Allergan plc announced that the U.S. Food and Drug Administration (FDA) has approved BOTOX (onabotulinumtoxinA) for the treatment of lower limb spasticity in adult patients to decrease the severity of increased muscle stiffness in ankle and toe muscles. BOTOX is the first and only botulinum toxin product to be approved by the FDA to treat multiple muscle groups of the upper (elbow, wrist, fingers, and thumb) and lower limbs that may be impacted by spasticity. BOTOX was first approved for the treatment of upper limb spasticity (ULS), or increased muscle stiffness in the elbow, wrist and fingers, in adults in March 2010.

Additional FDA approval was received in April 2015 to expand the BOTOX label for the treatment of adults with ULS to include the addition of two thumb muscles. It is not known whether BOTOX is safe or effective to treat increased stiffness in upper limb muscles other than those in the elbow, wrist, fingers, and thumb, or to treat increased stiffness in lower limb muscles other than those in the ankle and toes. BOTOX has not been shown to help people perform task-specific functions with their upper limbs or increase movement in joints that are permanently fixed in position by stiff muscles.

Treatment with BOTOX is not meant to replace existing physical therapy or other rehabilitation that doctor may have prescribed. The FDA approval was based on a large, international development program that included a phase three, multi-center, double-blind, randomized, placebo-controlled clinical trial that evaluated the safety and efficacy of BOTOX compared to placebo in more than 400 patients with lower limb spasticity following stroke. The study compared a total BOTOX dose of 300 to 400 units divided among ankle and toe muscles (n=233) to placebo (n=235).

Statistically significant improvements were observed in the two co-primary endpoints of average change from baseline in the improvement of muscle tone measured by the Modified Ashworth Scale (MAS) ankle score and the clinical benefit for patients as assessed by the Clinical Global Impression of Change by Physician (CGI) at weeks 4 and 6 (p<0.05). The most frequently reported adverse reactions (>2%) were arthralgia (3%), back pain (3%), myalgia (2%), upper respiratory tract infection (2%) and injection site pain (2%). The safety profile observed in the study was consistent with the known safety profile of BOTOX.

BOTOX® (onabotulinumtoxinA) is a prescription medicine that is injected into muscles and used to treat increased muscle stiffness in elbow, wrist, finger, thumb, ankle, and toe muscles in people 18 years and older with upper and lower limb spasticity. It is not known whether BOTOX is safe or effective to treat increased stiffness in upper limb muscles other than those in the elbow, wrist, fingers, and thumb, or to treat increased stiffness in lower limb muscles other than those in the ankle and toes. BOTOX has not been shown to help people perform task-specific functions with their upper limbs or increase movement in joints that are permanently fixed in position by stiff muscles.

Treatment with BOTOX is not meant to replace existing physical therapy or other rehabilitation that doctor may have prescribed. BOTOX may cause serious side effects that can be life threatening. Get medical help right away if have any of these problems any time (hours to weeks) after injection of BOTOX: Problems swallowing, speaking, or breathing, due to weakening of associated muscles, can be severe and result in loss of life.

The effect of botulinum toxin may affect areas away from the injection site and cause serious symptoms including: loss of strength and all-over muscle weakness, double vision, blurred vision and drooping eyelids, hoarseness or change or loss of voice, trouble saying words clearly, loss of bladder control, trouble breathing, trouble swallowing. BOTOX may cause loss of strength or general muscle weakness, vision problems, or dizziness within hours to weeks of taking BOTOX. If this happens, do not drive a car, operate machinery, or do other dangerous activities.

The dose of BOTOX is not the same as, or comparable to, another botulinum toxin product. Other side effects of BOTOX include: dry mouth, discomfort or pain at the injection site, tiredness, headache, neck pain, and eye problems: double vision, blurred vision, decreased eyesight, drooping eyelids, swelling of eyelids, and dry eyes.