CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities
Net loss	$ (14,016)	$ (10,870)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	842	646
Depreciation	367	427
Non-cash lease expense	420
Amortization of available-for-sale securities	297	88
Changes in operating assets and liabilities:
Accounts receivable from related party	1,402	(3,000)
Prepaid expenses and other current assets	(2,763)	(2,138)
Accounts payable	(2,801)	(1,131)
Accrued expenses and other current liabilities	(2,171)	(1,180)
Deferred collaboration liability	(3,001)	1,095
Deferred rent and lease incentive		(142)
Operating lease liability	(561)
Other long-term liabilities	(22)	(101)
Net cash used in operating activities	(22,007)	(16,306)
Investing activities
Purchases of available-for-sale securities	(39,250)	(116,156)
Proceeds from maturities and redemptions of available-for-sale securities	35,735	3,778
Purchases of property and equipment	(101)	(65)
Net cash used in investing activities	(3,616)	(112,443)
Financing activities
Proceeds from the issuance of Series D convertible preferred stock		27,400
Proceeds from issuance of common stock upon completion of initial public offering net of commissions and underwriting discounts		128,240
Payment of initial public offering costs		(2,463)
Proceeds from the exercise of stock options		17
Principal payments on finance lease liability	(52)	(46)
Net cash (used in) provided by financing activities	(52)	153,148
Net increase (decrease) in cash, cash equivalents and restricted cash	(25,675)	24,399
Cash, cash equivalents and restricted cash at beginning of period	37,583	29,218
Cash, cash equivalents and restricted cash at end of period	11,908	53,617
Supplemental disclosure of non-cash activities:
Operating lease right-of-use asset recognized upon adoption of ASC 842	$ 11,485
Vesting of early exercised restricted stock		4
Initial public offering costs included in accrued expenses		$ 792