Extension Study to Evaluate Safety and Efficacy of Natalizumab in Japanese Participants With Relapsing-Remitting Multiple Sclerosis

Study Overview
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Brief Summary
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The primary objective of the study is to further evaluate the long-term safety and tolerability profiles of BG00002 (natalizumab) in Japanese participants with relapsing-remitting multiple sclerosis (RRMS). The secondary objective of this study is to further evaluate the long-term efficacy profile of BG00002 in Japanese participants with RRMS.

Detailed Description
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This is a multicenter, long-term, open-label, extension study in participants who have successfully completed Study 101MS203 (NCT01440101).

Official Title
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A Long-Term, Open-Label, Multicenter, Extension Study to Evaluate Safety and Efficacy of BG00002 in Japanese Subjects With Relapsing-Remitting Multiple Sclerosis

Conditions
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Relapsing-Remitting Multiple Sclerosis, Multiple Sclerosis

Intervention / Treatment
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* Drug: natalizumab


Participation Criteria
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Eligibility Criteria
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Key Inclusion Criteria: Ability to understand the purpose and risks of the study and provide signed and dated informed consent and any authorizations required by local law. Subjects who participated in and completed all protocol-related evaluations through Week 24 of Study 101MS203 (NCT01440101). Subjects participating in study 101MS204 (NCT01416155) participated either in the open label pharmacokinetics-pharmacodynamics study or placebo-controlled study of natalizumab 300 mg q4wks (parts A and B of study 101MS203, respectively). Subjects of childbearing potential must practice effective contraception during the study and be willing and able to continue contraception for 12 weeks after their last dose of study treatment. Must be willing to remain free from concomitant immunosuppressive or immunomodulatory treatment (including interferon beta [IFNβ] and long-term systemic corticosteroids) for the duration of the study. Key Exclusion Criteria Medical History Any significant change in medical history since Study 101MS203 (NCT01440101), including laboratory tests, or current clinically important condition that in the opinion of the Investigator would have excluded the subject's participation in the previous study. The Investigator must re-review the subject's medical fitness for participation and consider diseases that would preclude treatment. Subjects from Study 101MS203 (NCT01440101) who discontinued study treatment due to an adverse event. Subjects who are determined to be persistently positive for anti-BG0002 antibodies based on prior testing. Treatment History Treatment with any of the following medications between last dose of study treatment in Study 101MS203 (NCT01440101) and the start of this study: intravenous immunoglobulin (IVIg), plasmapheresis, cytapheresis, immunosuppressant medications (e.g., mitoxantrone, azathioprine, cyclophosphamide, methotrexate, cyclosporine, FTY720), immunomodulatory medications (including IFNβ and glatiramer acetate [GA]) total lymphoid irradiation, cladribine, T-cell or T-cell receptor vaccination, any murine protein, any other therapeutic monoclonal antibody, or any 4-aminopyridine or related products. Miscellaneous For female subjects, unless postmenopausal for at least 1 year or surgically sterile (does not include tubal ligation), unwillingness to practice effective contraception, as defined by the Investigator, during the study. Women considering becoming pregnant while on study are to be excluded. Female subjects who are currently pregnant or breast feeding, including subjects whose pregnancy test is positive at Week 0. Unwillingness or inability to comply with the requirements of this protocol, including the presence of any condition (physical, mental, or social) that is likely to affect the subject's ability to comply with the study protocol. Subjects with any other condition, clinical finding, or reason that in the opinion of the Investigator and/or the Sponsor makes the subject unsuitable for enrollment into the study. NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: natalizumab<br>300 mg intravenous (IV) infusions of natalizumab every 4 weeks until product is approved in Japan or development is discontinued in Japan, whichever comes first. | Drug: natalizumab<br> <br> * Other names: BG00002;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Adverse Events (AEs), Serious AEs (SAEs), and Discontinuations Due to AEs | An AE was any untoward medical occurrence that did not necessarily have a causal relationship with this treatment. An SAE was any untoward medical occurrence that at any dose: resulted in death; in the view of the Investigators, placed the subject at immediate risk of death (a life-threatening event); however, this did not include an event that, had it occurred in a more severe form, might have caused death; required inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent or significant disability/incapacity; resulted in a congenital anomaly/birth defect; any other medically important event that, in the opinion of the Investigators, could have jeopardized the subject or may have required intervention to prevent one of the other outcomes listed in the definition above. | Day 1 through First Follow-Up (12 Weeks After Last Infusion) +/- 7 days. Approximately 62 months | 
| Number of Participants With Serum Antibodies to Natalizumab | Negative is defined as negative for antibodies at all post-baseline results. Transient positivity is defined as only 1 positive result. Persistent positivity is defined as 2 positive results separated by at least 6 to 12 weeks. | Day 1 up to approximately 50 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Adjusted Annualized Relapse Rate | Clinical relapses are defined as new or recurrent neurologic symptoms, not associated with fever or infection, lasting for at least 24 hours, and accompanied by new objective neurological findings upon examination by the neurologist. The annualized relapse rate is calculated overall as the total number of relapses experienced in the study divided by the number of days followed in the study, and the ratio multiplied by 365. Obtained from a Poisson regression model, adjusted for the baseline relapse rate from study 101MS203 (NCT01440101). | Day 1 up to approximately 50 months | 
| Mean Change From Baseline in the Assessment of Expanded Disability Status Scale (EDSS) up to Week 192 | The EDSS measures disability status on a scale ranging from 0 to 10, with higher scores indicating more disability. Scoring is based on measures of impairment in eight functional systems on examination by a neurologist. | Day 1 up to Week 192 |