Semorinemab (, ; developmental code names MTAU-9937A, RG-6100, RO-7105705) is a monoclonal antibody against tau which was under development for the treatment of Alzheimer's disease but was discontinued. It binds to the "N"-terminus of all six isoforms of tau. The drug was ineffective in the treatment of Alzheimer's disease in two phase 2 clinical trials. Clinical development of semorinemab for Alzheimer's disease was discontinued in February 2024.