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, and Agilent Technologies, announce a collaboration to develop a Claudin18.2 (CLDN18.2) companion diagnostic to support TranStar301 global Phase III pivotal trial of Osemitamab (TST001) in combination with Nivolumab and chemotherapy as first-line treatment in patients with CLDN18.2 expressing locally advanced or metastatic gastric or gastroesophageal (G/GEJ) adenocarcinoma.

Transcenta has developed a mouse anti-CLDN18.2 monoclonal antibody, clone 14G11 which specifically binds to CLDN18.2 but not CLDN18.1. This antibody, generated against a linear epitope located on the extracellular domain of loop 1, has a binding site that overlaps with the binding site of therapeutic antibody Osemitamab (TST001).

Transcenta has been collaborating with Agilent, a world leader in CDx development, to further develop this antibody for use in a companion diagnostic assay. Agilent is developing Claudin18.2 IHC 14G11 pharmDx, an immunohistochemistry (IHC) assay for the detection of CLDN18.2 protein in gastric and gastroesophageal junction (GEJ) adenocarcinoma with the potential for other indications. Agilent and Transcenta presented the early results of the Claudin18.2 IHC 14G11 pharmDx assay at AACR Annual Meeting. Claudin18.2 IHC 14G11 pharmDx for Investigational Use Only/for Performance Evaluation Only will be used for patient selection in the phase III trial of gastric/GEJ adenocarcinoma where applicable ethics committee and regulatory approvals have been granted.

"Agilent's expertise in the development of companion diagnostics is impressive, as is their strong track record of developing companion diagnostics across the precision oncology sector," said Dr. Caroline Germa, Transcenta's Executive Vice President, Global Medicine Development and Chief Medical Officer. "We are excited about the collaboration and look forward to working together to pave the way for enhanced patient health outcomes."

"We are excited to be working with Transcenta on the development of the Claudin18.2 IHC 14G11 pharmDx companion diagnostic assay," said Dr. Paul Beresford, VP/GM of CDx, Agilent. "This partnership with Transcenta will further pave the way for enhanced precision medicine products for those with gastric and gastroesophageal junction adenocarcinoma, and continue transforming diagnostics, treatments, and patient health outcomes."