SEC Form 424B3 filed by Estrella Immunopharma Inc.

Filed Pursuant to Rule 424(b)(3)

Registration No. 333-274931

Prospectus Supplement No. 13

(To Prospectus Dated December 28, 2023)

ESTRELLA IMMUNOPHARMA, INC.

3,829,338 Shares of Common Stock

Up to 7,036,726 Shares of Common Stock

Up to 2,215,000 Shares of Common Stock Issuable Upon Exercise of Warrants

This prospectus supplement no. 13 and the prospectus, dated December 28, 2023 (as supplemented by prospectus supplement no. 1, dated February 12, 2024, prospectus supplement no. 2, dated February 15, 2024, prospectus supplement no. 3, dated March 7, 2024, prospectus supplement no. 4, dated March 8, 2024, prospectus supplement no. 5, dated May 15, 2024, prospectus supplement no. 6, dated July 2, 2024, prospectus supplement no. 7, dated August 6, 2024, prospectus supplement no. 8, dated August 21, 2024, prospectus supplement no. 9, dated October 1, 2024, prospectus supplement no. 10, dated November 18, 2024, prospectus supplement no. 11, dated November 27, 2024, and prospectus supplement no. 12, dated December 9, 2024, the “Prospectus”), which form a part of our registration statement on Form S-1 (No. 333-274931), relate to the resale from time to time of certain shares of common stock (“Common Stock”) of Estrella Immunopharma, Inc. (“we,” “us,” “our” the “Company” and “Estrella”). These shares include (a) 3,829,338 shares of Common Stock held by the Selling Stockholders as more fully described in the Prospectus, (b) up to 7,036,726 shares of Common Stock that may be issued and sold by us to White Lion Capital, LLC pursuant to a Common Stock Purchase Agreement, as more fully described in the Prospectus and (c) up to 2,215,000 shares of Common Stock issuable to the holders of redeemable warrants (“Warrants”) upon the exercise thereof at an exercise price of $11.50 per share, as more fully described in the Prospectus.

This prospectus supplement is being filed to update and supplement the information contained in the Prospectus with the information contained in the current report on Form 8-K filed by the Company on December 16, 2024 (the “Current Report”). Accordingly, we have attached the Current Report to this prospectus supplement.

You should read this prospectus supplement in conjunction with the Prospectus, including any amendments or supplements thereto. This prospectus supplement is qualified by reference to the Prospectus except to the extent that the information provided by this prospectus supplement supersedes information contained in the Prospectus. This prospectus supplement is not complete without, and may not be delivered or used except in conjunction with, the Prospectus, including any amendments or supplements thereto.

Our Common Stock and Warrants are traded on the Nasdaq Capital Market (“Nasdaq”) under the symbols “ESLA” and “ESLAW,” respectively. On December 16, 2024, the closing price of our Common Stock on Nasdaq was $1.27 per share and the closing price of our Warrants on Nasdaq was $0.091 per Warrant.

Investing in our securities is highly speculative and involves a high degree of risk. See “Risk Factors” beginning on page 7 of the Prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if the Prospectus or this prospectus supplement is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is December 17, 2024.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): December 16, 2024

Estrella Immunopharma, Inc.

(Exact name of registrant as specified in its charter)

(510) 318-9098

(Registrant’s telephone number, including area code)

N/A

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Securities registered pursuant to Section 12(b) of the Act.

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933(§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange

Act. ☐

Item 8.01. Other Events.

As previously disclosed, on November 19, 2024, Estrella Immunopharma, Inc. (the “Company”) received a notification letter (the “Stockholders’ Equity Requirement Notice”) from the Nasdaq Stock Market LLC (“Nasdaq”) notifying the Company that it was not in compliance with the minimum stockholders’ equity requirement for continued listing on The Nasdaq Capital Market as set forth in Nasdaq Listing Rule 5550(b)(1) (the “Stockholders’ Equity Requirement”). On December 11, 2024, the Company received a notification letter from Nasdaq stating that for the last 10 consecutive business days, from November 25, 2024 to December 10, 2024, the Company’s market value of listed securities has been $35,000,000 or greater. Accordingly, the Company has regained compliance with the Stockholders’ Equity Requirement, and this matter is now closed.

Additionally, as previously disclosed, on November 19, 2024, the Company received a notification letter (the “Minimum Bid Price Deficiency Notice”) from Nasdaq notifying the Company that it was not in compliance with Nasdaq’s Listing Rule 5550(a)(2), as the minimum bid price of the Company’s common stock has been below $1.00 per share for 30 consecutive business days (the “Minimum Bid Price Requirement”). On December 11, 2024, the Company received a notification letter from Nasdaq stating that for the last 10 consecutive business days, from November 25, 2024 to December 10, 2024, the closing bid price of the Company’s common stock has been at $1.00 per share or greater. Accordingly, the Company has regained compliance with the Minimum Bid Price Requirement, and this matter is now closed.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.