Estrella Immunopharma Offers Up To 2,541,206 Shares For Resale By The Selling Stockholders

ESTRELLA IMMUNOPHARMA, INC.

Up to 2,541,206 Shares of Common Stock

This prospectus relates to the offer and resale from time to time by the selling stockholders named in this prospectus (the "Selling Stockholders") of up to 2,541,206 shares of our Common Stock. This amount includes (i) shares issued to certain Selling Stockholders in private placements and (ii) up to an aggregate of 735,857 additional shares of Common Stock that may be issuable to certain Selling Stockholders pursuant to contingent "true-up" provisions in the May-June 2025 and September 2025 subscription agreements, in each case subject to the terms and conditions of those agreements.

The shares being registered for resale by this prospectus represent approximately 6.7% of our total outstanding shares of Common Stock as of December 1, 2025. We provide more information about how the Selling Stockholders may sell the shares of Common Stock in the section titled "Plan of Distribution."

Estrella's Common Stock is traded on the Nasdaq Capital Market ("Nasdaq") under the symbol "ESLA." On December 19, 2025, the closing price of our Common Stock was $1.69 per share.