Cartesian Therapeutics, Inc. Insider Trading Activity

Cartesian Therapeutics, Inc. (RNAC) reported an insider transaction by a director on 11/18/2025.

Rhea-AI Filing Summary

Cartesian Therapeutics, Inc. (RNAC) reported an insider transaction by a director on 11/18/2025. The director gifted 20,000 shares of common stock, reported with transaction code G at a stated price of $0 per share, which is typical for a charitable or family transfer. After this transaction, the director held 53,533 shares directly. Additional shares are reported as indirectly held, including 383,796 shares in a trust for the benefit of the director’s spouse and children, as well as other trusts and custodial accounts for family members.

Insider Trade Summary

20,000 shares gifted

Gift 7 txns

Insider Singer Michael

Role Director

Type	Security	Shares	Price	Value
Gift	Common Stock	20,000	$0.00	$0.00
holding	Common Stock	--	--	--
holding	Common Stock	--	--	--
holding	Common Stock	--	--	--
holding	Common Stock	--	--	--
holding	Common Stock	--	--	--
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 53,533 shares (Direct); Common Stock — 447,642 shares (Indirect, by trust); Common Stock — 14,788 shares (Indirect, by spouse); Common Stock — 192,438 shares (Indirect, as custodian)

Footnotes (6)

1. F1. Shares are held in a trust for the benefit of the reporting person's spouse and children. The reporting person's spouse is a trustee of the trust.
2. F2. Shares are held in a trust for which the reporting person is a beneficiary. The reporting person is a trustee of the trust.
3. F3. Shares are held in a trust for which the reporting person is a beneficiary. The reporting person's spouse is a trustee of the trust.
4. F4. Shares are held by the reporting person's spouse.
5. F5. The shares are held for LS, the child of the reporting person, through a custodial account established pursuant to the Uniform Transfer to Minors Act ("UTMA") for which the reporting person serves as custodian.
6. F6. The shares are held for SS, the child of the reporting person, through a custodial account established pursuant to the UTMA for which the reporting person serves as custodian.

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Accepted by SEC EDGAR 11/19/2025 - 06:35 PM EST Learn about SEC filing dates

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).

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^*

Singer Michael

(Last) (First) (Middle)

C/O CARTESIAN THERAPEUTICS, INC.

7495 NEW HORIZON WAY

(Street)

FREDERICK MD 21703

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Cartesian Therapeutics, Inc. [ RNAC ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
11/18/2025

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	11/18/2025		G		20,000	D	$0	53,533	D
Common Stock								383,796	I	by trust(1)
Common Stock								56,719	I	by trust(2)
Common Stock								7,127	I	by trust(3)
Common Stock								14,788	I	by spouse(4)
Common Stock								96,219	I	as custodian(5)
Common Stock								96,219	I	as custodian(6)

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. Shares are held in a trust for the benefit of the reporting person's spouse and children. The reporting person's spouse is a trustee of the trust.

2. Shares are held in a trust for which the reporting person is a beneficiary. The reporting person is a trustee of the trust.

3. Shares are held in a trust for which the reporting person is a beneficiary. The reporting person's spouse is a trustee of the trust.

4. Shares are held by the reporting person's spouse.

5. The shares are held for LS, the child of the reporting person, through a custodial account established pursuant to the Uniform Transfer to Minors Act ("UTMA") for which the reporting person serves as custodian.

6. The shares are held for SS, the child of the reporting person, through a custodial account established pursuant to the UTMA for which the reporting person serves as custodian.

Remarks:

	/s/ Matthew Bartholomae, Attorney-in-Fact for Michael Singer	11/19/2025
	** 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.