Consolidated Statements of Cash Flows - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2020
Cash flows from operating activities
Net loss	$ (1,115,000)	$ (60,011,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	0	9,000
Change in fair value of preferred stock tranche liability	0	17,030,000
Research and development license expense	980,000	9,000,000
Stock-based compensation	0	3,354,000
Changes in operating assets and liabilities:
Prepaid expenses and other assets	0	(6,585,000)
Accounts payable	0	1,961,000
Accrued expenses and other liabilities	135,000	4,513,000
Net cash used in operating activities	0	(30,729,000)
Cash flows from investing activities
Purchase of research and development licenses	0	(9,000,000)
Purchase of property and equipment	0	(82,000)
Net cash used in investing activities	0	(9,082,000)
Cash flows from financing activities
Proceeds from issuance of common stock in initial public offering, net of underwriting discounts and commission and other offering costs	0	165,854,000
Proceeds from notes payable to related party	0	1,673,000
Repayment of notes payable to related party	0	(1,673,000)
Net cash provided by financing activities	0	291,064,000
Net increase in cash and cash equivalents	0	251,253,000
Cash at the beginning of the period	0	0
Cash at the end of the period	0	251,253,000
Supplemental disclosure of cash flow information:
Cash paid for interest	0	28,000
Supplemental disclosure of noncash investing and financing activities:
Property and equipment in accounts payable and accrued expenses	0	214,000
Reclassification of preferred stock tranche liability upon share issuance	0	18,080,000
Allocation of preferred stock tranche liability	0	1,050,000
Conversion of Series A and Series B convertible preferred stock to common stock	0	142,240,000
Deferred offering costs not yet paid	15,000
Series A Convertible Preferred Stock
Cash flows from financing activities
Proceeds from issuances of convertible preferred stock, net of issuance costs	0	29,395,000
Series B Convertible Preferred Stock
Cash flows from financing activities
Proceeds from issuances of convertible preferred stock, net of issuance costs	$ 0	$ 95,815,000