FDA Approves Therapy for Children with Lower Limb Spasticity

Officials with the FDA have approved Allergan’s supplemental Biologics License Application (sBLA) for onabotulinumtoxinA (BOTOX^®) to expand its indication to include treatment of pediatric patients, ages 2 to 17 years, with lower limb spasticity, excluding spasticity caused by cerebral palsy (CP).

This approval marks onabotulinumtoxinA’s 11th therapeutic indication, according to Allergan. The drug’s other indications include pediatric upper limb spasticity (ULS), which was approved by the FDA earlier this year; and treatment of certain types of muscle eye problems or abnormal spasm of the eyelids in patients age 12 years and older.

Spasticity is a debilitating neurological condition involving muscle stiffness that can result in tight muscles in the upper and lower limbs, and can interfere with movement. The severity can range from mild to severe muscle stiffness.

"Pediatric lower limb spasticity inhibits normal muscular movement and function, and can result in delayed or impaired motor development, as well as difficulty with posture and positioning," said Mark Gormley, Jr., MD, Pediatric Rehabilitation Medicine Specialist, Gillette Children's Specialty Healthcare-St. Paul, in a prepared statement. "BOTOX has a well-established safety and efficacy profile, and supports children and adolescents successfully manage both their upper and lower limb spasticity."

The new FDA approval is based on a Phase 3 study evaluating the safety and efficacy of BOTOX^® in more than 300 pediatric patients aged 2 to 17 years old being treated for lower limb spasticity, according to Allergan. While trial participants had CP, the approved indication excludes lower limb spasticity caused by CP due to marketing exclusivity by another company. These trials included a 12-week, double-blind study and a one-year open-label extension study.

The approved recommended dose per treatment session is 4 Units per kilogram to 8 Units per kilogram divided among affected muscles of the lower limb. The total dose per treatment session in the lower limb should not exceed 8 Units per kilogram or 300 Units, whichever is lower. When treating both lower limbs or upper and lower limbs in combination, the total dose in pediatric patients should not exceed 10 Units per kilogram body weight or 340 Units, whichever is lower, in a 3-month interval.

REFERENCES

FDA Approves BOTOX® (onabotulinumtoxinA) for Pediatric Patients with Lower Limb Spasticity, Excluding Spasticity Caused by Cerebral Palsy [news release]. Dublin, Ireland; October 24, 2019: Allergan website. https://www.allergan.com/News/Details/2019/10/FDA%20Approves%20BOTOX%20onabotulinumtoxinA%20for%20Pediatric%20Patients%20with%20Lower%20Limb%20Spasticity%20Excluding%20Sp. Accessed October 24, 2019.