Study of Tcelna (Imilecleucel-T) in Secondary Progressive Multiple Sclerosis

Inclusion Criteria: * Diagnosed with MS as defined by the modified McDonald criteria * SPMS defined as relapsing-remitting disease with recent progression in MS-related neurological deficits * EDSS score 3.0 - 6.0, inclusively * Presence of myelin reactive T-cells Exclusion Criteria: * Diagnosed with primary progressive MS * Treatment with beta-interferon, glatiramer acetate or dimethyl fumarate 30 days prior to screening * Treatment with ACTH, any over-the-counter or prescription corticosteroids 60 days prior to screening * Treatment with IVIG, plasmapheresis or cytopheresis 90 days prior to screening * Treatment with mitoxantrone, teriflunomide, fingolimod, natalizumab, azathioprine, cyclosporine, methotrexate or mycophenolate mofetil 1 year prior to baseline * Any prior treatment with cladribine, cyclophosphamide, total lymphoid irradiation, T cell or T cell receptor products, or any therapeutic monoclonal antibody, except natalizumab * Previous treatment with any other MS investigational drug 1 year prior to screening * All non-MS investigational drugs must have a minimum washout of 30 days prior to screening or 5 half-lives, whatever is the longest period of time. * HIV or hepatitis infection * History of cancer * Any other significant medical condition that, in the opinion of the investigator, could cause CNS tissue damage or limit its repair.