FDA Accepts Botox Applications for Pediatric Limb Spasticity

The US Food and Drug Administration (FDA) has accepted supplemental Biologics License Applications (sBLA) for onabotulinumtoxinA (Botox) that seek to extend the drug label to include pediatric patients with upper and lower limb spasticity.

If approved, the injection would be available for use in children 2 to 17 years of age in addition to the currently approved use in adults with upper and lower limb spasticity.

"The FDA's acceptance of Allergan's supplemental biologics license applications is a monumental milestone on our journey to bring new treatment options to pediatric patients with upper and lower limb spasticity," said David Nicholson, Chief Research and Development Officer, Allergan, in a statement.

The indication for pediatric upper limb spasticity has been given Priority Review, which gives it a 6-month review process. A Prescription Drug User Fee Act (PDUFA) date and decision from the FDA is expected in the second quarter of this year. The pediatric lower limb spasticity indication will be reviewed by the FDA in the standard 10 months, with a PDUFA date expected in the fourth quarter of 2019.

The 2 applications are supported by results from 4 phase 3 studies of onabotulinumtoxinA in children with upper and lower limb spasticity. Allergan has sponsored a placebo-controlled trial and open-label extension study for both upper and lower limb spasticity separately.

"Pediatric spasticity is a significant concern and can negatively impact a child's development and quality of life, interfering with everyday activities such as walking, dressing, and playing," said Heakyung Kim, MD, Pediatric Rehabilitation Medicine at Columbia University Medical Center/New York Presbyterian Hospital, in a statement. Kim, an investigator on the studies, added that managing spasticity in pediatric care is especially important due to the negative effects of long-term spasticity.

The placebo-controlled, double-blinded study of onabotulinumtoxinA in children 2 to 16 years of age with upper limb spasticity included 235 patients who were randomized to one intramuscular injection of onabotulinumtoxinA 3 units/kg or 6 units/kg, or placebo.

Both active treatment groups demonstrated a significant reduction in Modified Ashworth Scale&#8208;Bohannon scores compared to placebo (onabotulinumtoxinA 6 units/kg, - 1.87; onabotulinumtoxinA 3 units/kg, -1.92; P <.001). The improvement was significant at all assessments during the 12-week trial.

A second placebo-controlled, double-blinded study examined 384 children with lower limb spasticity who were randomized to one intramuscular injection of onabotulinumtoxinA 4 units/kg or 8 units/kg, or placebo.

The Modified Ashworth Scale-Bohannon scores were significantly improved for patients receiving onabotulinumtoxinA 8 units/kg (-1.06) and 4 units/kg (-1.01) compared to placebo (-.80) (P <.05).

An open-label study for upper limb spasticity included 222 participants. This study focused on safety, with the primary outcome being the percentage of patients reporting at least one adverse event over the course of 60 weeks. The open-label trial for lower limb spasticity followed 350 participants and had the same primary outcome.

“The positive results for Botox for the treatment of pediatric upper and lower limb spasticity are promising as we look to address unmet and ongoing needs in children and adolescents," Kim said.