Pharmaceutical company Allergan plc (NYSE:AGN) reported on Friday the receipt of approval from the US Food and Drug Administration (FDA) for its supplemental biologics application (sBLA) for BOTOX for treating paediatric patients two to 17 years of age with upper limb spasticity under its six-month priority review.

Additionally, the US FDA is reviewing a sBLA for the use of BOTOX to treat paediatric patients with lower limb spasticity, with a decision expected in the fourth quarter of 2019.

Damage to the brain and spine can result in spasticity, which is often observed as muscle tightness and stiffness in the upper and lower limbs. Common causes of spasticity include cerebral palsy, traumatic brain injury, multiple sclerosis and spinal cord injury, as well as stroke.

This US FDA approval is based on data from the company's two Phase 3 studies that is evaluating the safety and efficacy of BOTOX (onabotulinumtoxinA) in over 200 paediatric patients with upper limb spasticity. 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 three units per kilogram to six units per kilogram divided among affected muscles of the upper limb. The total dose in paediatric patients should not exceed eight units per kilogram body weight or 300 units, whichever is lower, in a three month interval, concluded the company .