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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(Print or Type Responses)

1. Name and Address of Reporting Person * Portman David J. 2. Issuer Name and Ticker or Trading Symbol LeonaBio, Inc. [LONA] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 250 E. BROAD ST., SUITE 250 3. Date of Earliest Transaction (Month/Day/Year) 10/26/2026 (Street) COLUMBUS, OH 43215 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 10/26/2026 10/26/2026 P 3,149,470 A $3,149.47 3,149,470 I See note

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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

Warrant(1)

$0.001

10/26/2026

10/26/2026

P

5,502,402

10/26/2026

(2)

Common Stock

5,502,402

$3,149.47

0

I

See note(3)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Portman David J. 250 E. BROAD ST., SUITE 250 COLUMBUS, OH 43215		X

Signatures

David J. Portman		10/28/2026
**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)	The shares are held by Sermonix Pharmaceuticals, Inc. of which Dr. Portman is the Chief Executive Officer. This Form 4 is being filed to report Dr. Portman's voting control over such securities, but Dr. Portman's personal indirect beneficial ownership does not exceed 10% of the stock in the Issuer.
(2)	The Warrant does not expire.
(3)	The Warrant was held by Sermonix Pharmaceuticals, Inc. of which Dr. Portman is the Chief Executive Officer. The Warrant was exercised on October 26, 2026, in part, into 3,149,740 Common Shares of Issuer, and the balance of the Warrant was assigned to Perceptive Xentogeny Venture Fund II, LP as a distribution-in-kind pursuant to a plan of distribution to the Sermonix Pharmaceuticals equity holders. Following the partial exercise and the assignment of the remaining Warrant rights, Sermonix Pharmaceuticals holds 3,149,740 Common Shares of Issuer.

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