Safety and Efficacy Study of Eculizumab in Patients With Refractory Generalized Myasthenia Gravis

A Randomized, Double-Blind, Placebo-Controlled, Cross-Over, Multi-Center Study of Eculizumab in Patients With Generalized Myasthenia Gravis (gMG) Who Have Moderate to Severe Muscle Weakness Despite Treatment With Immunosuppressants

The purpose of this study is to determine whether eculizumab is safe and effective in the treatment of patients with generalized myasthenia gravis despite treatment with various immunosuppressants, such as prednisone, methotrexate, Cellcept, cyclosporine, and cyclophosphamide, that are currently available.

Inclusion Criteria:

• Generalized MG
• MGFA Clinical Classification Class II, III or IVa.
• QMG total score ≥12
• Minimum score of two (2) in four (4) or more test items in the QMG
• Able to give informed consent.
• Have failed at least two immunosuppressants after one year of treatment
• A positive serologic test for binding anti-acetylcholine receptor Abs at Screening and one of the following a) history of abnormal neuromuscular transmission test demonstrated by single-fiber electromyography or repetitive nerve stimulation, or b) history of positive anticholinesterase test, eg, edrophonium chloride test, or c) patient has demonstrated improvement in MG signs on acetylcholinesterase inhibitors as assessed by treating physician.

Exclusion Criteria:

• History of thymoma or other neoplasms of the thymus.
• History of thymectomy within 12 months prior to screening.
• Pregnancy or lactation
• Current or chronic use of plasmapheresis/plasma exchange
• IVIG treatment within 8 weeks prior to screening.
• Use of etanercept within 2 months prior to screening.
• Use of rituximab (RITUXAN®) within 6 months prior to screening.
• MGFA Class I, IVb, and V
• Crisis or impending crisis