<prompt> Monoclonal antibody used in Head and neck cancer is:-PembrolizumabTrastuzumabRituximabOcralizumab  <response>: Drug Mechanism of action Uses Pembrolizumab Monoclonal antibody against PD 1 Multiple myeloma Non small cell lung cancer Head and neck cancer Any cancer containing mismatch repair Trastuzumab Monoclonal antibody against her-2neu Breast cancer, gastroesophageal junction cancer Rituximab Monoclonal antibody against CD20 Non hodgkins lymphomaNHL, chronic lymphocytic leukemiaCLL Ocrelizumab Monoclonal antibody against CD20 Primary progressive multiple sclerosisPPMS 