Safety and Effectiveness of h5G1.1-mAb for Dermatomyositis

Patients age greater than or equal to 18 years. Patients with a diagnosis of definite or probable dermatomyositis by criteria of Bohan et. al., with either active rash typical of dermatomyositis, history of rash typical of dermatomyositis, or Gottron's papules. Patients with a manual muscle testing score less than or equal to 136/170. Patients with a disease duration greater than or equal to 6 months. Patients with persistent disease (defined as active rash plus CK greater than or equal to 2 times ULN), or rapidly progressive disease, or response to steroids with inability to taper dose, or unacceptable side effects of steroids. Patients may be on stable (times 28 days prior to Visit 2) dose of MTX or AZA. No other immunosuppressive agents times 84 days prior to first dose. Patients on stable oral steroid use for 28 days prior to Visit 2. Patients with adequate hematologic function, defined as hemoglobin greater than or equal to 8.5 g/dl, WBC greater than or equal to 3,000 mm(3), neutrophils greater than or equal to 1,200 mm(3), platelets greater than or equal to 100,000 mm(3). Patients must be willing and able to give informed consent. Women must be post-menopausal, surgically sterile or practicing a medically approved method of contraception. Patients with liver disease will be excluded. Patients with history of alcohol or drug abuse within two years of screening, or a history of positive Hepatitis B or Hepatitis C serology, unless vaccinated will be excluded. Patients with renal insufficiency, defined as creatinine greater than or equal to 2.0 mg/dl will be excluded. Patients with history of malignancy, except basal cell carcinoma and remote (greater than or equal to 5 years) malignancies in complete remission will be excluded. Patients with history of poorly controlled diabetes will be excluded. Patients with presence or suspicion of active infection, recent serious infection, or chronic/recurrent viral or bacterial infection will be excluded. Patients with throat culture positive for pathogenic Neisseria species (meningitidis or gonorrhoeae) will be exluded. Subjects with a positive culture may be treated with appropriate antibiotic therapy and retested. Patients with joint disease or replacement that would interfere with patient's ability to perform muscle testing will be excluded. Patients with any clinically significant medical condition that is likely to interfere with the participation in the study or the evaluation of the study medication's safety profile will be excluded. No patients with known or suspected hereditary complement deficiency will be excluded. Patients with history of allergic reaction to murine proteins will be excluded. Patients participating in any other investigational drug trial, or exposure to other investigational agent or device within thirty days prior to screening will be excluded. Pregnant or breastfeeding patients will be excluded. Women intending to conceive during the course of the study, including follow-up period will be excluded. Patients with history of HIV, Lyme disease, or other environmentally induced myositis will be excluded.