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 OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	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* Portman David J. (Last) (First) (Middle) 250 E. BROAD ST., SUITE 250 (Street) COLUMBUS OH 43215 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol LeonaBio, Inc. [ LONA ] Foreign Trading Symbol	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 10/26/2026
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) 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	10/26/2026	10/26/2026	P		3,149,470	A	$3,149.47	3,149,470	I	See note

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
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)

Explanation of Responses:

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.

	David J. Portman	10/28/2026
	** 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).
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