Transcenta Received Approvals from China CDE and South Korea MFDS to Initiate TranStar 301 Global Phase III Pivotal Trial of Osemitamab (TST001)

SUZHOU,China,July 7,2023 -- Transcenta Holding Limited ("Transcenta") (HKEX: 06628),a clinical stage biopharmaceutical company with fully-integrated capabilities in discovery,research,development and manufacturing of antibody-based therapeutics,announces that it has received approvals from China CDE (Center for Drug Evaluation) and South Korea MFDS (Ministry of Food and Drug Safety) to initiate TranStar 301 global Phase III pivotal trial of Osemitamab (TST001) in combination with Nivolumab and chemotherapy for the first-line treatment of patients with HER2 negative,CLDN18.2 expressing locally advanced or metastatic gastric or gastroesophageal (G/GEJ) adenocarcinoma. In addition,we are in the process of EU and FDA regulatory interaction.

Gastric cancer (GC) is the 4th leading cause of cancer death worldwide,accounting for about 7.7% of all cancer related mortality. The five year survival rate for gastric cancer is still around 30%. Nivolumab,an anti-PD-1 antibody,has been approved globally for the first line treatment of patients with advanced or metastatic HER2-negative G/GEJ cancer.

Osemitamab (TST001) is a second generation humanized CLDN18.2 targeting antibody with enhanced ADCC. It has shown anti-tumor activities in preclinical models with a broad range of CLDN18.2 expression. Recently,the Company presented efficacy data of Osemitamab (TST001) in combination with CAPOX as the first-line treatment of G/GEJ cancer at 2023 ASCO annual meeting and 2023 ESMO GI. Among 64 patients with CLDN18.2 positive (defined as: IHC membrane staining ≥10% tumor cells with ≥1+ intensity per LDT assay,selecting approximately 55% of the screened patients) were treated,49 at the dose of 6mg/kg. The data showed that the estimated median progression-free survival was 9.5 months from all dose groups,consistent across all CLDN18.2 expression levels,with a median duration of response of 9.9 months.

Preclinical studies have demonstrated synergistic anti-tumor activities between Osemitamab (TST001) and anti-PD-1 antibodies in CLDN18.2 expressing tumor models. Recently Transcenta has reported that 82 patients had been enrolled in TranStar 102 to assess the safety and efficacy of Osemitamab (TST001) in combination with Nivolumab and CAPOX. So far,the combination is well tolerated.

TranStar 301 is a global randomized,double-blind,placebo-controlled Phase III trial designed to evaluate Osemitamab (TST001) in combination with Nivolumab plus chemotherapy as the first-line treatment for patients with locally advanced or metastatic HER2 negative,CLDN18.2 expressing G/GEJ adenocarcinoma.

"We are actively progressing our plans to develop Osemitamab (TST001) in combination with Nivolumab and chemotherapy as first-line treatment for CLDN18.2 expressing G/GEJ adenocarcinomas in a large multinational Phase III clinical trial. CDE and MFDS approvals are exciting milestones,with several others coming soon. We are looking forward to sharing more information as it becomes available." said Dr. Caroline Germa,Transcenta's Executive Vice President,Global Medicine Development and Chief Medical Officer.

References:

[1] 2023 ESMO Poster: https://www.transcenta.com/Scientific_Publications/id-125.html

[2] 2023 ASCO Poster: https://www.transcenta.com/Scientific_Publications/id-124.html

About Osemitamab (TST001)

Osemitamab (TST001) is a high affinity humanized anti- CLDN18.2 monoclonal antibody with enhanced antibody-dependent cellular cytotoxicity ("ADCC"). It has shown potent anti-tumor activities in tumor xenograft models. Osemitamab (TST001) is the second most advanced CLDN18.2 targeting antibody being developed globally. Osemitamab (TST001) was generated using Transcenta's Immune Tolerance Breaking Technology (IMTB) platform. Osemitamab (TST001) kills CLDN18.2 expressing tumor cells by mechanisms of ADCC. Leveraging advanced bioprocessing technology,the fucose content of Osemitamab (TST001) was significantly reduced during the production,which further enhanced NK cells mediated ADCC activity of Osemitamab (TST001). Clinical trials for Osemitamab (TST001) are ongoing in the U.S. and China (NCT05190575,NCT04396821,NCT04495296,NCT05608785 / CTR20201281). Osemitamab (TST001) was granted Orphan Drug Designation in the U.S. by FDA for the treatment of patients with gastric or gastroesophageal junction (G/GEJ) and pancreatic cancer.

About Transcenta Holding Limited

Transcenta (HKEX: 06628) is a clinical stage biopharmaceutical company with fully integrated capabilities in antibody-based biotherapeutics discovery,development and manufacturing.

Transcenta has established global footprint,with Headquarters and Discovery,Clinical and Translational Research Center in Suzhou,Process and Product Development Center and Manufacturing Facility in Hangzhou,and Clinical Development Centers in Princeton,US and in Beijing,Shanghai and Guangzhou of China,and Business Development Center in Boston and Los Angeles,US. Transcenta has also initiated the construction of the Group Headquarters and the second high-end biopharmaceutical facility with HiCB as its core technology in Suzhou Industrial Park. Transcenta is developing 13 therapeutic antibody molecules for oncology and selected non-oncology indications including bone and kidney disorders.

For more information,please visit www.transcenta.com and https://www.linkedin.com/company/transcenta.

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