CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities
Net loss	$ (86,450)	$ (88,502)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	171	552
Non-cash lease expense	233	720
(Accretion) amortization of short-term investment (discounts) premiums	(1,253)	49
Stock-based compensation expense	20,317	21,418
Changes in operating assets and liabilities:
Interest receivable	51	(41)
Prepaid expenses and other current assets and prepaid expenses to related party	2,856	1,423
Other assets	(72)	245
Income tax payable	(1)	(853)
Accounts payable, accrued expenses and amount due to related party	4,908	(10,365)
Net cash used in operating activities	(59,240)	(75,354)
Cash flows from investing activities
Purchase of short-term investments	(14,196)	(92,783)
Maturities of short-term investments	93,814	37,325
Net cash provided by (used in) investing activities	79,618	(55,458)
Cash flows from financing activities
Proceeds from issuance of common stock in public offering, net of underwriting discounts, commissions and offering costs	70,169
Proceeds from issuance of stock under the 2020 Employee Stock Purchase Plan	315	244
Net cash provided by financing activities	70,484	244
Net increase (decrease) in cash, cash equivalents, and restricted cash	90,862	(130,568)
Cash, cash equivalents, and restricted cash at beginning of period	106,944	202,513
Cash, cash equivalents, and restricted cash at end of period	197,806	71,945
Non-cash investing and financing activities
Unrealized gain (loss) on available-for-sale securities	243	(289)
Deferred offering costs included in accounts payable and accrued expenses	331
Reduction of right-of-use asset and operating lease liability due to modification and remeasurement		(5,506)
Supplemental disclosure of cash flows
Income taxes paid, net of refunds	350	1,003
Cash and cash equivalents	196,954	71,093
Restricted cash	852	852
Total cash, cash equivalents, and restricted cash	$ 197,806	$ 71,945