Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 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 that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES 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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1. Name and Address of Reporting Person * HEALY JAMES 2. Issuer Name and Ticker or Trading Symbol Seaport Therapeutics, Inc. [SPTX] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) SEAPORT THERAPEUTICS, INC., 101 SEAPORT BLVD., FLOOR 12 3. Date of Earliest Transaction (Month/Day/Year) 05/04/2026 (Street) BOSTON, MA 02210 4. If Amendment, Date 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 (City) (State) (Zip) 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 05/04/2026 C 1,927,159 A (1) 1,927,159 I By Sofinnova Venture Partners XI, L.P.(2) Common Stock 05/04/2026 C 804,379 A (1) 2,731,538 I By Sofinnova Venture Partners XI, L.P.(2)

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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 Underlying Securities (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 of Derivative Security: 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

Series A-2 Preferred Stock

(1)

05/04/2026

C

6,052,631

(1)

(1)

Common Stock

1,927,159

$ 0

0

I

By Sofinnova Venture Partners XI, L.P.(2)

Series B Preferred Stock

(1)

05/04/2026

C

2,526,315

(1)

(1)

Common Stock

804,379

$ 0

0

I

By Sofinnova Venture Partners XI, L.P.(2)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
HEALY JAMES SEAPORT THERAPEUTICS, INC. 101 SEAPORT BLVD., FLOOR 12 BOSTON, MA 02210	X

Signatures

/s/ Lana Gladstein, Attorney-in-Fact		05/04/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	Each share of Series A-2 and Series B Preferred Stock (collectively, the "Preferred Stock") was convertible into Common Stock of the Issuer on a one-for-3.1407 basis at the option of the holder, and automatically converted upon the closing of the Issuer's initial public offering without payment of further consideration. The Preferred Stock had no expiration date.
(2)	These shares are directly held by Sofinnova Venture Partners XI, L.P. ("SVP XI"). Sofinnova Management XI, L.P. ("SM XI LP") is the general partner of SVP XI, and Sofinnova Management XI, L.L.C. ("SM XI") is the general partner of SM XI LP. The Reporting Person is a managing member of SM XI and may be deemed to share voting and investment discretion with respect to securities directly held by SVP XI. The Reporting Person disclaims beneficial ownership of the securities directly held by SVP XI. This report shall not be construed as an admission that he is the beneficial owner of the securities reported herein for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose, except to the extent of his pecuniary interest therein, if any.

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