The Food and Drug Administration (FDA) has approved onabotulinumtoxinA (Botox; Allergan, Madison, NJ) for the treatment of lower limb spasticity in children age 2 to 17 years. This approval is based on a phase 3 study (NCT03017729) evaluating the safety and efficacy of onabotulinumtoxinA in more than 300 children, aged 2 to 17 years old, for treating lower limb spasticity and an open-label extension study (NCT01603641). Although the trial participants had cerebral palsy, the approved indication excludes lower limb spasticity caused by cerebral palsy because marketing exclusivity is held by another company.
The approved dose per treatment session is 4 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. When treating lower limbs or upper and lower limbs in combination, the total dose in children should not exceed 10 Units per kilogram body weight or 340 Units, whichever is lower, in a 3-month interval.
"Lower limb spasticity can impact many aspects of a child's life and have a drastic influence on their overall development and quality of life," said David Nicholson, chief research and development officer, Allergan. "This milestone will continue to support and advance care for children and their caregivers who may be struggling with lower limb spasticity. Here at Allergan, we look forward to continuing to highlight our unwavering attention to innovation and build on our 30-years of research and development efforts with Botox since FDA approval of blepharospasm and strabismus in 1989."
"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. "Botox has a well-established safety and efficacy profile, and supports children and adolescents successfully manage both their upper and lower limb spasticity."
Brad Klein, MD, MBA, FAAN, FAHS, FAANEM, and Raissa Villanueva MD, MPH, FAAN
Claire Smyth, BSc; David Roberts, BSc; and Kenneth Monaghan, PhD
Audrius V. Plioplys, MD