TRANSTHERA-B - VOLUNTARY ANNOUNCEMENT

Approval for Conducting China Phase II Clinical Trial of TT-00973 Tablets in Combination with Firmonertinib Mesylate in the Treatment of Locally Advanced or Metastatic Non-Small Cell Lung Cancer Harboring EGFR-Sensitive Mutations

TransThera Sciences (Nanjing), Inc.

藥捷安康（南京）科技股份有限公司 (A joint stock company incorporated in the People's Republic of China with limited liability) (Stock Code: 2617)

VOLUNTARY ANNOUNCEMENT

Approval for Conducting China Phase II Clinical Trial of TT-00973 Tablets in Combination with Firmonertinib Mesylate in the Treatment of Locally Advanced or Metastatic Non-Small Cell Lung Cancer Harboring EGFR-Sensitive Mutations

This announcement is made by TransThera Sciences (Nanjing), Inc. (the "Company", together with its subsidiaries, the "Group") on a voluntary basis to inform the shareholders and potential investors of the Company about the latest business advancement of the Group.

The board of directors (the "Board") of the Company announces that the Phase II clinical trial of the Company's product, TT-00973 tablets, in combination with firmonertinib mesylate in the treatment of locally advanced or metastatic non-small cell lung cancer（ NSCLC） harboring EGFR-sensitive mutations, has been approved by the National Medical Products Administration (NMPA) on 10 July 2026.

This trial is a multi-center, open-label Phase II study to evaluate the safety and efficacy of TT-00973 tablets in combination with firmonertinib mesylate in NSCLC patients harboring EGFR-sensitive mutations.

TT-00973 is a novel dual AXL/FLT3 inhibitor independently developed by the Company. AXL kinase is a key player in survival, metastasis, and drug resistance in cancer, and aberrant activation of AXL signaling is associated with poor prognosis in many types of cancers. TT-00973 potently abrogates AXL activation in tumor cells and exhibits robust antitumor activity in preclinical models that overexpress AXL. As of 31 December 2025, the Company has completed the Phase I clinical trial, in which TT-00973 was well tolerated and clinical efficacy was observed in some patients with solid tumors.

In May 2026, the Company and Shanghai Allist Pharmaceuticals Co., Ltd. entered into a clinical collaboration and drug supply agreement to jointly conduct a Phase II study of TT-00973 tablets in

combination with firmonertinib mesylate in patients with locally advanced or metastatic non-small cell lung cancer with EGFR-sensitive mutations, and will, based on the results of this clinical trial, jointly explore collaboration opportunities for further conducting a Phase III clinical trial of the combination of TT-00973 tablets and firmonertinib mesylate.

Warning under Rule 18A.08(3) of the Listing Rules: There is no assurance that the relevant products will ultimately be successfully developed and marketed by the Company.

By order of the Board TransThera Sciences (Nanjing), Inc. 藥捷安康(南京)科技股份有限公司 Dr. Frank Wu Chairman and Chief Executive Officer

Hong Kong, 10 July 2026