Allergan's Botox reduces migraine headache days

LOS ANGELES, Sept 10 (Reuters) - Botox, the popular wrinkle-smoother sold by Allergan Inc AGN.N, significantly reduced the number of headache days for adults suffering from chronic migraines, according to two late-stage trials.

Top-line results from the studies were announced a year ago, but the full data will be presented for the first time this weekend at a meeting of the International Headache Society in Philadelphia.

In one 679-patient trial, patients injected with Botox had headaches on 7.8 fewer days each month, compared with a drop of 6.4 days in the placebo group. In a second trial involving 705 migraine sufferers, Botox-treated patients had nine fewer headache days compared with a drop of 6.7 days for the placebo group.

Allergan had previously announced that the first trial missed its primary goal for reducing the number of headache episodes compared with placebo but did meet a secondary goal of reducing the number of headache days.

“Overall, the phase III data are in-line with our expectations, namely, that the efficacy of Botox for chronic migraines is superior to placebo and at least comparable to that of Topamax which is approved for migraine prevention,” Wachovia analyst Larry Biegelsen said in a research note.

Johnson & Johnson's JNJ.N Topamax, or topiramate, is primarily used to treat epilepsy.

Allergan plans to file this month for U.S. regulatory approval of Botox, or botulinum toxin type A, for treatment of chronic migraine, which affects an estimated 1.2 million to 3.6 million people in the United States.

Biegelsen estimated that the market represents a $500 million opportunity for Botox.

In afternoon trading, Allergan shares were up $1.11 or 2 percent at $57.28 in afternoon New York Stock Exchange trading. (Reporting by Deena Beasley, editing by Gerald E. McCormick)