FDA Approves Botox for Elbow Spasms. Are Migraines Next?
"Muscles affected by spasticity have increased stiffness and tightness, which may lead to pain, difficulties with hygiene and other activities of daily living, and may affect how a patient looks," says Dr. Russell Katz, director of the Division of Neurology Products in the FDA's Center for Drug Evaluation and Research. Botox, injected into the affected muscles, blocks the connections between nerves and muscles, paralyzing the spastic muscle for an average of up to three months in clinical trials.
Sweating, Spasm...and Migraines?
Because the active ingredient in Botox is the highly poisonous botulinum toxin, the FDA last year required Allergan to warn that the effect of Botox could spread from the area of injection to other areas of the body, causing symptoms similar to those of botulism, including potentially life-threatening difficulty with swallowing and breathing.
The FDA further stressed that Botox has not been proved a safe, effective treatment for larger muscles such as those in the legs and others in the upper limbs. Nor is it safe for treatment of fixed contracture, a condition that affects range of motion. The most common adverse reactions were nausea, fatigue, bronchitis, muscle weakness and pain in the arms.
Although better known for its cosmetic applications, Botox is approved to treat such therapeutic conditions as underarm sweating, neck spasms, and eye-muscle disorders. Therapeutic sales of Botox accounted for approximately 52% of Allergan sales last year and increased about 4% over 2008. Cosmetic sales accounted for approximately 48% and decreased approximately 4%. Allergan is testing Botox for other medical uses, including migraines, which may be the most significant area for the drug's future sales growth.
While Botox's FDA-approved uses may be limited, doctors are allowed to prescribe it in unapproved ("off-label") treatments for muscle spasms. But pharmaceutical companies are prohibited from promoting off-label uses. Last year, Eli Lilly (LLY) paid a $1.42 billion fine, and Pfizer (PFE) paid a record $2.3 billion fine, to settle charges of off-label promotions.
Allergan has sued the FDA, arguing that these rules violate its First Amendment right to free speech. It wants to be allowed to "share relevant information with the medical community on the safe use" of Botox for off-label uses. Tuesday's approval, demonstrating that the FDA doesn't hold a grudge, eases investors' concerns on that front. Botox sales rose 5.6% last quarter, to $347.7 million, and Allergan forecasts full-year 2010 net sales of $1.33 billion to $1.37 billion. Allergan shares rose some 1.8% in morning trading.
While therapeutic uses may continue to fuel increases, cosmetic uses may too: Despite the recession, plastic surgeries declined only 2% in 2009 -- nearly 10 million procedures in the U.S. included 2.5 million procedures involving botulinum toxin type A (whether Botox or rival Ipsen Group's Tercica's Dysport).