Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022
Current assets:
Cash and cash equivalents	$ 195,555	$ 154,323	$ 454,620
Marketable securities	473,774	558,528
Receivable from Collaboration partner	4,699	2,587
Prepaid expenses and other current assets	11,974	10,997
Total current assets	686,002	726,435
Property and equipment, net	24,998	25,521
Operating lease right-of-use assets	27,066	27,811
Restricted cash	1,472	1,472	1,472
Other assets	8,804	6,409
Total assets	748,342	787,648
Current liabilities:
Accounts payable	3,126	4,189
Accrued clinical supply costs	7,691	5,559
Accrued liabilities	18,580	27,771
Deferred revenue, current portion	61,773	48,231
Operating lease liabilities, current portion	8,130	8,059
Total current liabilities	99,300	93,809
Deferred revenue, long-term portion	431,079	443,370
Operating lease liabilities, long-term portion	34,050	35,268
Other long-term liabilities	898	759
Total liabilities	565,327	573,206
Commitments and Contingencies
Stockholders' equity:
Common stock, $0.0001 par value; 200,000,000 shares authorized; 83,351,778 and 82,895,718 shares issued and outstanding as of March 31, 2023 and December 31, 2022	8	8
Additional paid-in capital	810,750	798,696
Accumulated other comprehensive loss	(2,199)	(4,575)
Accumulated deficit	(625,544)	(579,687)
Total stockholders' equity	183,015	214,442	$ 267,537
Total liabilities and stockholders’ equity	$ 748,342	$ 787,648