Cartesian Therapeutics (RNAC) director reports new stock and option grants

Rhea-AI Filing Summary

Cartesian Therapeutics director and 10% owner Murat Kalayoglu reported new equity awards. On January 2, 2026, he received 2,600 shares of common stock in the form of restricted stock units, each representing one share that will vest in full on January 2, 2027. He also was granted a stock option for 7,800 shares of common stock at an exercise price of $6.76 per share, exercisable starting January 2, 2027 and expiring January 1, 2036.

After these transactions, he directly beneficially owned 511,577 shares of Cartesian Therapeutics common stock and held an additional 4,555,260 shares indirectly through a trust for the benefit of his spouse and 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

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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^*

Kalayoglu Murat

(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	X	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	511,577	D
Common Stock								4,555,260	I	by trust(2)

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 (the "Trust") for the benefit of the reporting person's spouse and children. The reporting person's spouse is a trustee of the trust.

Remarks:

	/s/ Matthew Bartholomae, Attorney-in-Fact for Murat Kalayoglu	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 RNAC director Murat Kalayoglu report?

He reported receiving 2,600 restricted stock units, each equal to one share of Cartesian Therapeutics common stock, and a stock option for 7,800 shares at an exercise price of $6.76 per share on January 2, 2026.

When do Murat Kalayoglu’s RNAC restricted stock units vest?

The 2,600 restricted stock units will vest in full on January 2, 2027, at which time each unit entitles him to receive one share of Cartesian Therapeutics common stock.

What are the key terms of Murat Kalayoglu’s RNAC stock option grant?

The stock option covers 7,800 shares of Cartesian Therapeutics common stock at an exercise price of $6.76 per share. It becomes exercisable on January 2, 2027 and expires on January 1, 2036.

How many RNAC shares does Murat Kalayoglu own directly and indirectly?

Following the reported transactions, he directly beneficially owned 511,577 shares of Cartesian Therapeutics common stock and indirectly beneficially owned 4,555,260 shares held by a trust for the benefit of his spouse and children.

What is Murat Kalayoglu’s relationship to Cartesian Therapeutics (RNAC)?

He is reported as a director and a 10% owner of Cartesian Therapeutics, Inc., indicating a significant ownership and governance role at the company.

How are the indirectly held RNAC shares structured for Murat Kalayoglu?

The 4,555,260 indirectly owned shares are held in a trust for the benefit of his spouse and children, with his spouse serving as a trustee of the trust.