Condensed Consolidated Statements of Changes in Convertible Preferred Stock and Stockholders' Equity/(Deficit) - USD ($) $ in Thousands	Total	Common Stock [Member]	Preferred Stock [Member] Convertible Preferred Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning balance at Dec. 31, 2021	$ (17,249)	$ 0	$ 21,348	$ 143	$ (17,392)	$ 0
Beginning balance, shares at Dec. 31, 2021		875,279	10,329,265
Stock-based compensation expense	65			65
Net loss	(4,881)				(4,881)
Ending balance at Mar. 31, 2022	(22,065)	$ 0	$ 21,348	208	(22,273)	0
Ending balance, shares at Mar. 31, 2022		875,279	10,329,265
Beginning balance at Dec. 31, 2021	(17,249)	$ 0	$ 21,348	143	(17,392)	0
Beginning balance, shares at Dec. 31, 2021		875,279	10,329,265
Net loss	(18,360)
Ending balance at Sep. 30, 2022	(34,754)	$ 0	$ 118,024	1,148	(35,752)	(150)
Ending balance, shares at Sep. 30, 2022		875,279	33,336,282
Beginning balance at Mar. 31, 2022	(22,065)	$ 0	$ 21,348	208	(22,273)	0
Beginning balance, shares at Mar. 31, 2022		875,279	10,329,265
Issuance of convertible preferred stock, net of issuance costs			$ 96,676
Issuance of convertible preferred stock, net of issuance costs, shares			23,007,017
Stock-based compensation expense	279			279
Net loss	(5,695)				(5,695)
Ending balance at Jun. 30, 2022	(27,481)	$ 0	$ 118,024	487	(27,968)
Ending balance, shares at Jun. 30, 2022		875,279	33,336,282
Stock-based compensation expense	661			661
Net loss	(7,784)				(7,784)
Other comprehensive income loss	(150)					(150)
Ending balance at Sep. 30, 2022	(34,754)	$ 0	$ 118,024	1,148	(35,752)	(150)
Ending balance, shares at Sep. 30, 2022		875,279	33,336,282
Beginning balance at Dec. 31, 2022	(44,368)	$ 0	$ 118,024	1,661	(45,868)	(161)
Beginning balance, shares at Dec. 31, 2022		875,279	33,336,282
Stock-based compensation expense	533			533
Net loss	(7,089)				(7,089)
Other comprehensive income loss	104					104
Ending balance at Mar. 31, 2023	(50,820)	$ 0	$ 118,024	2,194	(52,957)	(57)
Ending balance, shares at Mar. 31, 2023		875,279	33,336,282
Beginning balance at Dec. 31, 2022	$ (44,368)	$ 0	$ 118,024	1,661	(45,868)	(161)
Beginning balance, shares at Dec. 31, 2022		875,279	33,336,282
Exercise of common stock options, shares	2,798
Net loss	$ (32,992)
Ending balance at Sep. 30, 2023	178,381	$ 15	$ 0	257,230	(78,860)	(4)
Ending balance, shares at Sep. 30, 2023		14,817,762	0
Beginning balance at Mar. 31, 2023	(50,820)	$ 0	$ 118,024	2,194	(52,957)	(57)
Beginning balance, shares at Mar. 31, 2023		875,279	33,336,282
Stock-based compensation expense	462			462
Net loss	(11,140)				(11,140)
Other comprehensive income loss	38					38
Ending balance at Jun. 30, 2023	(61,460)		$ 118,024	2,656	(64,097)	(19)
Ending balance, shares at Jun. 30, 2023		875,279	33,336,282
Exercise of common stock options	5	$ 1		4
Exercise of common stock options, shares		2,798
Conversion of convertible preferred stock to common stock in connection with the Reverse Merger	118,024	$ 1	$ (118,024)	118,023
Conversion of convertible preferred stock to common stock in connection with the Reverse Merger, shares		7,269,183	(33,336,282)
Issuance of common stock and pre-funded warrants in the pre-closing financing, net of issuance costs	67,750			67,750
Issuance of common stock and pre-funded warrants in the pre-closing financing, net of issuance costs, shares		2,873,988
Issuance of common stock to former stockholders of Magenta Therapeutics, Inc. in connection with the Reverse Merger	71,595			71,595
Issuance of common stock to former stockholders of MagentaTherapeutics, Inc. in connection with the Reverse Merger, shares		3,796,514
Adjustment for change in common stock par value in connection with the Reverse Merger		$ 13		(13)
Reverse recapitalization transaction costs	(3,964)			(3,964)
Stock-based compensation expense	1,179			1,179
Net loss	(14,763)				(14,763)
Other comprehensive income loss	15					15
Ending balance at Sep. 30, 2023	$ 178,381	$ 15	$ 0	$ 257,230	$ (78,860)	$ (4)
Ending balance, shares at Sep. 30, 2023		14,817,762	0