Net Loss per Share Attributable to Cullinan (Tables)

12 Months Ended

Dec. 31, 2025

Earnings Per Share [Abstract]

Summary of Calculation of Basic and Diluted Net Loss Per Share

The following table sets forth the calculation of basic and diluted net loss per share attributable to Cullinan for 2025 and 2024 (in thousands, except per share data):

	2025						2024
	Common Stock			Preferred Stock			Common Stock			Preferred Stock
Numerator:
Net loss attributable to Cullinan - basic and diluted	$	(198,212	)	$	(21,667	)	$	(149,393	)	$	(17,990	)
Denominator:
Weighted-average shares outstanding - basic and diluted		59,050			645			53,771			648
Net loss per share attributable to Cullinan:
Basic and diluted	$	(3.36	)	$	(33.57	)	$	(2.78	)	$	(27.78	)

Summary of Outstanding Equity Instruments Excluded from Computation of Diluted Net Income (Loss) Per Share

The following table sets forth potential common shares that were excluded from the computation of diluted net loss per share attributable to common stockholders of Cullinan for 2025 and 2024 because their effect would have been anti-dilutive (in thousands):

	2025		2024
Stock options		12,958		8,989
Preferred stock		6,455		6,475
RSUs		1,644		292
ESPP		4		6
Total		21,061		15,762