UK use of natalizumab

Over a third of UK MSers on natalizumab are 1st-line users #MSBlog #MSResearch

"The data on 117 MSers on natalizumab in the UK who are enrolled in the TOP study is keeping with the trial data. What is surprising that over a third of MSers went onto the drug as a first-line treatment. It is reassuring that none of the MSers in this study have developed PML."


Hanna et al. Efficacy and safety of natalizumab treatment for relapsing-remitting multiple sclerosis: interim results of the tysabri(r) observational programme in the uk J Neurol Neurosurg Psychiatry. 2013;84(11):e2.

INTRODUCTION: The natalizumab (TYSABRI®) Observational Program (TOP) is an ongoing, open-label, 10-year prospective study of RRMSer in European, Australian, and Canadian clinical settings. MSers must be naïve to natalizumab when deciding to enrol but may have received other disease-modifying therapies (DMTs) pre-natalizumab. The objective of this analysis was to evaluate interim efficacy and safety data in the subset of MSers in the United Kingdom (UK).

METHODS: Baseline characteristics were summarised. Annualised relapse rate (ARR) was analysed for overall pre-and post-baseline differences as well as by treatment and relapse histories at baseline. Expanded Disability Status Scale (EDSS) scores were evaluated at baseline and years 1 and 2. The incidence of serious adverse events (SAEs) was evaluated.

RESULTS: As of June 1, 2012, 117 patients were enrolled in the UK. Most (80.3%) were female; mean age was 39.1 years. The median duration of RRMS was 5.6 (range 0.4-25.3) years. The median number of relapses in the year prior to natalizumab treatment was 2.0 (range 1.0-6.0); 24.8% of patients had 1 relapse and 75.2% had >1 relapse in the prior year. At baseline, 35.0% of patients were treatment naïve, 49.6% were treated with 1 DMT, and 15.4% were treated with >1 DMT prior to natalizumab. Approximately half (51.3%) had a history of interferon use, 25.6% had a history of glatiramer acetate use, and 1.7% had a history of immunosuppressant use. Most MSers (60.7%, n=71) have been followed for at least 12 months; 39.3% (n=46) have been followed for at least 18 months. MSers received a median of 15 (range 1-27) natalizumab infusions. ARR overall decreased from 2.26 at baseline to 0.38 on treatment (n=117; P<0.0001). ARR decreased significantly from baseline regardless of baseline treatment history (treatment naïve [n=41]: 2.54 at baseline vs 0.48 on treatment, P<0.0001; 1 prior DMT [n=58]: 2.14 at baseline vs 0.36 on treatment, P<0.0001; >1 prior DMT [n=18]: 2.00 at baseline vs 0.26 on treatment, P=0.0003) or relapse history (1 relapse in prior year [n=29]: 1.00 at baseline vs 0.27 on treatment, P<0.0001); >1 relapse [n=88]: 2.67 at baseline vs 0.43 on treatment, P<0.0001). EDSS scores were stable with a mean of 4.2 at baseline (n=115), 4.0 at month 6 (n=33), 4.4 at year 1 (n=19), and 4.3 at year 2 (n=9). No cases of progressive multifocal leukoencephalopathy, malignancy, or opportunistic infections were reported.

CONCLUSIONS: In this interim analysis of UK TOP results, MSers treated with natalizumab had significantly improved ARRs, regardless of baseline treatment or relapse history. EDSS scores remained stable over time. Safety data were consistent with natalizumab's known safety profile. Analyses of UK TOP data over longer periods of time will further characterise the effect of natalizumab on disability, as well as on other long-term efficacy and safety parameters in a real-world setting.

CoI: multiple

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