Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($)		Jun. 30, 2024	Dec. 31, 2023
Convertible preferred stock, shares authorized			189,613,384
Convertible preferred stock, shares issued			151,456,144
Convertible preferred stock, shares outstanding			151,456,144
Convertible preferred stock, liquidation preference			$ 186,182,000
Undesignated preferred stock, par value		$ 0.001	$ 0.001
Undesignated preferred stock, shares authorized		10,000,000	0
Undesignated preferred stock, shares issued		0	0
Undesignated preferred stock, shares outstanding		0	0
Common stock, par value		$ 0.001	$ 0.001
Common stock, shares authorized		500,000,000	250,000,000
Common stock, shares issued		36,576,457	4,170,817
Common stock, shares outstanding		36,576,457	4,170,817
Accounts payable	[1]	$ 1,875,000	$ 2,502,000
Accrued expenses	[1]	5,517,000	5,631,000
Third Rock Ventures LLC
Accounts payable		0	200,000
Third Rock Ventures LLC | Maximum
Accrued expenses		$ 100,000	$ 0
Series A Convertible Preferred Stock
Convertible preferred stock, par value		$ 0.001	$ 0.001
Convertible preferred stock, shares authorized		0	100,182,354
Convertible preferred stock, shares issued		0	100,182,354
Convertible preferred stock, shares outstanding		0	100,182,354
Convertible preferred stock, liquidation preference		$ 0	$ 100,182,000
Series B Convertible Preferred Stock
Convertible preferred stock, par value		$ 0.001	$ 0.001
Convertible preferred stock, shares authorized		0	89,431,030
Convertible preferred stock, shares issued		0	51,273,790
Convertible preferred stock, shares outstanding		0	51,273,790
Convertible preferred stock, liquidation preference		$ 0	$ 86,000,000

[1] Includes related party amounts of zero and $0.2 million (accounts payable) and less than $0.1 million and zero (accrued expenses) as of June 30, 2024 and December 31, 2023, respectively (see Notes 5 and 10).