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OnabotulinumtoxinA for treatment of chronic migraine: results from the double-blind, randomized, placebo-controlled phase of the PREEMPT 2 trial. Cephalalgia 2010 Jul;30(7):804-14 PMID: 20647171

Pubmed ID





OBJECTIVES: This is the second of a pair of studies designed to evaluate the efficacy and safety of onabotulinumtoxinA (BOTOX) for prophylaxis of headaches in adults with chronic migraine.

METHODS: PREEMPT 2 was a phase 3 study, with a 24-week, double-blind, placebo-controlled phase, followed by a 32-week, open-label phase. Subjects were randomized (1:1) to injections of onabotulinumtoxinA (155U-195U; n = 347) or placebo (n = 358) every 12 weeks for two cycles. The primary efficacy endpoint was mean change in headache days per 28 days from baseline to weeks 21-24 post-treatment.

RESULTS: OnabotulinumtoxinA was statistically significantly superior to placebo for the primary endpoint, frequency of headache days per 28 days relative to baseline (-9.0 onabotulinumtoxinA/-6.7 placebo, p < .001). OnabotulinumtoxinA was significantly favoured in all secondary endpoint comparisons. OnabotulinumtoxinA was safe and well tolerated, with few treatment-related adverse events. Few patients (3.5% onabotulinumtoxinA/1.4% placebo) discontinued due to adverse events.

CONCLUSIONS: The results of PREEMPT 2 demonstrate that onabotulinumtoxinA is effective for prophylaxis of headache in adults with chronic migraine. Repeated onabotulinumtoxinA treatments were safe and well tolerated.

Author List

Diener HC, Dodick DW, Aurora SK, Turkel CC, DeGryse RE, Lipton RB, Silberstein SD, Brin MF, PREEMPT 2 Chronic Migraine Study Group


Frederick G. Freitag DO Associate Professor in the Neurology department at Medical College of Wisconsin


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MESH terms used to index this publication - Major topics in bold

Botulinum Toxins, Type A
Chronic Disease
Double-Blind Method
Middle Aged
Migraine Disorders
Neuromuscular Agents
Treatment Outcome
Young Adult
jenkins-FCD Prod-321 98992d628744e349846c2f62ac68f241d7e1ea70