Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 120,237	$ 123,665
Marketable securities	171,653	203,235
Restricted cash - current	225
Receivable from collaboration partner and contract asset - related party	43	1,566
Research and development tax incentive receivable	2,648	2,792
Prepaid expenses and other current assets	9,721	9,478
Total current assets	304,302	340,736
Property and equipment, net	1,962	1,798
Restricted cash - noncurrent	225	225
Operating lease right-of-use asset	4,023	4,936
Total assets	310,512	347,695
Current liabilities:
Accounts payable	1,412	1,600
Payable to collaboration partner - related party	80	899
Accrued expenses and other payables	36,244	37,716
Deferred revenue - related party		1,601
Operating lease liability - current	2,352	2,200
Total current liabilities	40,088	44,016
Operating lease liability - noncurrent	2,446	3,658
Total liabilities	42,534	47,674
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.00001 par value, 10,000,000 shares authorized; no shares issued and outstanding
Common stock, $0.00001 par value, 90,000,000 shares authorized; 48,683,931 and 47,838,330 shares issued and outstanding as of June 30, 2022 and December 31, 2021, respectively
Additional paid-in capital	740,027	709,682
Accumulated other comprehensive loss	(720)	(299)
Accumulated deficit	(471,329)	(409,362)
Total stockholders' equity	267,978	300,021
Total liabilities and stockholders' equity	$ 310,512	$ 347,695