Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash Flows from Operating Activities
Net loss	$ (61,967)	$ (54,840)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	12,740	6,596
Operating lease right-of-use asset amortization	1,168	887
Net amortization of premium on marketable securities	454	821
Depreciation	508	365
Changes in operating assets and liabilities:
Research and development tax incentive receivable		(1,682)
Receivable from collaboration partner - related party	1,523	(4,651)
Prepaid expenses and other assets	(255)	(1,421)
Accounts payable	(184)	4,874
Payable to collaboration partner - related party	(819)	8,664
Accrued expenses and other payables	(1,553)	1,386
Deferred revenue - related party	(1,601)	(12,468)
Operating lease liability	(1,315)	(987)
Net cash used in operating activities	(51,301)	(52,456)
Cash Flows from Investing Activities
Purchase of marketable securities	(102,121)	(163,460)
Proceeds from maturities of marketable securities	132,942	165,080
Purchases of property and equipment	(563)	(640)
Net cash provided by investing activities	30,258	980
Cash Flows from Financing Activities
Proceeds from at-the-market offering, net of issuance costs	14,553	123,995
Proceeds from issuance of common stock upon exercise of stock options and purchases under employee stock purchase plan	3,213	2,563
Tax withholding payments related to net settlement of restricted stock units	(186)	(189)
Issuance costs related to prior period common stock offering	25
Net cash provided by financing activities	17,605	126,369
Effect of exchange rate changes on cash, cash equivalents and restricted cash	10	(74)
Net (decrease) increase in cash, cash equivalents and restricted cash	(3,428)	74,819
Cash, cash equivalents and restricted cash, beginning of period	123,890	117,818
Cash, cash equivalents and restricted cash, end of period	120,462	192,637
Supplemental Disclosure of Non-Cash Financing and Investing Information:
Purchases of property and equipment in accounts payable and accrued liabilities	$ 122	63
Public Offering | Accrued liabilities and other payables
Supplemental Disclosure of Non-Cash Financing and Investing Information:
Issuance costs related to common stock offering		$ 197