Evaluating Sirolimus to Treat Autoimmune Blistering Dermatosis Pemphigus

The purpose of this study is to explore a new medication for the skin disease termed pemphigus. Our specific aim is to determine whether the use of sirolimus will allow for a decrease in the dosage or possibly eliminate the need for corticosteroids, which so far is the only type of drug that can control this disease. Pemphigus is an autoimmune disease characterized by blistering, caused by autoantibodies against certain cells in the skin. This disease most commonly occurs in individuals ages 50 and older, and it presents as painful shallow erosions and/or blisters in the mouth and/or skin. Pemphigus is very painful and uncomfortable, associated with impaired quality of life and significant morbidity. Severe or untreated cases of pemphigus can become fatal if the involved surface area becomes large enough to cause dehydration and/or infection. The first line of therapy, and the standard of care, for pemphigus remain to be systemic corticosteroids. However, corticosteroids have many known side effects, especially when used for a long time. Many cases of pemphigus are insufficiently controlled with corticosteroids alone and require the addition of other immunosuppressive agents, such as azathioprine, cyclophosphamide, mycophenolate mofetil, or a variety of other therapies used off-label. All of these treatments are not always successful and have undesirable side effects, including increased risk of malignancy and infections. Although these treatments can offer some relief from the disease, they are also often the cause of many side effects. Sirolimus (formerly known as rapamycin) is a drug commonly used after renal transplants to prevent organ rejection. In this study, pemphigus subjects with active disease will begin taking sirolimus in conjunction with corticosteroids, using a similar regimen used for organ transplantation to treat pemphigus. While increasing sirolimus and decreasing the corticosteroids, subjects will be monitored over a 12 month period to evaluate their disease response. The purpose of this study is to observe data trends. Our specific aim is to determine whether the use of sirolimus will allow for a decrease in the dosage of the corticosteroid prednisone, which so far is the only type of drugs that can control these diseases, without making the pemphigus worse.