383	126,554
Deferred revenue, net of current portion	13,862	19,932
Long-term operating lease liability	109,801	114,018
Contingent consideration liability	0	24,026
Commitments and contingencies (Note 6)
Stockholders’ Equity:
Common stock, $0.0001 par value; 120,000,000 shares authorized; 88,095,779 and 87,103,007 shares issued and outstanding at March 31, 2023 and December 31, 2022, respectively	9	9
Additional paid-in capital	2,473,825	2,420,223
Accumulated other comprehensive loss	(2,678)	(7,461)
Accumulated deficit	(1,280,313)	(1,177,187)
Total stockholders’ equity	1,190,843	1,235,584
Total Liabilities and Stockholders’ Equity	$ 1,417,889	$ 1,520,114