Most patients who responded to Botox treatment for migraine at six months continued to do so at two years, with many showing a response even after cessation of treatment.
SAN DIEGO—Among 123 patients who responded to treatment with onabotulinumtoxinA (Botox) for chronic migraine at six months, most continued to show a response at two years—and 25% did so despite the cessation of treatment consequent to their positive response. Those were the findings of Christopher Hanlon, MD, an intern at the University of Alabama School of Medicine (UASM), Birmingham, and colleagues, as presented at the 136th Annual Meeting of the American Neurological Association.
About 40% to 45% of patients with chronic migraine show a favorable response to onabotulinumtoxinA therapy at six months, according to study coauthor John F. Rothrock, MD, Professor, Vice Chair, and Medical Director of the Department of Neurology at UASM. “This short-term response was observed in the pivotal trials that won the treatment its FDA approval for chronic migraine,” he told Neurology Reviews. “But given that the drug was not approved until October 2010, very few clinicians or clinical scientists have long-term experience with the treatment in the ‘real world’ setting.”
The researchers followed 123 patients for at least two years and a mean of 2.76 years. All patients had shown a treatment response at six months, as indicated by a 50% or greater reduction in headache days per month.
Of the patients, 82 (67%) continued to respond to onabotulinumtoxinA but required ongoing injection therapy throughout the follow-up period. An additional 31 patients (25%) were able to stop therapy and remain largely free of migraine for a minimum of six months during follow-up. Only 10 patients (8%) experienced relapse to chronic migraine despite ongoing treatment, and only one serious adverse event occurred during follow-up—a prolonged migraine attack that required brief hospitalization.
The finding that many patients can cease therapy without relapsing is unique and merits further investigation, Dr. Rothrock said. “What proportion of Botox responders eventually will be able to stop treatment?” he asked. “Our research suggests the proportion is substantial, but how to identify those patients and, specifically, how to know when to stop treatment remain open questions.”
—Jack Baney