Michael Singer of Cartesian (NASDAQ: RNAC) reports new options and RSUs

Rhea-AI Filing Summary

Cartesian Therapeutics director Michael Singer reported new equity awards from the company, including 7,800 stock options and 2,600 restricted stock units granted on January 2, 2026. The stock options give him the right to buy 7,800 shares of common stock at $6.76 per share, become exercisable on January 2, 2027, and expire on January 1, 2036. The restricted stock units represent contingent rights to receive 2,600 shares of common stock that will vest in full on January 2, 2027. Following these awards, he directly holds 56,133 common shares and has additional indirect holdings through several trusts, his spouse, and custodial accounts for his children.

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)
01/02/2026

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	01/02/2026		A		2,600	A(1)	$0	56,133	D
Common Stock								383,796	I	by trust(2)
Common Stock								56,719	I	by trust(3)
Common Stock								7,127	I	by trust(4)
Common Stock								14,788	I	by spouse(5)
Common Stock								96,219	I	as custodian(6)
Common Stock								96,219	I	as custodian(7)

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)	$6.76	01/02/2026		A		7,800		01/02/2027	01/01/2036	Common Stock	7,800	$0	7,800	D

Explanation of Responses:

1. Each Restricted Stock Unit represents a contingent right to receive one share of common stock, which will vest in full on January 2, 2027.

2. 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.

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

4. 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.

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

6. 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.

7. 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	01/06/2026
	** 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.

FAQ

What insider transactions did Cartesian Therapeutics (RNAC) director Michael Singer report?

On January 2, 2026, director Michael Singer reported an award of 7,800 stock options and 2,600 restricted stock units related to Cartesian Therapeutics common stock.

What are the terms of Michael Singer's new stock options at Cartesian Therapeutics (RNAC)?

The 7,800 stock options have an exercise price of $6.76 per share, become exercisable on January 2, 2027, and expire on January 1, 2036.

How do Michael Singer’s 2,600 restricted stock units at RNAC vest?

Each restricted stock unit gives a contingent right to receive one share of common stock, with all 2,600 units vesting in full on January 2, 2027.

How many Cartesian Therapeutics (RNAC) shares does Michael Singer hold directly after these awards?

After the reported transactions, Michael Singer directly holds 56,133 shares of Cartesian Therapeutics common stock.

What indirect holdings in Cartesian Therapeutics (RNAC) are associated with Michael Singer?

Indirect holdings include shares held by multiple trusts, by his spouse, and through custodial accounts for his children established under the UTMA.

Did Michael Singer pay cash for the reported RNAC equity awards?

The Form 4 shows the 2,600 common-stock-linked units and 7,800 stock options with a reported transaction price of $0.00 for the awards themselves.