margetuximab + retifanlimab

Margetuximab + retifanlimab is an experimental **combination therapy** of two monoclonal antibodies. **Margetuximab** is an Fc-engineered, anti-HER2 monoclonal antibody designed to enhance immune-mediated killing of HER2-expressing cancer cells, and **retifanlimab** is a humanized IgG4 anti-PD-1 monoclonal antibody that blocks the PD-1/PD-L1/PD-L2 interaction to release inhibition of T-cell-mediated immune responses. This chemotherapy-free regimen was studied as a first-line treatment specifically for patients with HER2-positive and PD-L1-positive unresectable or metastatic gastroesophageal adenocarcinoma (GEA)[1][2][3]. Developed to improve upon the standard trastuzumab-based therapy, this combination was investigated in the MAHOGANY study. The study was discontinued for regulatory reasons, not due to safety or efficacy concerns[1]. Both drugs are investigational for this indication.