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Published on: February 19, 2021
Long-term effects of natalizumab on MRI activity and clinical outcomes in Japanese patients with relapsing-remitting
Takahiko Saida1,2, Qi Hao3, Michihiro Kanda4
1Kansai Multiple Sclerosis Centre, Irino Clinic Inc, TCA Building 4F, 2-3-19 Motomachi, Naniwa-ku, Osaka-shi, Osaka, Japan. msnet@bg.wakwak.com.
Background:
Relapsing-remitting multiple sclerosis (RRMS) is the most common phenotype of multiple sclerosis (MS), and its active stage is characterized by active T2 lesions with or without gadolinium (Gd) enhancement on magnetic resonance imaging (MRI). Natalizumab is indicated as monotherapy in adults with active RRMS in Japan. The main objective of this study was to investigate the long-term effect of natalizumab on disease progression in Japanese patients with RRMS using MRI data.
Methods:
This retrospective, chart review study was conducted at a single center in Japan. The main study outcome was the yearly proportion of patients with active T2-weighted image lesions detected with or without Gd enhancement on brain MRI (incidence rate) after treatment initiation for up to 5 years. Additional endpoints included annual relapse rate (ARR) and expanded disability status scale (EDSS) score.
Results:
This study included data from 85 patients with RRMS who had received natalizumab for ≥ 1 year; of these, 65 (76.5%) were female and the mean ± standard deviation (SD) age at baseline was 37.5 ± 10.0 years. The incidence rate of active T2 lesions was 52.9% (45/85) in the year prior to natalizumab treatment (Year - 1), which decreased to 2.4% and 1.6% in Year 0.5-1.5 and Year 1.5-2.5, respectively. No active T2 lesions were detected in Year 2.5-5.5 in patients who continued natalizumab treatment. EDSS score was stable, improved, and worsened in 61.8%, 26.3%, and 11.8% of patients, respectively. The median (range) EDSS score was 2.0 (0.0-7.0) at baseline (n = 85) and remained within a similar range (median score between 1.0 and 2.25 during Years 1-5). ARR decreased from 1.12 relapses per year at baseline to 0.12 relapses per year during Year 1 and remained below 0.15 relapses per year up to Year 5.
Conclusion:
The results of this first long-term study evaluating the effect of natalizumab on MRI activity and clinical outcomes in Japanese patients with RRMS suggest that natalizumab markedly reduced disease activity and maintained effectiveness over several years.
Insights
Natalizumab significantly reduced active MRI lesions and relapses in Japanese relapsing-remitting multiple sclerosis (RRMS) patients over five years. This treatment maintained effectiveness, showing sustained disease control in this cohort.
Area of Science:
- Neurology
- Immunology
- Radiology
Background:
- Relapsing-remitting multiple sclerosis (RRMS) is the most common form of MS.
- Active RRMS is characterized by T2 lesions on MRI, with or without gadolinium enhancement.
- Natalizumab is a treatment option for active RRMS in Japan.
Purpose of the Study:
- To evaluate the long-term effects of natalizumab on disease progression in Japanese RRMS patients.
- To assess natalizumab's impact on MRI-detected disease activity and clinical outcomes over five years.
Main Methods:
- Retrospective chart review of 85 Japanese RRMS patients treated with natalizumab for at least one year.
- Primary outcome: Yearly incidence of active T2 lesions on MRI.
- Secondary outcomes: Annual relapse rate (ARR) and Expanded Disability Status Scale (EDSS) scores.
Main Results:
- The incidence of active T2 lesions decreased from 52.9% pre-treatment to minimal levels (1.6-2.4%) within the first year, with no lesions detected from Year 2.5-5.5.
- ARR decreased from 1.12 to 0.12 relapses/year by Year 1 and remained below 0.15.
- EDSS scores remained stable or improved in 88.1% of patients, with median scores consistently low.
Conclusions:
- Natalizumab markedly reduced MRI-detected disease activity in Japanese RRMS patients.
- The treatment demonstrated sustained effectiveness in reducing relapses and maintaining disability status over five years.
- This study provides long-term evidence of natalizumab's benefits in a Japanese RRMS population.
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