PHILADELPHIA — OnabotulinumtoxinA has demonstrated efficacy, safety, and tolerability in treating chronic migraine, according to research recently presented at the American Headache Society 61st Annual Scientific Meeting held July 11 to 14, 2019, in Philadelphia, Pennsylvania.

This study included 282 adult participants with chronic migraine, all of whom were randomly assigned to receive 3 treatments of onabotulinumtoxinA 155 U every 12 weeks (n=140) or topiramate titrated from 50 to 100 mg/day (n=142) for up to 36 weeks. Switching to onabotulinumtoxinA was permitted for those who discontinued topiramate at 36 weeks or more. A 2-week taper and initiation of onabotulinumtoxinA was used to discontinue topiramate. Study researchers recorded adverse events at each visit. Exploratory endpoints consisted of responder rates ≥30%, ≥50%, and ≥70% improvement from baseline in monthly headache days, total baseline change in Headache Impact Test (HIT-6) scores, and baseline change in frequency of monthly headache days.

Among the study population, 60 participants experienced an adverse event with topiramate that caused them to discontinue, while 80 switched to onabotulinumtoxinA from topiramate. Of the 80 participants, 89% did so at 12 weeks or more. The groups responded as follows.

At 30% or higher, responder rates were:

  • Week 24: 44.9% (n=35) of the crossover group vs 52.9% (n=74) of onabotulinumtoxinA group
  • Week 36: 46.3% (n=37) and 47.9% (n=67), respectively
  • Week 48: 37.5% (n=30) of the crossover group.

At 50% or higher, responder rates were:

  • Week 24: 30.8% (n=24) and 36.4% (n=51), respectively
  • Week 36: 41.3% (n=33) and 37.1% (n=52), respectively
  • Week 48: 27.5% (n=22) of the crossover group. 

At 70% or higher, responder rates were:

  • Week 24: 17.9% (n=14) and 22.1% (n=31), respectively
  • Week 36: 18.8% (n=15) and 22.9% (n=32), respectively
  • Week 48: 21.3% (n=17) of the crossover group.

Related Articles

Among the crossover group, frequency of monthly headache days showed a mean baseline change of -6.3 (Standard Deviation [SD] 7.2) at week 24, -6.5 (SD 7.8) at week 36, and -5.3 (SD 7.9) at week 48. Mean HIT-6 baseline reductions were -3.0 (SD 5.3) at week 18, -4.0 (4.7) at week 30, and -2.9 (6.0) at week 42. Topiramate was associated with 112 adverse reactions (78.9% of participants), while onabotulinumtoxinA was associated with 105 adverse reactions (47.7% of participants). Participants in the crossover group experienced 38 (47.5%) adverse events. Sinusitis (7.5%; n=6), migraine (5.0%; n=4), and neck pain (6.3%; n=5) were the most common reported adverse events among the crossover population. No discontinuations occurred in the crossover group due to an adverse event with onabotulinumtoxinA. 

Study researchers concluded that “treatment with onabotulinumtoxinA is associated with reductions in monthly migraine days and is safe and well tolerated in patients with [chronic migraine] who switch from topiramate.”

This study received support from Allergan, PLC in Dublin, Ireland.

Reference

Rothrock J, Lipton R, Young W, Jo E, Manack Adams A, Blumenfeld A. OnabotulinumtoxinA is safe and effective in patients who discontinue topiramate: results of the FORWARD study. Poster presented at: American Headache Society 61st Annual Scientific Meeting; July 11-14, 2019; Philadelphia, PA. Submission 628264.