OnabotulinumtoxinA treatment among diverse racial groups: Post hoc analysis of the phase 4 Chronic migraine OnabotulinuMtoxinA Prolonged Efficacy open-Label (COMPEL) trial.

objectiveExamine treatment responses to and safety of onabotulinumtoxinA for the preventive treatment of chronic migraine (CM) among diverse racial groups.

backgroundEvidence suggests there are differences in headache treatment patterns, symptom profiles, and burden based on race. However, limited data are available describing the response to preventive migraine treatments among these groups.

methodsThe Chronic Migraine OnabotulinuMtoxinA Prolonged Efficacy open Label (COMPEL) trial was a single-arm, open-label, multicenter, prospective study (January 23, 2012-November 16, 2015) that enrolled adults of various races with CM to receive onabotulinumtoxinA 155 U every 12 weeks over 108 weeks. These analyses assessed White, Asian (primarily Republic of Korea residents), and Black/African American subgroups based on self-report. Pacific Islander/American Indian/Alaska Native and Hispanic/Latinx subgroups were not analyzed separately because of the small sample sizes and potential overlap with predefined racial categories (e.g., Hispanic/Latinx White) for the latter. Analyses of baseline demographics and clinical characteristics, including headache features, across the subgroups were performed. Change from baseline in the number of monthly headache days (MHDs), including proportions with ≥50% reduction in MHDs, and change from baseline scores on the 6-item Headache Impact Test (HIT-6), Migraine Disability Assessment (MIDAS) absenteeism, presenteeism, and total scores, and Migraine-Specific Quality of Life questionnaire version 2.1 (MSQ v2.1) Role Function-Restrictive (RFR), Emotional Function (EF), and Role Function-Preventive (RFP) domains were evaluated for each subgroup.

resultsOf 716 enrolled participants, 582 (81.3%) were White, 89 (12.4%) were Asian, 41 (5.7%) were Black/African American, and 4 (0.6%) were Pacific Islander/American Indian/Alaska Native. Withdrawal from the study occurred for 50.5% of the White subgroup, 32.6% of the Asian subgroup, and 48.8% of the Black/African American subgroup. The most common reasons for study discontinuation were participant withdrawal of granted consent (12.8%) and lost to follow-up (11.5%). After treatment with onabotulinumtoxinA 155 U every 12 weeks, all subgroups demonstrated significant reductions from baseline in MHDs at all time points to week 108 (all p < 0.001) and 60.3%-73.3% experienced ≥50% reduction from baseline in MHDs at week 108. Each analyzed subgroup demonstrated significant reductions from baseline to week 108 in HIT-6 total (all p < 0.001), MIDAS total (White, p < 0.001; Asian, p < 0.001; Black/African American, p = 0.0062), MIDAS absenteeism (White, p < 0.001; Asian, p < 0.001; Black/African American, p = 0.002), MIDAS presenteeism (all p < 0.001), MSQ v2.1 RFR (all p < 0.001), MSQ v2.1 EF (White, p < 0.001; Asian, p < 0.001; Black/African American, p = 0.009), and MSQ v2.1 RFP (all p < 0.001) scores. Results in the total population were similar to those in the subgroups. Treatment-related adverse events were consistent with the known safety profile of onabotulinumtoxinA.

conclusionsOnabotulinumtoxinA safely reduced MHD frequency and patient-reported disability and improved quality of life as a preventive treatment of CM among diverse subgroups, with results directionally consistent among groups.

trial registrationCOMPEL, ClinicalTrials.gov identifier: NCT01516892.