Daily treatment with Janssen Cilag’s Topamax significantly reduces chronic migraine, according to results from a clinical trial reported at the 8th European Headache Federation (EHF), held in Valencia, Spain.

Topamax (topiramate) cut the number of days migraine was suffered by 3.5 per month versus no significant change on placebo. Significant improvements in quality of life were also observed using the MIDAS questionnaire.

The 59-patient study, TOP-CHROME (TOPiramate in CHROnic MigrainE), enrolled migraineurs who suffered a total of 15 or more migraine days a month. Unlike previous studies, patients who overused acute medications were included in the study - these patients also experienced a significant and clinically relevant reduction in migraine days.

“Topiramate at a mean dose of 100mg reduced both migraine days and intake of acute medication in people with chronic migraine, the majority of whom had medication overuse. These results should change the way we manage patients with chronic migraine,” said principal investigator Prof Hans-Christoph Diener, of the University of Essen, Germany.

“A 30% reduction in migraine days is extremely meaningful for a patient who is having 20 days of migraine per month,” he added.

Topiramate was originated as a drug for epilepsy and is currently also approved for episodic migraine, but not chronic migraine, which is suffered by some thirty million people in Europe. “People with chronic migraine have been excluded from previous clinical trials because the prevailing opinion was that preventive therapy would not work in chronic migraine,” said Prof Diener.

A spokesman for Janssen Cilag, a subsidiary of Johnson & Johnson, said that the results were interesting, but further confirmatory studies would be needed before any application could be made to extend the drug’s license to include chronic migraine.

Topamax is one of J&J’s best-performing products at present, with growth of 16% in the first quarter of this year to reach $471 million.

By Ian Mason