Drugmaker Allergan said Thursday it has new evidence that its injectable drug can help relieve migraine headaches. Based on preliminary results from two company-funded studies, Allergan said it will ask the Food and Drug Administration to approve Botox for chronic migraine next year.
The FDA approved Botox to smooth wrinkles and age lines in 2002, and it has grown into a blockbuster product for Allergan, with $2.1 billion in sales last year. Doctors inject the drug directly into patients' foreheads every four months, paralyzing facial muscles that create wrinkles.
Although Botox is not approved by the FDA for treating migraines, doctors have been using it in that way off-label.
Allergan compared results for migraine patients who received either Botox or a dummy injection every 12 weeks. In the company's first study there was no difference in the number of overall headaches reported by patients taking Botox versus the dummy injection. However, Allergan said there was a significantly lower number of "headache days" reported by Botox patients. According to the company, FDA considers migraine days a more accurate treatment measure.
A second company study showed lower rates of migraines and migraine days for patients in the Botox group, according to Allergan.
Shares of Irvine, Calif.-based Allergan leapt on the news, rising $5.85, or 10.7 percent, to $60.41 in midday trading.
Buckingham Research Group analyst David Buck did not adjust his earnings projections for Botox, which he expects to rise a modest 7 percent in 2009, compared with 13 percent this year. Buck said Botox sales will be challenged by the economic downturn and new competing products.
Botox is a purified form of the deadly toxin that causes botulism. While best known for its cosmetic uses, the drug is also used to treat a variety of muscle-spasm conditions, such as severe neck spasms.
Earlier this year the FDA added new warnings to Botox about rare but deadly side affects seen in some patients. According to FDA, the drug occasionally spreads from the injection site, paralyzing muscles used to breathe and swallow.
The agency warned doctors and patients to watch for symptoms of botulism, including difficulty swallowing or breathing, slurred speech and muscle weakness.