Sustained onabotulinumtoxinA therapeutic benefits in patients with chronic migraine over 3 years of treatment

Background Evidence on whether the therapeutic effect and good safety profile of onabotulinumtoxinA (Botox®) in chronic migraine (CM) patients is maintained over long term treatment is still limited. We herein aimed at assessing whether there is a sustained benefit and good safety with repeated onabotulinumtoxinA sessions in CM over more than three years of treatment.