Zhitong Finance App News, Chuangsheng Group-B (06628) issued an announcement to cooperate with Agilent Technologies to develop Claudin18.2 (CLDN 18.2) as a diagnostic reagent to support Osemitamab (TST001) combined with navulimab and chemotherapy as first-line treatment of locally advanced or metastatic gastric or gastroesophageal junction (G/GEJ) adenocarcinoma expressed by CLDN18.2 as a first-line treatment for patients with locally advanced or metastatic gastric or gastroesophageal junction (G/GEJ) adenocarcinoma expressed by CLDN18.2.

An anti-CLDN 18.2 mouse monoclonal antibody developed by the company: 14G11 clone, can specifically bind CLDN 18.2 without binding to CLDN 18.1. The antibody was generated against a linear epitope located outside the cell domain of loop1, and its binding site overlaps the binding site of the therapeutic antibody Osemitamab (TST001).

The company works closely with Agilent, a global leader in companion diagnostic development, to jointly advance the further development of this antibody and its application in companion diagnostic reagents. Agilent is developing an immunohistochemistry (IHC) reagent CLDN18.2 IHC 14G11 PharmDx to detect CLDN18.2 protein in gastric or gastroesophageal junction (G/GEJ) adenocarcinoma, and possibly for other indications. Agilent and Corp. presented early findings on the CLDN18.2 IHC 14G11 PharmDx reagent at the AACR annual meeting. CLDN18.2 IHC 14G11 PharmDx (for research use/performance evaluation only) will be used to screen patients for gastric or gastroesophageal junction (G/GEJ) adenocarcinoma phase III trials and has obtained appropriate ethics committee and regulatory approval.

“Given Agilent's extensive experience in developing concomitant diagnoses in the field of precision oncology in the past, its expertise in companion diagnostic development is impressive,” said Dr. Caroline Germa, the company's executive vice president of global drug development and chief medical officer. “We are excited to reach this partnership and look forward to working together to improve patient outcomes and promote patient welfare.”

“We are very happy to work with Chuangsheng Group to develop CLDN18.2 IHC 14G11 PharmDx companion diagnostic reagent,” said Dr. Paul Beresford, President and General Manager of Agilent's Accompanying Diagnosis Division. “This collaboration with Chuangsheng Group will provide more accurate medical products for patients with gastric or gastroesophageal junction (G/GEJ) adenocarcinoma, thereby improving diagnosis, treatment, and patient health.”

Osemitamab (TST001) is a high-affinity humanized monoclonal antibody against CLDN18.2. It has enhanced antibody-dependent cytotoxicity (ADCC) and has shown strong anti-tumor activity in tumor xenograft tests. Osemitamab (TST001) is the second most advanced CLDN18.2-targeted antibody drug developed globally by the company through its Immune Tolerance Breakthrough (IMTB) technology platform. Osemitamab (TST001) kills CLDN18.2-expressing tumor cells via ADCC mechanism. Using advanced bioprocessing technology, the fucose content of Osemitamab (TST001) was greatly reduced during production, further enhancing the NK cell-mediated ADCC activity of Osemitamab (TST001). Both China and the US have been conducting clinical trials of Osemitamab (TST001) (NCT05190575, NCT04396821, NCT04495296, NCT05608785/CTR20201281). The US Food and Drug Administration (FDA) has granted Osemitamab (TST001) an orphan drug qualification to treat patients with gastric cancer or gastroesophageal junction (G/GEJ) adenocarcinoma and pancreatic cancer.