Natalizumab Re-Initiation of Dosing

Phase 3

Completed

Conditions: Multiple Sclerosis, Relapsing-Remitting

Interventions: Biological: BG00002 (natalizumab)

Registration Number: NCT00306592

Lead Sponsor: Biogen

Brief Summary: 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: 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).

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 404

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

Study & Design

Study Type: INTERVENTIONAL

Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Natalizumab	BG00002 (natalizumab)	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.

Primary Outcome Measures

Name	Time	Method
Number of Participants With Treatment-Emergent Adverse Events (AEs) and Serious AEs (SAEs)	Baseline through Week 48	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.
Number of Participants With Hypersensitivity-related Adverse Events	Baseline through Week 48	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.
Number of Participants With Antibodies to Natalizumab	Baseline (Week 0), Week 4, Week 24 (test was repeated after 8 weeks if positive, to confirm persistence)	'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.