GMA-161 / MacroGenics, Sanofi - LARVOL DELTA

Blocking FcγRIII with anti-CD16 mab (3G8 and GMA161) increases platelets in immune thrombocytopenia: Two pilot studies (ASH 2025) - "All patients hadlongstanding, severe ITP and had failed multiple prior treatments: steroids, splenectomy, vincristine,immunosuppressives, and, for the 2nd study, rituximab. Targeting FcγRIII with monoclonal antibodies produced rapid platelet increases,sometimes substantial, in most heavily-pretreated, refractory ITP patients in the pre-TPO era. The failureof IVIG and anti-FcγRIII responses to correlate both validates FcγRIIIa as a mechanistic driver of plateletclearance and that it is not the primary FcγR targeted by IVIG. The failure of correlation of IVIG and 3G8response implies that IVIG's platelet raising mechanism cannot be primarily attributed to FcγRIIIblockade."

Clinical • Hematological Disorders • Immune Thrombocytopenic Purpura • Leukopenia • Thrombocytopenia • Thrombocytopenic Purpura • ELANE • FCGR3A • RHOD