Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities:
Net loss	$ (107,555,000)	$ (92,300,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,708,000	509,000
Stock-based compensation expense	14,729,000	5,448,000
In-process research and development expenses	2,000,000	10,848,000
Issuance of common stock to Erasca Foundation		17,497,000
(Accretion) amortization on marketable securities, net	(169,000)	75,000
Change in fair value of preferred stock purchase right liability		(1,615,000)
Changes in operating assets and liabilities:
Prepaid expenses and other current and long-term assets	(4,512,000)	(5,592,000)
Accounts payable	1,540,000	409,000
Accrued expenses and other current liabilities	2,936,000	7,173,000
Operating lease assets and liabilities, net	12,431,000	430,000
Net cash used in operating activities	(76,892,000)	(57,118,000)
Cash flows from investing activities:
Purchases of marketable securities	(94,427,000)	(41,696,000)
Maturities of marketable securities	45,900,000	54,110,000
In-process research and development	(2,000,000)	(7,680,000)
Payment made for investment in equity securities	(2,000,000)
Purchases of property and equipment	(13,687,000)	(5,375,000)
Net cash used in investing activities	(66,214,000)	(641,000)
Cash flows from financing activities:
Proceeds from the issuance of common stock in initial public offering, net of discounts and issuance costs		316,999,000
Proceeds from the issuance of convertible preferred stock, net of issuance costs		119,393,000
Proceeds from the exercise of stock options, net of repurchases	1,262,000	1,345,000
Proceeds from issuance of common stock under the Employee Stock Purchase Plan	617,000
Proceeds from the disgorgement of stockholder's short-swing profits		553,000
Net cash provided by financing activities	1,879,000	438,290,000
Net (decrease) increase in cash, cash equivalents and restricted cash	(141,227,000)	380,531,000
Cash, cash equivalents and restricted cash at beginning of the period	360,895,000	65,688,000
Cash, cash equivalents and restricted cash at end of the period	219,668,000	446,219,000
Supplemental disclosure of noncash investing and financing activities:
Issuance of common stock to Erasca Foundation		17,497,000
Issuance of common stock in connection with asset acquisition		1,680,000
Issuance of common stock in connection with license agreement		5,488,000
Amounts accrued for purchases of property and equipment	841,000	1,882,000
Conversion of preferred stock to common stock upon initial public offering		340,798,000
Vesting of early exercised options	955,000	519,000
Operating lease assets obtained in exchange for lease obligation	22,704,000	17,498,000
Reduction in operating lease assets due to lease amendment	$ 3,361,000
Tenant improvement allowance included in operating lease liabilities		$ 16,774,000