SEC FORM 4

SEC FORM 4 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

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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

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)
11/13/2023

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Series A Convertible Preferred Stock	11/15/2023		A		24,785.081	A	$403.4685	24,785.081	I	See Footnote⁽¹⁾
Series A Convertible Preferred Stock	11/15/2023		A		123,925.407	A	$403.4685	123,925.407	D
Common Stock								86,418	I	By wife
Common Stock								7,293,625	D
Common Stock								29,868,490	I	See Footnote⁽¹⁾

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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Stock Option (Right to Buy)	$17.47	11/13/2023		D			6,410	⁽²⁾	06/15/2027	Common Stock	6,410	⁽²⁾	0	D
Stock Option (Right to Buy)	$12.75	11/13/2023		D			10,000	⁽³⁾	06/14/2028	Common Stock	10,000	⁽³⁾	0	D
Stock Option (Right to Buy)	$2.1	11/13/2023		D			10,000	⁽⁴⁾	06/13/2029	Common Stock	10,000	⁽⁴⁾	0	D
Stock Option (Right to Buy)	$3	11/13/2023		D			20,000	⁽⁵⁾	06/18/2030	Common Stock	20,000	⁽⁵⁾	0	D
Stock Option (Right to Buy)	$4.01	11/13/2023		D			40,000	⁽⁶⁾	03/29/2031	Common Stock	40,000	⁽⁶⁾	0	D
Stock Option (Right to Buy)	$3.31	11/13/2023		D			40,000	⁽⁷⁾	01/02/2032	Common Stock	40,000	⁽⁷⁾	0	D
Stock Option (Right to Buy)	$1.13	11/13/2023		D			75,000	⁽⁸⁾	01/01/2033	Common Stock	75,000	$0.93	0	D

Explanation of Responses:

1. 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.

2. This option, which provided for vesting in full on June 14, 2018, was canceled in the merger (the "Merger") between Selecta Biosciences, Inc. and Cartesian Therapeutics, Inc.

3. This option, which provided for vesting in full on June 13, 2019, was canceled in the Merger.

4. This option, which provided for vesting in full on June 14, 2020, was canceled in the Merger.

5. This option, which provided for vesting in full on June 17, 2021, was canceled in the Merger.

6. This option, which provided for vesting in full on March 30, 2022, was canceled in the Merger.

7. This option, which provided for vesting in full on January 3, 2023, was canceled in the Merger.

8. This option, which provided for vesting in full on January 2, 2024, was canceled in the Merger in exchange for a cash payment of $69,750, representing the difference between the exercise price of the option and $2.06, the Cash-out Amount as applied in the Merger.

Remarks:

	/s/ Matthew Bartholomae, Attorney-in-Fact for Timothy A. Springer	11/15/2023
	** 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.

Springer Timothy A was granted 148,710 units of Series A Convertible Preferred Stock (SEC Form 4)