The purpose of the study is to find out if there are any assessments that might predict
whether or not patients receiving Tysabri will remain free of disease (that is, without
relapses, worsened disability, and/or lesions on brain magnetic imaging [MRI] scans) and how
effective Tysabri is at keeping patients who are in the early stages of RRMS free of
Ability to understand the purpose and risks of the study and provide signed and dated informed consent and authorization to use protected health information (PHI) in accordance with national and local patient privacy regulations.
Documented diagnosis of Relapsing Multiple Sclerosis (McDonald 2010 Criteria [Polman et al., 2011]).
<3 year disease duration.
Must have an EDSS score from 0 to 4.0, inclusive.
Anti-JCV antibody negative test at Screening Visit
Must satisfy the approved therapeutic indications for Tysabri.
Must be treatment-naïve to disease-modifying therapy (DMT) or have been treated with a single DMT (including Avonex, Betaseron, Rebif, Copaxone, Extavia, or Gilenya) for ≤12 months total prior to date of informed consent.
Decision to treat with Tysabri must precede enrollment.
Any prior treatment with Tysabri.
Anti-JCV antibody positive at any timepoint prior to the Screening Visit.
Contraindications to treatment with Tysabri as described in the US Prescribing Information.
History of PML or other opportunistic infections, or an increased risk for such infections.
History of diagnosis of Primary Progressive Multiple Sclerosis [PPMS] and/or Secondary Progressive Multiple Sclerosis [SPMS].
Receiving immunomodulatory or immunosuppressive therapy.
Prior history of immunosuppressive use (mitoxantrone, azathioprine, methotrexate, cyclophosphamide, mycophenolate, cladribine, rituximab).
Immunocompromised at the time of enrollment.
Known active malignancies (subjects with cutaneous basal cell carcinoma that has been completely excised prior to study entry remain eligible).
Women breastfeeding, pregnant, or planning to become pregnant; women who are not post-menopausal or surgically sterile who are unwilling to practice contraception.