Chronic migraine long-term regular treatment with onabotulinumtoxinA: a retrospective real-life observational study up to 4 years of therapy.

introductionOnabotulinumtoxinA (BoNT-A) was proved effective and safe in chronic migraine (CM) prevention by the Phase III Research Evaluating Migraine Prophylaxis (PREEMPT) and Phase IV Chronic migraine OnabotulinuMtoxinA Prolonged Efficacy open-Label (COMPEL) trials over 1 and 2 years of treatment, respectively. Real-life studies highlighted BoNT-A sustained benefits up to 3 years of administration. Aim of this retrospective real-life study was observing within a 4-year timeframe the progress of a consecutive series of CM patients treated with BoNT-A and evaluating whether long-term quarterly treatment (up to 16 cycles) confirms the outcomes of previous studies over shorter periods of therapy.

methodsOne hundred nine chronic migraineurs were quarterly treated with BoNT-A according to the PREEMPT paradigm. Headache days and hours, analgesics intake and latency time together with disability were analysed at baseline, thereafter bi-annually up to 48 months. Patient responsiveness (improvement in monthly headache days and hours versus baseline) was computed at each study timepoint.

resultsA significant overall decrease from baseline to the 48-month assessment (p < 0.001) was evidenced for the mean number of monthly headache days and hours, analgesics intake and latency time. Severe disability cases significantly decreased at 6 months (p < 0.001), and a progressive shift towards lower degrees of disability was observed at each subsequent timepoint. A gradual percentage increase of responsive cases was observed as treatment was repeated over time. Transitory neck pain was reported in 6 cases.

conclusionsThis study appears to reconfirm the benefits of long-lasting CM prevention with BoNT-A, thus supporting quarterly treatment with BoNT-A over several year.