Condensed Consolidated Statements of Cash Flows (Unaudited)	9 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)
Cash flows from operating activities
Net loss	$ (124,137,000)	$ (41,693,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	283,000	3,000
Change in fair value of preferred stock tranche liability		17,030,000
Research and development license expense	6,750,000	6,000,000
Stock-based compensation	13,229,000	1,341,000
Build-to-suit lease	357,000
Other	93,000
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(1,530,000)	(604,000)
Accounts payable	16,000,000	5,403,000
Accrued expenses and other liabilities	12,179,000	1,579,000
Due to related party	(8,000)	60,000
Net cash used in operating activities	(76,784,000)	(10,881,000)
Cash flows from investing activities
Purchase of research and development license	(6,000,000)	(3,000,000)
Purchase of property, plant and equipment	(7,034,000)	(31,000)
Net cash used in investing activities	(13,034,000)	(3,031,000)
Cash flows from financing activities
Proceeds from Term Loan, net	29,978,000
Proceeds from initial public offering, net of underwriting discounts and commission and other offering costs		167,162,000
Proceeds from note payable to related party		1,673,000
Repayment of note payable to related party		(1,673,000)
Net cash provided by financing activities	29,978,000	292,546,000
Net (decrease) increase in cash, cash equivalents and restricted cash	(59,840,000)	278,634,000
Cash, cash equivalents and restricted cash at the beginning of the period	251,253,000
Cash, cash equivalents and restricted cash at the end of the period	191,413,000	278,634,000
Cash and cash equivalents	188,785,000	278,634,000
Restricted cash	2,628,000
Supplemental disclosure of cash flow information:
Cash paid for interest	110,000	28,000
Supplemental disclosure of noncash investing and financing activities:
Property, plant and equipment in accounts payable and accrued expenses	6,658,000
Acquisition of property, plant and equipment funded by landlord	606,000
Build-to-suit lease liability	26,607,000
Deferred offering costs not yet paid	204,000
Reclassification of preferred stock tranche liability		18,080,000
Allocation of preferred stock tranche liability		1,050,000
Conversion of Series A and Series B convertible preferred stock to common stock		142,240,000
Purchase of research and development license not yet paid	$ 750,000	3,000,000
Common Stock
Supplemental disclosure of noncash investing and financing activities:
Issuance costs for issuances of stock not yet paid		1,273,000
Series A Convertible Preferred Stock
Cash flows from financing activities
Proceeds from convertible preferred stock, net of issuance costs		29,569,000
Supplemental disclosure of noncash investing and financing activities:
Issuance costs for issuances of stock not yet paid		174,000
Series B Convertible Preferred Stock
Cash flows from financing activities
Proceeds from convertible preferred stock, net of issuance costs		$ 95,815,000