Form 3 Filing for LeonaBio, Inc. - Ownership Change

This filing reports a change in beneficial ownership for David J. Portman, with LeonaBio, Inc. (LONA). Mr. Portman, identified by CIK 0002126186, is filing as a 10% owner. The filing specifically addresses a warrant held by Sermonix Pharmaceuticals, Inc., where Mr. Portman serves as CEO. While Mr. Portman has voting control over the securities, his personal indirect beneficial ownership does not exceed 10% of the issuer's stock. The warrant, which does not expire, has an exercise date of October 26, 2026, and an exercise price of $0.001. It is convertible into 5,502,402 shares of Common Stock. The filing date is September 3, 2026, based on the owner's signature date, with the period of report being August 24, 2026.