Sanofi’s SAR446523, a GPRC5D monoclonal antibody, earns orphan drug designation in the US for multiple myeloma Designation granted for IgG1-based GPRC5D monoclonal antibody for the potential treatment of patients with relapsed or refractory multiple myeloma Paris, July 30, 2025. The US Food and Drug Administration (FDA) has granted orphan drug designation to SAR446523, an IgG1-based Antibody-Dependent Cellular Cytotoxicity-enhanced (ADCC) monoclonal antibody (mAb) targeting G-protein coupled receptor family ...