Allison Gandey

June 28, 2010

June 25, 2010 (Los Angeles, California) — New results from the much-anticipated PREEMPT clinical program are in and they show fewer headache days for migraine patients treated with onabotulinumtoxinA.

The results presented here at the American Headache Society 52nd Annual Scientific Meeting show the pooled analysis met its primary endpoint.

"OnabotulinumtoxinA is an effective, safe, and well-tolerated preventive treatment for chronic migraine," presenter David Dodick, MD, from the Mayo Clinic in Scottsdale, Arizona, said at the meeting.

The botulinum neurotoxin is not approved by the US Food and Drug Administration for the treatment of chronic migraine.

The investigators say these results add to the evidence suggesting a potential alternative for difficult-to-treat patients.

Mean reduction in headache duration.

"This is the biggest news out of the meeting," Roger Cady, MD, from the Headache Center in Springfield, Missouri, told Medscape Neurology. "I hope it leads to an indication for use in migraine." Dr. Cady was not involved in the present analysis, but he disclosed that he has done work for Allergan, the study sponsor.

Investigators pooled results from PREEMPT 1 and 2 — double-blind, randomized, placebo-controlled studies. The international collaboration included patients from 122 sites in North America and Europe.

Dr. Dodick showed that not only did onabotulinumtoxinA reduce the duration of headache, treatment also resulted in a statistically significant and clinically meaningful reduction in disability and improved quality of life.

Table 1. Mean Change From Baseline in Medication Satisfaction Questionnaires

MSQ Scores at Week 24 OnabotulinumtoxinA (n = 688) Placebo (n = 696)
Role restrictive 17.0* 8.6
Role preventive 13.1* 6.4
Emotional functioning 17.9* 9.5

MSQ = Migraine Specific Quality of Life Questionnaire

*P < .001.

There were, however, more treatment-related adverse events with the drug and some were serious. There were also more discontinuations with onabotulinumtoxinA.

Table 2. Adverse Events in PREEMPT

Events OnabotulinumtoxinA, % (n = 687) Placebo, % (n = 692)
All 62.4 51.7
Treatment related 29.4 12.7
Serious 4.8 2.3
Treatment related and serious 0.1 0
Discontinuations 3.8 1.2


During an interview, session moderator Michael Cutrer, MD, from the Mayo Clinic in Rochester, Minnesota, said he is encouraged by these results. "This is a novel treatment with a different mechanism of action. It is quite a bit more expensive, but it will be useful for some patients."

Dr. Cutrer told Medscape Neurology he participated on the initial advisory board for PREEMPT and has 8 years experience using the drug in patients. "I was quite skeptical at first, but my clinical experience has changed my mind," he said. Dr. Cutrer suggests that onabotulinumtoxinA might represent a second- or third-line option.

Dr. David Dodick

The last guideline from the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology stated there is "no consistent or strong evidence to permit drawing conclusions on the efficacy of botulinum neurotoxin in chronic daily headache" (Neurology. 2008;70:1707-1714).

Guideline authors led by Markus Naumann, MD, from Augsburg Hospital in Germany, suggested that based on the available data at the time, botulinum neurotoxin is "probably ineffective" in episodic migraine and chronic tension-type headache. In an American Academy of Neurology statement, Dr. Naumann said, "It is no better than placebo injections for these types of headache."

"Although clinicians' practice may suggest stronger recommendations in some of these indications," the guideline writers added, "evidence-based conclusions are limited by the availability of data."

Will these new numbers alter future guidelines? "I hope so," Dr. Cutrer said. "This could represent an important alternative for some patients."

This study was funded by Allergan. Dr. Dodick has received honoraria from the company. Dr. Cady and Dr. Cutrer have also done work for Allergan.

American Headache Society (AHS) 52nd Annual Scientific Meeting: Abstract PL7. Presented June 25, 2010.


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