Zenapax (Daclizumab) to Treat Relapsing Remitting Multiple Sclerosis

Multiple sclerosis (MS) is considered a T cell-mediated autoimmune disease leading to central nervous system (CNS) inflammation, demyelination, axonal loss, and leads to substantial disability in young adults. Existing approved treatments include interferon beta, glatiramer acetate and mitoxantrone. These therapies are only moderately effective in reducing disease activity. The Neuroimmunology Branch (NIB) has during the last three years tested the tolerability and safety of monthly intravenously administered daclizumab (Zenapax(Registered Trademark)), a humanized monoclonal antibody against the IL-2 receptor alpha chain, in patients who receive interferon-beta, but responded incompletely to therapy with interferon-beta. Daclizumab has been well tolerated and inhibited inflammatory disease activity by almost 90%. Under an amendment of this protocol, it was demonstrated that the efficacy of daclizumab is maintained once interferon-beta therapy is discontinued. In the current trial, we will test the efficacy of daclizumab alone in relapsing-remitting MS patients. This trial is a single-centre, open-label, baseline to treatment cross-over phase II trial. Daclizumab will be administered intravenously at 1mg/kg bodyweight. Contrast-enhancing MRI lesions will serve as the primary outcome measure in this phase II trial, and a number of clinical, MRI, and immunological parameters will be measured as secondary and tertiary outcomes. Daclizumab is a promising new immunomodulatory treatment for relapsing-remitting MS.