Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 72,552	$ 74,555
Marketable securities	489,531	474,306
Prepaid expenses and other current assets	19,307	16,946
Total current assets	581,390	565,807
Property and equipment, net	20,835	21,861
Operating lease right-of-use assets	24,321	25,195
Restricted cash	1,546	1,546
Other assets	7,402	7,418
Total assets	635,494	621,827
Current liabilities:
Accounts payable	4,586	3,775
Accrued clinical supply costs	5,870	5,215
Accrued liabilities	19,385	30,378
Deferred revenue, current portion	73,352	82,975
Payable to collaboration partner	15,632	7,703
Refund liability to collaboration partner, current portion	37,557	39,440
Operating lease liabilities, current portion	8,535	8,462
Total current liabilities	164,917	177,948
Deferred revenue, long-term portion	204,575	210,845
Refund liability to collaboration partner, long-term portion	56,700	67,047
Operating lease liabilities, long-term portion	29,022	30,456
Other long-term liabilities	1,373	1,373
Total liabilities	456,587	487,669
Commitments and contingencies (Note 4)
Stockholders' equity:
Common stock, $0.0001 par value; 200,000,000 shares authorized; 96,384,562 and 84,879,693 shares issued and outstanding as of March 31, 2024 and December 31, 2023	9	8
Additional paid-in capital	925,458	844,044
Accumulated other comprehensive income (loss)	(403)	184
Accumulated deficit	(746,157)	(710,078)
Total stockholders' equity	178,907	134,158
Total liabilities and stockholders’ equity	$ 635,494	$ 621,827