Organization and Business Operations	3 Months Ended
Mar. 31, 2026
Organization and Business Operations [Abstract]
Organization and Business Operations	Note 1 – Organization and Business Operations Description of Business Estrella Immunopharma, Inc. (“Estrella”), a Delaware corporation, is a clinical-stage biopharmaceutical company developing T-cell therapies with the capacity to potentially cure patients with blood cancers and solid tumors. Estrella was incorporated in the State of Delaware on March 30, 2022 by Eureka Therapeutics, Inc. (“Eureka”), which was incorporated in California in February 2006 and reincorporated in Delaware in March 2018 and is the predecessor of Estrella. On June 28, 2022, pursuant to a Contribution Agreement between Estrella and Eureka (the “Contribution Agreement”), Eureka contributed certain assets (the “Assets”) related to T-cell therapies targeting CD19 and CD22, proteins expressed on the surface of almost all B-cell leukemias and lymphomas, in exchange for 105,000,000 shares of Estrella’s Series AA Preferred Stock (the “Separation”). As part of the Separation, Estrella entered into a License Agreement (the “License Agreement”) with Eureka and Eureka Therapeutics (Cayman) Ltd. (“Eureka Cayman”), an affiliate of Eureka, and a Services Agreement (the “Services Agreement”) with Eureka, and Eureka contributed and assigned the Collaboration Agreement between Eureka and Imugene Limited (“Imugene”) (the “Collaboration Agreement”) to Estrella. The License Agreement grants the Company an exclusive license to develop CD19 and CD22 targeted T-cell therapies using Eureka’s ARTEMIS® platform. Under the Services Agreement, Eureka has agreed to perform certain services for the Company in connection with the development of the Company’s product candidates, EB103 and EB104. EB103, which is a T-cell therapy also called “CD19-Redirected ARTEMIS® T-Cell Therapy,” utilizes Eureka’s ARTEMIS® technology to target CD19. The Company is also developing EB104, a T-cell therapy also called “CD19/22 Dual-Targeting ARTEMIS® T-Cell Therapy.” Like EB103, EB104 utilizes Eureka’s ARTEMIS® technology to target not only CD19, but also CD22. The Collaboration Agreement establishes the partnership between the Company and Imugene related to development of solid tumor treatments using Imugene’s product candidate (“CF33-CD19t”) in conjunction with EB103. On March 2, 2023, the FDA cleared Estrella’s IND application for EB103, allowing Estrella to proceed with the Phase I/II STARLIGHT-1 Clinical Trial (“STARLIGHT-1”). On March 4, 2024, the Company, Estrella and Eureka executed Statement of Work No. 001 (“SOW”) relating to clinical trial services to be performed by Eureka in connection with the STARLIGHT-1 clinical trial. On May 13, 2024, the Company and Eureka entered into Amendment No. 1 to the Statement of Work, effective as of March 4, 2024 (see Note 5). In November 2025, the Company announced the completion of Phase I dosing for the STARLIGHT-1 clinical trial. As of March 31, 2026, nine patients have been dosed in Phase I of the STARLIGHT-1 clinical trial, and one Phase II patient was dosed in January 2026. On September 29, 2023 (the “Closing Date”), Estrella and TradeUP Acquisition Corp. (“UPTD”) consummated the business combination (the “Business Combination”) pursuant to the terms of the Agreement and Plan of Merger, dated as of September 30, 2022 (the “Merger Agreement”), by and among UPTD, Tradeup Merger Sub Inc., a Delaware corporation and wholly-owned subsidiary of UPTD (“Merger Sub”), and the Company. Pursuant to the terms of the Merger Agreement, Merger Sub merged with and into Estrella, with Estrella surviving as a wholly-owned subsidiary of UPTD. Upon closing of the Business Combination, UPTD changed its corporate name to Estrella Immunopharma, Inc. (“New Estrella” or the “Company”). Estrella’s fiscal year end was June 30, and the Company’s fiscal year end changed from December 31 to June 30 effective as of the Closing Date. On June 26, 2024, the Company filed a Certificate of Ownership and Merger with the Delaware Secretary of State to effect a merger (the “Merger 1”) with its wholly-owned subsidiary, Estrella BioPharma Inc., pursuant to Section 253 of the Delaware General Corporation Law. The Merger 1 was approved by resolutions duly adopted by the unanimous written consent of the Company’s board of directors. The Merger 1 became effective at 11:59 PM Eastern Time on June 30, 2024, at which time the separate existence of Estrella BioPharma Inc. ceased, and the Company became the surviving corporation. In November 2024, the Company established Estrella Immunopharma (Hong Kong) Co. Ltd (“Estrella HK”) as a wholly-owned subsidiary in Hong Kong. This subsidiary was created to facilitate strategic collaborations and provide a local presence to support the Company’s operations and initiatives in Asia. As of March 31, 2026, Estrella HK had not commenced any operations. On January 7, 2026, the Company received a notice from the Listing Qualifications Department of The Nasdaq Stock Market LLC (“Nasdaq”) stating that the Company was not in compliance with Nasdaq Listing Rule 5620(a) because it had not held an annual meeting of shareholders within twelve months of the end of its transition period ended December 31, 2024. On February 27, 2026, Nasdaq notified the Company that it has granted an extension until June 29, 2026 to regain compliance with this requirement. Pursuant to the Company’s plan of compliance submitted to Nasdaq on February 24, 2026, the Company intends to hold a joint 2025/2026 annual meeting of shareholders prior to such deadline. Going Concern In assessing the Company’s liquidity and the substantial doubt about its ability to continue as a going concern, the Company monitors and analyzes cash on hand and operating expenditure commitments. The Company’s liquidity needs are to meet working capital requirements and operating expense obligations. The Company’s management has considered whether there is substantial doubt about its ability to continue as a going concern based on the following factors: (1) recurring losses from operations of approximately $2.3 million for the three months ended March 31, 2026; (2) an accumulated deficit of approximately $39.3 million as of March 31, 2026; (3) net cash used in operating activities of approximately $6.7 million for the three months ended March 31, 2026. The Company has expended substantial funds on its research and development business, has experienced losses and negative cash flows from operations since its inception and expects losses and negative cash flows from operations to continue until its technology receives regulatory approval and the Company generates sufficient revenue and positive cash flow from operations, which may never occur. The Company’s ability to fund its operations is dependent on the amount of cash on hand and its ability to raise debt or additional equity financing, which may not be successful, available on acceptable terms, or available at all. From May 2025 to September 2025, the Company entered into securities purchase agreements with certain investors, pursuant to which the Company issued 1,600,000 shares of common stock and received gross proceeds of approximately $2.4 million. Additionally, the Company consummated a registered direct offering and a concurrent private placement on January 6, 2026, resulting in gross proceeds of approximately $8.0 million. Despite these financing activities, the Company’s management is of the opinion that it will not have sufficient funds to meet the Company’s working capital requirements and debt obligations as they become due starting from one year from the issuance of these unaudited condensed consolidated financial statements due to the recurring loss. As a result, management has determined that there is a substantial doubt about its ability to continue as a going concern. If the Company is unable to obtain adequate financing or generate significant revenue, it may be required to curtail or cease its operations.

Organization and Business Operations

3 Months Ended

Mar. 31, 2026

Organization and Business Operations [Abstract]

Note 1 – Organization and Business Operations

Description of Business

Estrella Immunopharma, Inc. (“Estrella”), a Delaware corporation, is a clinical-stage biopharmaceutical company developing T-cell therapies with the capacity to potentially cure patients with blood cancers and solid tumors.

Estrella was incorporated in the State of Delaware on March 30, 2022 by Eureka Therapeutics, Inc. (“Eureka”), which was incorporated in California in February 2006 and reincorporated in Delaware in March 2018 and is the predecessor of Estrella.

On June 28, 2022, pursuant to a Contribution Agreement between Estrella and Eureka (the “Contribution Agreement”), Eureka contributed certain assets (the “Assets”) related to T-cell therapies targeting CD19 and CD22, proteins expressed on the surface of almost all B-cell leukemias and lymphomas, in exchange for 105,000,000 shares of Estrella’s Series AA Preferred Stock (the “Separation”).

As part of the Separation, Estrella entered into a License Agreement (the “License Agreement”) with Eureka and Eureka Therapeutics (Cayman) Ltd. (“Eureka Cayman”), an affiliate of Eureka, and a Services Agreement (the “Services Agreement”) with Eureka, and Eureka contributed and assigned the Collaboration Agreement between Eureka and Imugene Limited (“Imugene”) (the “Collaboration Agreement”) to Estrella. The License Agreement grants the Company an exclusive license to develop CD19 and CD22 targeted T-cell therapies using Eureka’s ARTEMIS® platform. Under the Services Agreement, Eureka has agreed to perform certain services for the Company in connection with the development of the Company’s product candidates, EB103 and EB104. EB103, which is a T-cell therapy also called “CD19-Redirected ARTEMIS® T-Cell Therapy,” utilizes Eureka’s ARTEMIS® technology to target CD19. The Company is also developing EB104, a T-cell therapy also called “CD19/22 Dual-Targeting ARTEMIS® T-Cell Therapy.” Like EB103, EB104 utilizes Eureka’s ARTEMIS® technology to target not only CD19, but also CD22. The Collaboration Agreement establishes the partnership between the Company and Imugene related to development of solid tumor treatments using Imugene’s product candidate (“CF33-CD19t”) in conjunction with EB103.

On March 2, 2023, the FDA cleared Estrella’s IND application for EB103, allowing Estrella to proceed with the Phase I/II STARLIGHT-1 Clinical Trial (“STARLIGHT-1”). On March 4, 2024, the Company, Estrella and Eureka executed Statement of Work No. 001 (“SOW”) relating to clinical trial services to be performed by Eureka in connection with the STARLIGHT-1 clinical trial. On May 13, 2024, the Company and Eureka entered into Amendment No. 1 to the Statement of Work, effective as of March 4, 2024 (see Note 5).

In November 2025, the Company announced the completion of Phase I dosing for the STARLIGHT-1 clinical trial. As of March 31, 2026, nine patients have been dosed in Phase I of the STARLIGHT-1 clinical trial, and one Phase II patient was dosed in January 2026.

On September 29, 2023 (the “Closing Date”), Estrella and TradeUP Acquisition Corp. (“UPTD”) consummated the business combination (the “Business Combination”) pursuant to the terms of the Agreement and Plan of Merger, dated as of September 30, 2022 (the “Merger Agreement”), by and among UPTD, Tradeup Merger Sub Inc., a Delaware corporation and wholly-owned subsidiary of UPTD (“Merger Sub”), and the Company. Pursuant to the terms of the Merger Agreement, Merger Sub merged with and into Estrella, with Estrella surviving as a wholly-owned subsidiary of UPTD. Upon closing of the Business Combination, UPTD changed its corporate name to Estrella Immunopharma, Inc. (“New Estrella” or the “Company”). Estrella’s fiscal year end was June 30, and the Company’s fiscal year end changed from December 31 to June 30 effective as of the Closing Date.

On June 26, 2024, the Company filed a Certificate of Ownership and Merger with the Delaware Secretary of State to effect a merger (the “Merger 1”) with its wholly-owned subsidiary, Estrella BioPharma Inc., pursuant to Section 253 of the Delaware General Corporation Law. The Merger 1 was approved by resolutions duly adopted by the unanimous written consent of the Company’s board of directors. The Merger 1 became effective at 11:59 PM Eastern Time on June 30, 2024, at which time the separate existence of Estrella BioPharma Inc. ceased, and the Company became the surviving corporation.

In November 2024, the Company established Estrella Immunopharma (Hong Kong) Co. Ltd (“Estrella HK”) as a wholly-owned subsidiary in Hong Kong. This subsidiary was created to facilitate strategic collaborations and provide a local presence to support the Company’s operations and initiatives in Asia. As of March 31, 2026, Estrella HK had not commenced any operations.

On January 7, 2026, the Company received a notice from the Listing Qualifications Department of The Nasdaq Stock Market LLC (“Nasdaq”) stating that the Company was not in compliance with Nasdaq Listing Rule 5620(a) because it had not held an annual meeting of shareholders within twelve months of the end of its transition period ended December 31, 2024. On February 27, 2026, Nasdaq notified the Company that it has granted an extension until June 29, 2026 to regain compliance with this requirement. Pursuant to the Company’s plan of compliance submitted to Nasdaq on February 24, 2026, the Company intends to hold a joint 2025/2026 annual meeting of shareholders prior to such deadline.

Going Concern

In assessing the Company’s liquidity and the substantial doubt about its ability to continue as a going concern, the Company monitors and analyzes cash on hand and operating expenditure commitments. The Company’s liquidity needs are to meet working capital requirements and operating expense obligations.

The Company’s management has considered whether there is substantial doubt about its ability to continue as a going concern based on the following factors: (1) recurring losses from operations of approximately $2.3 million for the three months ended March 31, 2026; (2) an accumulated deficit of approximately $39.3 million as of March 31, 2026; (3) net cash used in operating activities of approximately $6.7 million for the three months ended March 31, 2026. The Company has expended substantial funds on its research and development business, has experienced losses and negative cash flows from operations since its inception and expects losses and negative cash flows from operations to continue until its technology receives regulatory approval and the Company generates sufficient revenue and positive cash flow from operations, which may never occur. The Company’s ability to fund its operations is dependent on the amount of cash on hand and its ability to raise debt or additional equity financing, which may not be successful, available on acceptable terms, or available at all.

From May 2025 to September 2025, the Company entered into securities purchase agreements with certain investors, pursuant to which the Company issued 1,600,000 shares of common stock and received gross proceeds of approximately $2.4 million. Additionally, the Company consummated a registered direct offering and a concurrent private placement on January 6, 2026, resulting in gross proceeds of approximately $8.0 million. Despite these financing activities, the Company’s management is of the opinion that it will not have sufficient funds to meet the Company’s working capital requirements and debt obligations as they become due starting from one year from the issuance of these unaudited condensed consolidated financial statements due to the recurring loss. As a result, management has determined that there is a substantial doubt about its ability to continue as a going concern. If the Company is unable to obtain adequate financing or generate significant revenue, it may be required to curtail or cease its operations.