A Study to Evaluate the Efficacy and Safety of Dupilumab in Adult Patients With Bullous Pemphigoid

The main purpose of this study is to investigate whether dupilumab is effective and safe for the treatment of bullous pemphigoid. Dupilumab is a type of drug called a "monoclonal antibody". An antibody is a special kind of protein that the immune (defense) system normally makes to fight bacteria and viruses. Bullous pemphigoid is an autoimmune subepidermal blistering disease, predominately affecting the elderly (typical onset after age 60). The study is looking at several other research questions, including: * Side effects that may be experienced by people taking dupilumab * How dupilumab works in the body and affects the body * How dupilumab affects quality of life * How much dupilumab is present in the blood * To see if dupilumab works to wean the patient off oral corticosteroids