Cartesian Therapeutics (NASDAQ: RNAC) director gets equity grants awards

Rhea-AI Filing Summary

Cartesian Therapeutics, Inc. director and 10% owner Timothy A. Springer reported new equity awards. On January 2, 2026, he received 2,600 shares of common stock at a price of $0 through restricted stock units that will vest in full on January 2, 2027. He was also 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. Following these awards, he directly beneficially owned 8,646,285 shares of common stock, with additional indirect holdings of 330,695 shares by his wife and 656,513 shares held by TAS Partners LLC, for which he is managing member and disclaims beneficial ownership except to the extent of any pecuniary interest.

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^*

SPRINGER TIMOTHY A

(Last) (First) (Middle)

36 WOODMAN ROAD

(Street)

CHESTNUT HILL MA 02467

(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	8,646,285	D
Common Stock								330,695	I	By wife
Common Stock								656,513	I	See Footnote(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. Held by TAS Partners LLC. The reporting person is the managing member of TAS Partners LLC. The reporting person disclaims beneficial ownership of the securities held by TAS Partners LLC except to the extent of his pecuniary interest therein, if any.

Remarks:

	/s/ Matthew Bartholomae, Attorney-in-Fact for Timothy A. Springer	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 Timothy A. Springer report?

Timothy A. Springer, a director and 10% owner of Cartesian Therapeutics, Inc. (RNAC), reported receiving 2,600 shares of common stock at $0 via restricted stock units and a stock option for 7,800 shares with a $6.76 exercise price, all dated January 2, 2026.

How many RNAC shares does Timothy A. Springer own after these transactions?

After the reported transactions, Timothy A. Springer directly beneficially owned 8,646,285 shares of Cartesian Therapeutics common stock. He also had indirect holdings of 330,695 shares held by his wife and 656,513 shares held by TAS Partners LLC.

What are the terms of Timothy A. Springer’s new RNAC stock option grant?

The new grant is a stock option for 7,800 shares of Cartesian Therapeutics common stock with an exercise price of $6.76 per share. It becomes exercisable on January 2, 2027 and expires on January 1, 2036.

How do the RNAC restricted stock units for Timothy A. Springer vest?

Each restricted stock unit represents a right to receive one share of Cartesian Therapeutics common stock. The 2,600 restricted stock units reported will vest in full on January 2, 2027.

How are Timothy A. Springer’s indirect RNAC holdings structured?

Indirect holdings include 330,695 shares held by his wife and 656,513 shares held by TAS Partners LLC. He is the managing member of TAS Partners LLC and disclaims beneficial ownership of those LLC-held securities except to the extent of any pecuniary interest.

Was the RNAC Form 4 filed by one or multiple reporting persons?

The Form 4 was filed by one reporting person, identified as Timothy A. Springer, who is a director and 10% owner of Cartesian Therapeutics, Inc.