Cullinan Therapeutics officer sells 4,000 shares

The sale was made under a Rule 10b5-1 plan established on August 7, 2025, alongside an option exercise for common shares.

Available on EDGAR 11/06/2026 - 05:00 PM EST Accepted by SEC EDGAR 11/06/2026 - 05:00 PM EST Learn about SEC filing dates

Rhea-AI Filing Summary

At Cullinan Therapeutics, Inc., Chief Scientific Officer Jennifer Michaelson exercised options for 3,805 shares of common stock on November 5, 2026, at an exercise price of $4.30 per share. On the same date, she sold 4,000 shares at $12.36 per share pursuant to a Rule 10b5-1 plan established on August 7, 2025. After the exercise, reported stock option holdings were 75,182 shares.

Insider Trade Summary 10b5-1

Exercise and sale activity reported; no spread calculated

Exercise and Sale 3 txns

Insider Michaelson Jennifer

Role Chief Scientific Officer

Sold 4,000 shs ($49K)

Approx. gross sale proceeds $49K

Approx. exercise cost $16K

Share of Position Sold 2.5%

Type	Security	Shares	Price	Value
Exercise	Stock Option (Right to Buy) F2	3,805	$0.00	$0.00
Exercise	Common Stock	3,805	$4.30	$16K
Sale	Common Stock F1	4,000	$12.36	$49K

Holdings After Transaction: Stock Option (Right to Buy) — 75,182 contracts (Direct); Common Stock — 158,649 shares (Direct)

Holdings Before and After: Stock Option (Right to Buy), 78,987 to 75,182 contracts (Direct); Common Stock, 158,844 to 158,649 shares (Direct)

Footnotes (2)

1. F1. Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 on August 7, 2025.
2. F2. 25% of the shares vested on July 4, 2020, and the remaining shares vested in 36 equal monthly installments thereafter.

Key Figures

Options exercised: 3,805 shares Exercise price: $4.30 per share Shares sold: 4,000 shares +2 more

5 metrics

Options exercised 3,805 shares November 5, 2026

Exercise price $4.30 per share Option exercise on November 5, 2026

Shares sold 4,000 shares November 5, 2026

Sale price $12.36 per share Sale on November 5, 2026

Stock options following exercise 75,182 shares Reported after the November 5, 2026 exercise

Key Terms

Rule 10b5-1, Stock Option (Right to Buy), vested

3 terms

Rule 10b5-1 regulatory

"pursuant to a plan established pursuant to Rule 10b5-1"

Rule 10b5-1 is a regulation that allows company insiders to buy or sell their shares at predetermined times, even if they have access to non-public information. It acts like setting a schedule in advance for transactions, helping prevent accusations of unfair trading. This rule provides a way for insiders to plan trades transparently, giving investors confidence that these transactions are not based on hidden information.

Stock Option (Right to Buy) financial

"Stock Option (Right to Buy)"

vested financial

"25% of the shares vested on July 4, 2020"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

How many CGEM shares did Jennifer Michaelson sell?

Jennifer Michaelson sold 4,000 shares of common stock at $12.36 per share on November 5, 2026. The sale was made pursuant to a Rule 10b5-1 plan established on August 7, 2025.

How many CGEM shares did Jennifer Michaelson acquire through option exercise?

She exercised options for 3,805 common shares at an exercise price of $4.30 per share on November 5, 2026. Reported stock option holdings after the exercise were 75,182 shares.

When did Jennifer Michaelson's CGEM options vest?

The option footnote states that 25% of the shares vested on July 4, 2020, with the remaining shares vesting in 36 equal monthly installments thereafter.

AI-generated analysis. How Rhea-AI works. Not financial advice.

Form 4 Insider Transactions: What Each Field Means →

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

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 MASSACHUSETTS 02142

(City) (State) (Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
11/05/2026

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

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

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

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	11/05/2026		M		3,805	A	$4.3	162,649	D
Common Stock	11/05/2026		S(1)		4,000	D	$12.36	158,649	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
Stock Option (Right to Buy)	$4.3	11/05/2026		M			3,805	(2)	10/28/2030	Common Stock	3,805	$0	75,182	D

Explanation of Responses:

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

2. 25% of the shares vested on July 4, 2020, and the remaining shares vested in 36 equal monthly installments thereafter.

	/s/ Jacquelyn Sumer, Attorney-in-Fact	11/06/2026
	** 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.
* Form 4: SEC 1474 (03-26)