OnabotulinumtoxinA benefits patients with chronic migraine regardless of response status
Treatment with onabotulinumtoxinA significantly improves headache-related outcomes in patients with chronic migraine (CM) regardless of their response status, according to a study presented at AHS 2019.
The researchers conducted a pooled analysis of data from the phase III PREEMPT* clinical programme comprising a 24-week double-blind phase (two treatment cycles) and a 32-week open-label phase (three treatment cycles).
A total of 1,384 patients with CM were involved in the study and were stratified, based on their response to treatment, into two subgroups: responders** and nonresponders***. All patients were randomly assigned to receive either onabotulinumtoxinA (n=688, 308 responders and 380 nonresponders) or placebo (n=696, 238 responders and 458 nonresponders) for 24 weeks. HIT-6+ and MSQ++ scores were used to assess the impact of migraine on daily functioning. [AHS 2019, abstract P14]
Among nonresponders, those treated with onabotulinumtoxinA had a significantly greater reduction in the number of moderate/severe headache days from baseline than those who received placebo (p<0.02).
At 24 weeks, onabotulinumtoxinA-treated nonresponders were less affected by migraine, as shown by greater improvements in the HIT-6 scores from baseline, compared with the placebo-treated nonresponders (-2.3 vs -0.8; p<0.001).
Greater improvements were also seen across all domains in the MSQ score, namely the restrictive (8.8 vs 2.9; p<0.001), preventive (6.0 vs 1.8; p<0.001), and emotional domains (8.5 vs 2.8; p<0.001), among nonresponders treated with onabotulinumtoxinA compared with placebo.
In addition, a significant between-treatment difference was already evident among nonresponders who received onabotulinumtoxinA compared with placebo at weeks 4 (p<0.001 for HIT-6 score) and 12 (p<0.02 for MSQ score), which was sustained through 24 weeks.
The differences in HIT-6 and MSQ scores were also evident at weeks 8 (p<0.02) and 12 (p<0.05), respectively, which were also sustained at 24 weeks among responders treated with onabotulinumtoxinA than placebo.
“The above results support a treatment benefit of onabotulinumtoxinA in [patients with] CM at 24 weeks that may not be fully captured by the observed reduction in headache days,” said the researchers.
The findings are consistent with another study showing that patients treated with onabotulinumtoxinA demonstrated at least a 50 percent improvement in migraine burden even before starting another treatment, said the researchers, who highlighted that “onabotulinumtoxinA injections are a clinically approved therapy for the treatment of CM.” [AHS 2019, abstract P09]
“OnabotulinumtoxinA treatment was associated with significantly greater improvements than placebo in headache severity, headache-related impact, and quality of life in both headache-day responders and nonresponders as typically defined solely by an arbitrary and binary 50 percent cut-off [≥50 percent reduction in headache days],” the researchers added.
*PREEMPT: Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy
**Responders: Defined as ≥50 percent reduction in headache days from baseline
***Nonresponders: Defined as <50 percent reduction in headache days from baseline
+HIT-6: 6-domain Headache Impact Test
++MSQ: Migraine-Specific Quality of Life Questionnaire