I-Mab presents Gibastomig Phase 1b dose escalation data

I-Mab (IMAB) announced the presentation of Phase 1b combination data for givastomig, in combination with nivolumab and mFOLFOX6, at the European Society for Medical Oncology Gastrointestinal Cancers Congress 2025 in Barcelona. Givastomig is a bispecific antibody targeting Claudin 18.2 and 4-1BB. I-Mab plans to host a virtual investor event on Tuesday, July 8th to review these data. The Phase 1b data show a confirmed objective response rate of 71% across all doses, and 83% at doses selected for the ongoing dose expansion study. Responses occurred in tumors with low levels of PD-L1 expression and/or Claudin 18.2 expression, with favorable overall tolerability. There were no Grade 3 or greater events for nausea and vomiting, and only one Grade 3 TRAE for increased liver enzymes. The data are based on the results of the dose escalation part of a Phase 1b study evaluating the givastomig combination as first line therapy in patients with Claudin 18.2-positive gastric cancers. The primary endpoint is safety. The study enrolled only patients in the U.S.