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 * PERCEPTIVE ADVISORS LLC 2. Issuer Name and Ticker or Trading Symbol LeonaBio, Inc. [LONA] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 51 ASTOR PLACE, 10TH FLOOR 3. Date of Earliest Transaction (Month/Day/Year) 10/26/2026 (Street) NEW YORK, NY 10003 4. If Amendment, Date Original Filed (Month/Day/Year) 6. Individual or Joint/Group Filing (Check Applicable Line) ___ Form filed by One Reporting Person _X_ 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 M 776,648 A $0.001 776,648 I See Footnotes(1)(7) Common Stock 1,529,566 I See Footnotes(2)(7) Common Stock 329,756 I See Footnotes(3)(7)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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

Pre-Funded Warrant (right to buy)

$0.001

10/26/2026

M

776,648

(4)(5)

(6)

Common Stock

776,648

(4)

0

I

See Footnotes(1)(7)

Pre-Funded Warrant (right to buy)

$0.001

12/23/2025(9)

(6)

Common Stock

457,645

457,645

I

See Footnotes(3)(7)

Pre-Funded Warrant (right to warrant)

$0.001

12/23/2025(9)

(6)

Common Stock

1,372,935

1,372,935

I

See Footnotes(2)(7)

Pre-Funded Warrant (right to buy)

$0.001

(4)(9)

(6)

Common Stock

2,352,932

2,352,932

I

See Footnotes(3)(7)(8)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
PERCEPTIVE ADVISORS LLC 51 ASTOR PLACE, 10TH FLOOR NEW YORK, NY 10003	X	X
EDELMAN JOSEPH 51 ASTOR PL, 10TH FLOOR NEW YORK, NY 10003	X	X
PERCEPTIVE LIFE SCIENCES MASTER FUND LTD 51 ASTOR PLACE, 10TH FLOOR NEW YORK, NY 10003	X	X

Signatures

/s/ Joseph Edelman - for Perceptive Advisors LLC, By: Joseph Edelman, its managing member		10/26/2026
**Signature of Reporting Person		Date
/s/ Joseph Edelman - for Perceptive Life Sciences Master Fund Ltd., By: Perceptive Advisors LLC, its investment manager, By: Joseph Edelman, its managing member		10/26/2026
**Signature of Reporting Person		Date
/s/ Joseph Edelman		10/26/2026
**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 securities are directly held by Sermonix Pharmaceuticals, Inc. ("Sermonix"). An affiliate of Perceptive Advisors LLC (the "Advisor") currently holds approximately 29% of the outstanding capital stock of Sermonix (excluding securities convertible into shares of Sermonix capital stock). Pursuant to General Instruction 4.b.(iv) of Form 4, the Reporting Persons with this filing have reported the entire amount of Sermonix's interest in the securities, rather than the Reporting Person's proportionate interest in the securities held by Sermonix.
(2)	The securities are directly held by Perceptive Life Sciences Master Fund Ltd. (the "Master Fund"). The Advisor serves as the investment manager of Master Fund. Joseph Edelman is the managing member of the Advisor.
(3)	The securities are directly held by Perceptive Xontogeny Venture Fund II, LP ("PXV II"). Perceptive Venture Advisors, LLC serves as the investment manager of PXV II and is controlled by the Advisor, and Perceptive Xontogeny Venture II GP, LLC ("PXV GP") is the general partner of PXV II. Mr. Edelman is the managing member of PXV GP and the Advisor.
(4)	The securities were issued to Sermonix in exchange for the grant of certain licenses and rights by Sermonix to the Issuer. The Pre-Funded Warrants became exercisable on March 18, 2026 upon receipt by the Issuer of stockholder approval such that the Pre-Funded Warrants can be exercised at any time without restriction or additional stockholder approval.
(5)	The Pre-Funded Warrants may not be exercised if, after such exercise, Sermonix, together with its Attribution Parties (as defined in the warrants) would beneficially own, as determined in accordance with Section 13(d) of the Securities Exchange Act of 1934, as amended, more than 49.99% of the shares of Common Stock then issued and outstanding after giving effect to such exercise.
(6)	The Pre-Funded Warrants do not expire.
(7)	Each of Mr. Edelman, the Advisor, the Master Fund and PXV II disclaims, for purposes of Section 16 of the Securities Exchange Act of 1934, beneficial ownership of such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that any of the Reporting Persons is the beneficial owner of such securities for purposes of Section 16 or for any other purposes.
(8)	On October 26, 2026, PXV II received from Sermonix Pre-Funded Warrants exercisable for 2,352,932 shares of Common Stock pursuant to a distribution of securities held by Sermonix to holders of Sermonix common stock.
(9)	The Pre-Funded Warrants may not be exercised if, after such exercise, the Master Fund or PVX II, together with its Attribution Parties (as defined in the warrants) would beneficially own, as determined in accordance with Section 13(d) of the Securities Exchange Act of 1934, as amended, more than 19.99% of the shares of Common Stock then issued and outstanding after giving effect to such exercise (the "Beneficial Ownership Limitation"). As of the date hereof, the Beneficial Ownership Limitation does not permit the Master Fund or PXV II to exercise any of its Warrants.

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