A significant number of patients with chronic migraine treated with onabotulinumtoxinA experience wear-off, according to new data published in Headache.

The retrospective chart review was conducted to evaluate the frequency and features of onabotA wear-off in chronic migraine patients. 

“In our clinical experience, many patients who receive benefit from onabotA experience worse headaches in the time leading up to their next scheduled 12-weeks onabotA administration, which  clinicians and patients may frame as a wear-off phenomenon and could prompt clinicians to consider,” Alina Masters- Israilov, MD, from the Saul R. Korey Department of Neurology, Montefoire Medical Center in the Bronx, NY, and colleagues wrote in the study. “The phenomenon of onabotA wear-off in the treatment of chronic migraine remains underexplored and we aimed to evaluate its rate, associated factors, features, and treatment characteristics.”

Man receiving onabotA injection. Source: Getty

The review was conducted of 143 patients with CM initiated on onabotA over a 2‐year period.

Wear‐off was considered present with the phrase documented, a quantitative headache day increase, or increased use of abortive medications, bridging therapies or emergency department visits in the 6 weeks preceding the subsequent administration, according to the study. 

It was found that 90 of the 143 patients included in the study experienced wear-off (62.9%).

According to the study, age, sex, medication overuse, psychiatric comorbidity, injector training level, and mean days between injections did not differ between the two study groups. 

There were significantly fewer mean units injected per session until first documented wear-off among patients in the wear-off group when compared to those in the no wear-off group (166.0 ± 13.1 vs 173.4 ± 10.3, P = .0005). 

Wear‐off most typically occurred 2‐4 weeks before the next injection (43.3%) and after the very first injection (40.0%).

The most common bridge therapies used in the wear-off period were intramuscular ketorolac injections (33.3%) and peripheral nerve blocks (25.6%).

Mean units injected per session in the wear‐off group until first documented wear‐off were significantly less vs no wear‐off group (166.0 ± 13.1 vs 173.4 ± 10.3, P  = .0005). 

Wear‐off most commonly occurred 2‐4 weeks before the next injection (43.3%) and after the very first injection (40.0%). Intramuscular ketorolac injections (33.3%) and peripheral nerve blocks (25.6%) were the most common bridge therapies used in the wear‐off period.

The researchers suggest that based on the findings of the study, physicians should consider increasing the units used from the treatment onset to reduce the frequent need for bridging therapies. 

 “Future prospective studies incorporating patient diaries focusing on wear-off and randomization of patients to different starting doses of onabotA may help verify our findings. In addition, the publication of daily or weekly diary studies from clinical trials which seem to be available may also help to explore the phenomenon of wear-off of onabotA in chronic migraine.,” the wrote. “Comparison to other therapies administered over a 12-week basis, such as the calcitonin gene-related peptide monoclonal antibody fremanezumab, may serve as a useful comparator to assess for wear-off across therapies with similar dosing timelines but different mechanisms of action”