Natalizumab Re-Initiation of Dosing

Study Overview
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Brief Summary
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The primary objectives of this study are to further evaluate the safety of natalizumab (Tysabri®) monotherapy by evaluating the risk of hypersensitivity and immunogenicity following re-exposure to natalizumab, and to confirm the safety of switching to natalizumab from interferon beta (IFN-β), glatiramer acetate (GA), or other multiple sclerosis (MS) therapies.

Detailed Description
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Study 101-MS-322 (NCT00306592) is conducted to evaluate the safety of natalizumab monotherapy following re-exposure to natalizumab of former clinical trial participants in Studies C-1801 (NCT00027300), C-1802 (NCT00030966), and C-1803 (NCT00097760). This study includes participants in North America. In parallel with the conduct of this study, a similar study, 101-MS-321 (NCT00297232) is initiated for participants in Europe and the rest of the world. The primary purpose and primary outcome for both studies are identical, therefore, the combined Week 48 data from both studies are presented. In addition, after 48 weeks, participants from 101-MS-322 (NCT00306592) can enter study 101-MS-321 (NCT 00297232), which is considered the Long-Term Treatment Period of 101-MS-322 (NCT00306592).

Official Title
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An Open-Label, Multicenter, Extension Study to Evaluate the Safety and Tolerability of Natalizumab Following Re-Initiation of Dosing in Multiple Sclerosis Subjects Who Have Completed Study C-1801, C-1802, or C-1803 and a Dosing Suspension Safety Evaluation

Conditions
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Multiple Sclerosis, Relapsing-Remitting

Intervention / Treatment
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* Biological: BG00002 (natalizumab)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: MS subjects who completed Study C-1801 (NCT00027300), C-1802 (NCT00030966), or C-1803 (NCT00097760) and completed a Dosing Suspension Safety Evaluation (neurological examination and magnetic resonance imaging [MRI] scan) Considered by the investigator to be free of signs and symptoms suggestive of progressive multifocal leukoencephalopathy (PML) based on medical history, physical examination, or laboratory testing (results from the Dosing Suspension Safety Evaluation from Study C-1808 [NCT000276172] may be used) Other protocol-defined inclusion criteria may apply Exclusion Criteria: Considered by the investigator to be immunocompromised, based on medical history, physical examination, or laboratory testing (results from the Dosing Suspension Safety Evaluation from Study C-1808 may be used), or due to prior immunosuppressive treatment History of persistent anti-natalizumab antibodies, based upon testing from prior natalizumab studies Other protocol-defined exclusion criteria may apply

Ages Eligible for Study
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Minimum Age: 18 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>All study participants in 101-MS-322 (NCT00306592) and 101-MS-321 (NCT00297232) received open label 300 mg intravenous (IV) natalizumab 60-minute infusion once every 4 weeks (28 days ±7 days) for up to 48 weeks. After 48 weeks, participants from 101-MS-322 (NCT00306592) entering study 101-MS-321 (NCT 00297232; considered the Long-Term Treatment Period of 101-MS-322) were continued on treatment from Week 52 through Week 480. | Biological: BG00002 (natalizumab)<br> <br> * Other names: Tysabri;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Treatment-Emergent Adverse Events (AEs) and Serious AEs (SAEs) | AEs: any sign, symptom, or diagnosis/disease that is unfavorable or unintended, that is new, or if pre-existing, worsens in participants administered a pharmaceutical product and that does not necessarily have a causal relationship with this treatment. SAEs: an event that results in death; an event that, in the view of the investigator, places the participant at immediate risk of death (a life-threatening event); an outcome that results in a congenital anomaly/birth defect diagnosed in a child of a participant; an event that requires or prolongs inpatient hospitalization; an event that results in persistent or significant disability/incapacity. Any other medically important event that, in the opinion of the investigator, may jeopardize the participant or may require intervention to prevent one of the other outcomes listed in the definition above. Treatment-emergent AEs: events in participants who had received at least 1 dose of study drug, regardless of relationship to study drug. | Baseline through Week 48 | 
| Number of Participants With Hypersensitivity-related Adverse Events | For purposes of this analysis, the terms 'hypersensitivity' and 'drug hypersensitivity' were categorized by their temporal relationship to study drug infusion (within 2 hours of the start of the infusion), and were considered equivalent. Hypersensitivity reactions are defined as infusion reactions with the following preferred terms: hypersensitivity not otherwise specified (NOS), anaphylactic reaction, anaphylactoid reaction, dermatitis allergic, drug hypersensitivity, urticaria NOS, vasoconstriction, urticaria generalised, hypersensitivity, urticaria. | Baseline through Week 48 | 
| Number of Participants With Antibodies to Natalizumab | 'Positive with unknown persistence' is defined as a positive result (≥0.5 micrograms/mL) at one timepoint only with no confirmatory re-test available at least 42 days later. 'Transient positive' is defined as a positive at one timepoint but negative upon re-test at least 42 days later. 'Persistent positive' is defined as positive at 2 or more timepoints separated by at least 42 days. The threshold for classifying a sample as 'antibody positive' was set at the lowest level of reactivity that had a measurable impact on drug serum concentrations. | Baseline (Week 0), Week 4, Week 24 (test was repeated after 8 weeks if positive, to confirm persistence) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Multiple Sclerosis, MS