PracticeUpdate Conference Series - ANZAN 2018

" …staying on natalizumab longer than 2 years yielded better clinical outcomes than switching to oral or injectable therapies. "

(HR 12.184 [95% CI 1.552–95.634]; P = .017). Adverse events were consistent with known safety profiles. Dr. Butzkueven concluded that the results sug- gested that natalizumab reduces disease activity more rapidly and to a greater extent than fingoli- mod in patients with active RRMS. Given the early study closure, available data did not permit primary endpoint evaluation. Interpretation of these results requires caution. Dr. Butzkueven and colleagues then set out to com- pare clinical outcomes of patients with RRMS who remained on natalizumab vs those who switched to oral or injectable therapies after 2 years in the Tysabri® Observational Program. Dr. Butzkueven explained that natalizumab is a high-efficacy therapy for RRMS, and data on post-natalizumab disease activity may be important. Dr. Butzkueven and colleagues compared outcomes in patients who switched to an oral or injectable therapy vs those in patients who remained on natalizumab. They analyzed post-natalizumab relapse predic- tors using data from the Tysabri® Observational Program, an ongoing 10-year observational study of patients with RRMS who were treated with natalizumab.

Data were analyzed for patients who stayed on natalizumab (≥3 years natalizumab and only natal- izumab during follow-up; n=2466; mean time on natalizumab 5.5 years). The comparison group switched to oral (n=660) or injectable (n=95) therapies for at least 1 year after ≥2 years on natalizumab (mean post-natalizumab follow-up duration 2.5 vs 2.4 years). Annualized relapse rates and risk of Expanded Disability Status Scale (EDSS) score worsening were evaluated. Disease activity predictors were compared using adjusted Cox models. Relapse risk was higher for oral switchers (HR 2.18; P < .001) or injectable switchers (HR 3.02; P < .001) than for patients who remained on natalizumab for over 2 years. Risk of EDSS score worsening was similar for oral (HR 1.19) and higher for injectable (HR 2.52; P < .001) switchers than for patients who stayed on natalizumab.

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ANZAN 2018 • PRACTICEUPDATE CONFERENCE SERIES