FDA approves Botox (onabotulinumtoxinA) for lower limb spasticity- Allergan

The FDA has approved Botox (onabotulinumtoxinA), from Allergan, 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.

The FDA approval was based on a large, international development program that included a phase III, 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.