Transcenta Holding Limited announced updated efficacy analysis of Cohort G by CLDN18.2 and PD-L1 expression from the phase I/II Transtar102 trial of osemitamab plus nivolumab and CAPOX in first-line Gastric/Gastroesophageal Junction (G/GEJ) cancer. The new findings were showcased in a poster presentation (Abstract #299P) at the ESMO Asia Congress 2025 in Singapore. This new analysis reinforces the encouraging clinical benefit of the osemitamab triple combination regimen in the ongoing study.
In the 26 patients with CLDN18.2 expression 40%, 2+ and known PD-L1 CPS, the median PFS reached 16.6 months, with an ORR of 68% and a median DoR of 18 months at a 25.8-month median follow-up. Notably, better PFS outcomes were observed in patients with higher CLDN18.2 expression compared to lower CLDN18.2expressors in both PD-L1 CPS. Osemitamab is the second CLDN18.2 targeting antibody being developed globally.
Osemitamab was generated using Transcenta's Immune Tolerance Breaking Technology (IMTB) platform. Osemitamab kills CLDN18.2 expressing tumor cells by mechanisms of ADCC. Leveraging advanced bioprocessing technology, the fucose content of osemitamab was significantly reduced during the production, which further enhanced NK cells mediated ADCC activity of osemitamab.
Osemitamab has been 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.
