The U.S. Food and Drug Administration approved an expanded use of Allergan PLC's blockbuster drug Botox to treat children with lower limb spasticity, a type of muscle disorder.
Spasticity is a neurological condition that causes the muscles to continuously contract, leading to muscle stiffness and tightness in the upper and lower limbs that can interfere with movement.
The Irish pharmaceutical giant said the approval includes patients two to 17 years of age with lower limb spasticity but excludes lower limb spasticity caused by cerebral palsy — a type of muscle disorder that is caused by damage to an immature brain as it develops. The exclusion is due to marketing exclusivity by another company.
The FDA approval was backed by data from a phase 3 study, which included more than 300 patients aged two to 17 years old with lower limb spasticity. Some patients also had cerebral palsy, the company said.
Botox was approved by the FDA in June to treat children with upper limb spasticity. Allergan had submitted two supplemental biologics license applications to the U.S. regulator in March seeking approval for the drug in these indications.
Botox, Allergan's top-selling product, is approved in the U.S. for both upper and lower limb spasticity in adults 18 years old and above.
The drug is more commonly known as a cosmetic product, generating $3.58 billion in sales for Allergan in 2018. The company is being acquired by AbbVie Inc. in an $84.2 billion deal.