The Food and Drug Administration has delayed the approval of using Botox to treat upper limb spasticity, or loss of muscle function and tone, asking for more information. The delay was announced Tuesday.
Irvine-based Allergan Inc. had submitted the drug to treat muscle loss in stroke victims, but the FDA suggested a broader use for the drug, which is a purified form of a toxin related to botulism, a type of food poisoning.
The FDA asked Allergan to conduct a post-approval study of using Botox for muscle loss, regardless of the cause, in patients ages 2 to 17.
Allergan shares were flat Wednesday with a market value of $13.5 billion.
The delay held silver linings for the drug maker because the FDA did not ask for additional clinical studies, which could take additional months or years.
Allergan has said it can provide reports to FDA in two to three months.
This comes at a time when Botox? cosmetic uses have taken some hits. Botox sales were down 6% to $297.3 million in the first quarter.
Some investors are worried that Allergan, which holds more than 80% of the market for toxin-based drugs, could take bigger hits from new competitors.
Late last month, the FDA cleared Dysport for cosmetic and medical uses in the U.S.?llergan? first domestic competitor for its wrinkle-removing drug Botox Cosmetic.
Dysport is expected to cost 20% less than Botox and could attract up to a third of the market, according to some analysts.
Some predict that medical sales of Botox eventually could overtake its cosmetic uses.
