Alternative Treatment Paradigm for Natalizumab Trial

This is a phase IIb, multicenter, double-blinded randomized trial that will determine the effects of two GA treatment paradigms to prevent re-occurrence of disease activity and immunological rebound after withdrawal from natalizumab therapy. Importantly, the results of this trial may apply to other immunoactive agents. A total of 200 patients with relapsing forms of multiple sclerosis (MS) will be recruited at 20 study sites in the United States and Europe. Natalizumab at a dose of 300 mg intravenous (i.v.) infusion each month will be given as standard of care for at least 9 months prior to patient being enrolled in the study. One day after the last infusion of natalizumab the patient will start conversion paradigms to Glatiramer Acetate (GA). GA will be administered daily at a subcutaneous (s.c.) dose of 20 mg. On day 1, 2 months after the patient has been on GA therapy, patient will be randomized to be treated with methylprednisolone or methylprednisolone placebo at an oral dose of 192 mg/day po for 5 consecutive days per month for the duration of the study. Both Natalizumab and Glatiramer Acetate (GA) have been approved by the FDA to treat relapsing remitting multiple sclerosis. Natalizumab will not be given as a study medication. Part of the inclusion criteria is that patients are already receiving Natalizumab as standard of care. Natalizumab until randomization will be provided by the patients' medical insurance. Glatiramer acetate (GA) from randomization till the end of the study (for 12 months) will be provided by the patients' medical insurance. Teva Pharmaceuticals is the manufacturer of methylprednisolone and methylprednisolone placebo 24-mg tablets, which will look identical. Treatment Arms During a 1 month screening period (month -1), inclusion and exclusion criteria will be verified, and subjects will be enrolled in the GA only portion following registration with the web-based data entry system and at month 3, they will be randomly assigned to treatment that will be stratified according to study site in varying block sizes One day after the last natalizumab infusion (month 0), 200 Patients on natalizumab therapy will be started on GA. On day 1 of month 3, subjects will be randomized 1:1 to receive either: 1. Methylprednisolone placebo ("GA \& PL") or 2. Methylprednisolone ("GA \& MP") in addition to GA therapy. Randomization to the two treatment arms will occur via a random number generator by a centralized data entry system that checks eligibility prior to initiating randomization to prevent inappropriate inclusions. Study Endpoints: 1. The primary endpoint will be the annualized relapse rate. 2. A key secondary endpoint is the percentage of relapse-free patients at 12 months. 3. Other secondary outcomes are the rate of early relapse rebound (assessed in all 200 patients prior to randomization), number of new GD+ lesions on MRI over the 12 months treatment period, defined as the period following the first infusion (month 0) to 6 months and 12 months after randomization, annualized relapse rate, and progression of neurological as assessed by changes in EDSS. 4. Other MRI outcomes will include the cumulative combined unique activity (CUA) (new or enlarging T2 lesions or enhancing lesions). 5. Another secondary endpoint is the percentage of patients who appear to be free of disease activity as measured by clinical relapses, disability progression measured by the Expanded Disability Status Scale EDSS), and the cumulative combined unique activity (CUA) (new or enlarging T2 lesions or enhancing lesions) on MRI at 12 months.