Exploratory Study of the Safety, Tolerability and Efficacy of Multiple Regimens of Natalizumab in Adult Participants With Relapsing Multiple Sclerosis (MS)
Condition: Relapsing-Remitting Multiple Sclerosis
MeSH terms: Multiple Sclerosis; Multiple Sclerosis, Relapsing-Remitting; Sclerosis
Intervention: natalizumab IV; natalizumab SC; IV Placebo; SC Placebo
Intervention description: natalizumab for IV Infusion; natalizumab for Subcutaneous Injection; Intravenous placebo to natalizumab; Subcutaneous placebo to natalizumab
Intervention MeSH terms: Natalizumab
Phase: Phase 2
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Enrollment: 290.0
Sex: All
Minimum age: 18 Years
Maximum age: 55 Years
Healthy volunteers: No

Summary:

      The primary objective of this study is to explore the effects of multiple regimens of
      natalizumab on disease activity and safety in participants with relapsing-remitting Multiple
      Sclerosis (RRMS).
    

Eligibility criteria:

        Key Inclusion Criteria:

          -  Ability to provide written informed consent

          -  Subjects of childbearing potential must practice effective contraception during the
             study

          -  A documented diagnosis of Relapsing Remitting Multiple Sclerosis (RRMS)

          -  Free of MS relapse for 12 months prior to randomization

          -  Treatment with natalizumab for a minimum of 12 months immediately prior to
             randomization.

          -  In the 12 months prior to commencing natalizumab, subject must have experienced a
             minimal level of disease activity as defined by 2 or more documented clinical relapses
             OR 1 relapse and documented MRI activity, defined by the presence of at least 1 Gd
             enhancing lesion on MRI, unrelated to the relapse.

        Key Exclusion Criteria:

          -  Known history of Human Immunodeficiency Virus (HIV), hepatitis C and/or hepatitis B
             virus

          -  Positive for anti-natalizumab antibodies at screening

          -  MRI positive for Gd-enhancing lesions at study entry

          -  Subjects for whom MRI is contraindicated

          -  History of any clinically significant cardiac, endocrinologic, hematologic, hepatic,
             immunologic, metabolic (including diabetes), urologic, pulmonary, neurologic (except
             for RRMS), dermatologic, psychiatric, renal, or other major disease

          -  History of malignant disease, including solid tumors and hematologic malignancies
             (with the exception of cured basal cell and squamous cell carcinomas of the skin)

          -  History of transplantation or any anti-rejection therapy

          -  History of severe allergic or anaphylactic reactions or known hypersensitivity to any
             drug

          -  A clinically significant infectious illness within 30 days prior to screening or
             progressive multifocal leukoencephalopathy (PML) or other opportunistic infections at
             any time

          -  Signs or symptoms suggestive of any serious infection, based on medical history,
             physical examination or laboratory testing

        NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.