Background: Chronic migraine is a disabling condition, with limited treatment options. We conducted an open label, single arm, prospective clinical trial, to assess the efficacy and safety of onabotulinumtoxin-A in Greek patients with chronic migraine. Since recent evidence suggests that a meaningful clinical response may be delayed until after a third onabotulinumtoxin-A administration, we aimed at assessing outcomes at this time point.
Methods: A total of 119 patients with CM, scheduled to be treated with Onabotulinumtoxin-A (Botox ®) every 3 months, according to the approved indication and standard clinical practice, were prospectively enrolled. Data documenting changes from baseline (T0-trimester before Onabotulinumtoxin-A first administration) to the period after its third administration (T3) in (i) mean number of monthly headache days (ii) migraine severity as expressed by the mean number of days with peak headache intensity of >4/10 in a 0-10 numerical scale, and (iii) mean number of days with use of any acute headache medication, were collected from patients' headache diaries at each visit.
Results: Of the 119 patients, a total of 81 received 3 courses of onabotulinumtoxin-A and were included in the efficacy population. In those 81 patients, there was a significant decrease in mean headache days/month between T0 and T3 (21.3 ± 5.4 vs 7.7 ± 4.8; P < 0.001); a significant decrease in days with peak headache intensity of >4/10 (11.9 ± 5.5 vs 3.7 ± 3.3; P < 0.001) and finally, the change in days using acute headache medications per month between was also significant (16.2 ± 7.8 vs 5.2 ± 4.3; P < 0.001). Adverse events were few and of non- serious nature.
Conclusion: Our results strongly support the use of onabotulinumtoxin-A for the prophylaxis of CM, as this intervention proved effective, safe and well tolerated in our cohort of Greek patients.
Keywords: Chronic migraine; Migraine; Onabotulinumtoxin-A; Prevention; Prophylaxis; Treatment.