JACQUELYN L. SUMER - 18 Dec 2025 Form 4 Insider Report for Cullinan Therapeutics, Inc. (CGEM)

Role: Chief Legal Officer
Signature: /s/ Jacquelyn Sumer
Issuer symbol: CGEM
Transactions as of: 18 Dec 2025
Net transactions value: -$33,652
Form type: 4
Filing time: 19 Dec 2025, 17:00:18 UTC
Previous filing: 27 Feb 2025
Next filing: 19 Feb 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
SUMER JACQUELYN L	Chief Legal Officer	C/O CULLINAN THERAPEUTICS, INC., ONE MAIN STREET, SUITE 1350, CAMBRIDGE	/s/ Jacquelyn Sumer	19 Dec 2025	0001844824

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	CGEM	Common Stock	Sale	$33,652	-3,480	-2.5%	$9.67	135,432	18 Dec 2025	Direct	F1, F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Sale of shares to cover personal income tax obligations upon vesting of restricted stock units.
F2	Includes 2,017 shares of common stock that the Reporting Person purchased pursuant to the Issuer's 2021 Employee Stock Purchase Plan for the purchase period of January 1, 2025 through June 30, 2025 that were exempt under both Rule 16b-3(d) and Rule 16b-3(c).