Cullinan Therapeutics (CGEM) CSO sells 1,780 shares in Rule 10b5-1 trade

Rhea-AI Filing Summary

Cullinan Therapeutics Chief Scientific Officer Jennifer Michaelson reported an open-market sale of 1,780 shares of common stock at a weighted average price of $14.14 per share. After this transaction, she directly holds 174,844 shares of Cullinan Therapeutics common stock.

The sale was effected under a pre-arranged trading plan established pursuant to Rule 10b5-1 on August 7, 2025. The reported price reflects a weighted average for multiple trades executed between $13.89 and $14.35 per share.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Michaelson Jennifer

(Last) (First) (Middle)

C/O CULLINAN THERAPEUTICS, INC.

ONE MAIN STREET, SUITE 1350

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Cullinan Therapeutics, Inc. [ CGEM ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Scientific Officer

3. Date of Earliest Transaction (Month/Day/Year)
02/25/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	02/25/2026		S(1)		1,780	D	$14.14(2)	174,844	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 on August 7, 2025.

2. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $13.89 to $14.35. The Reporting Person undertakes to provide to the Issuer, any shareholder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

	/s/ Jacquelyn Sumer, Attorney-in-Fact	02/26/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did Cullinan Therapeutics (CGEM) report for Jennifer Michaelson?

Cullinan Therapeutics reported that Chief Scientific Officer Jennifer Michaelson sold 1,780 shares of common stock in an open-market transaction. The weighted average sale price was $14.14 per share, executed across multiple trades within a disclosed price range.

At what prices were the CGEM shares sold by Jennifer Michaelson?

The shares were sold at a weighted average price of $14.14 per share. According to the disclosure, individual trades occurred at prices ranging from $13.89 to $14.35, with the average reported as a single figure for the transaction.

How many Cullinan Therapeutics (CGEM) shares does Jennifer Michaelson hold after the sale?

After the reported sale, Jennifer Michaelson directly holds 174,844 shares of Cullinan Therapeutics common stock. This post-transaction holding reflects her remaining direct ownership as disclosed in the Form 4 insider filing for this transaction.

Was the CGEM insider sale by Jennifer Michaelson under a Rule 10b5-1 plan?

Yes. The transaction was effected pursuant to a pre-arranged trading plan established under Rule 10b5-1 on August 7, 2025. Such plans allow insiders to sell shares according to predetermined instructions, helping separate trading decisions from later nonpublic information.

What role does insider Jennifer Michaelson hold at Cullinan Therapeutics (CGEM)?

Jennifer Michaelson is the Chief Scientific Officer of Cullinan Therapeutics. Her role is disclosed in the insider filing, which identifies her as an officer of the company and provides details of her reported common stock transaction and post-sale share ownership.

How many CGEM shares did Jennifer Michaelson sell in this Form 4 filing?

She sold 1,780 shares of Cullinan Therapeutics common stock in this reported transaction. The filing classifies it as an open-market sale, with a weighted average sale price of $14.14 per share and remaining direct ownership of 174,844 shares afterward.