A Study Utilising Data From European Union (EU) National Multiple Sclerosis (MS) Registries to Assess the Incidence of Anti-Natalizumab Antibody Among Participants Who Receive Subcutaneous Administration of Natalizumab for Treatment of Relapsing-remitting Multiple Sclerosis (RRMS)

Study Overview
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Brief Summary
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The primary objective of this study is to estimate the incidence of Anti-Natalizumab Antibodies (ANAs) in the cohort of natalizumab-naïve and other MS monoclonal antibody (mAb)-naive participants who start receiving natalizumab subcutaneous (SC) injections. The secondary objectives of this study are to estimate the proportion of participants detected with ANAs when switched from natalizumab intravenous (IV) to natalizumab SC (natalizumab-experienced cohort); to evaluate serious adverse events (SAEs), including injection reactions and hypersensitivity reactions, by ANA status and to assess the proportion of participants who had MS relapse, by ANA status.

Detailed Description
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The study will collect data prospectively and retrospectively.

Official Title
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An Observational Study Utilising Data From EU National MS Registries to Estimate the Incidence of Anti-Natalizumab Antibody Among Patients Who Receive Subcutaneous Administration of Natalizumab for Treatment of RRMS

Conditions
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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: Participants who are natalizumab-naïve and other MS mAb-naive and who start on natalizumab SC. Participants who have previously received natalizumab IV and switch from natalizumab IV to SC administration. Key Exclusion Criteria : For the natalizumab-naive and other MS mAb-naive cohort, participants who previously received natalizumab or other MS mAbs will be excluded. For the natalizumab-experienced cohort, participants who are naive to natalizumab will be excluded. NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 64 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Cohort 1: Naive Participants<br>Per standard of care, participants with MS enrolled in selected MS registries, who are natalizumab-naïve and other MS mAb-therapy-naive will receive natalizumab 300 mg, SC injection according to decision of the treating physician. | Drug: Natalizumab<br>* Administered as specified in the treatment arm.<br>* Other names: Tysabri;|
| Cohort 2: Natalizumab Experienced<br>Per standard of care, participants with MS enrolled in selected MS registries, who have previously received natalizumab IV will be switched from natalizumab IV to SC administration to receive natalizumab 300 mg, SC injection according to decision of the treating physician. | Drug: Natalizumab<br>* Administered as specified in the treatment arm.<br>* Other names: Tysabri;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Participants in Natalizumab-Naive and Other MS mAb-Naive Cohort who Start Taking Natalizumab Injections and Develop Anti-Natalizumab Antibodies (ANAs) |  | Up to 1.75 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Participants in Natalizumab-Experienced Cohort who Switched From Natalizumab IV Infusion to SC Injection and Develop Anti-Natalizumab Antibodies (ANAs) |  | Up to 1.75 years | 
| Percentage of Participants With SAEs by Positive (Transient or Persistent) or Negative ANA Status | SAE is any untoward medical occurrence that results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in permanent or significant damage to health or limitation of capabilities or is manifested as a congenital anomaly or birth defect in offspring, irrespective of the administered dose of the medicinal product. | Up to 1.75 years | 
| Percentage of Participants With MS Relapses by Positive (Transient or Persistent) or Negative ANA Status |  | Up to 1.75 years |