July 9, 2020
The U.S. FDA has approved an expanded indication for Botox® (onabotulinumtoxinA), manufactured by Allergan. The product is now indicated to treat spasticity in patients who are at least two years of age, regardless of whether the condition affects the upper or lower limbs and is or is not caused by cerebral palsy (CP). Previously, the treatment of CP-caused lower limb spasticity was excluded from Botox’s spasticity indication.
Spasticity is a form of motor impairment caused by abnormal increases in muscle stiffness or tone. It is often the result of nerve damage caused by cerebral palsy, multiple sclerosis, stroke, spinal cord damage, brain trauma, or head trauma. Symptoms include rapid muscle contraction and severe, painful muscle spasms.
Botox’s expanded spasticity indication was granted based on a mutual agreement between Allergan and Ipsen Pharmaceuticals, the manufacturer of Dysport® (abobotulinumtoxinA), to waive orphan drug exclusivity rights that limited the spasticity indications of Botox and Dysport. Allergan waived its rights to orphan drug exclusivity for upper limb spasticity caused by CP, while Ipsen waived its rights to exclusivity for lower limb spasticity caused by CP.
Recommended dosing under the expanded indication is based on individual patient factors, including the patient’s age, affected muscles, severity of spasticity, the presence of local muscle weakness, and the patient’s response to previous treatment or adverse event history with botulinum toxin products like Botox. Botox is administered via intramuscular injection by a healthcare professional.
A black box warning cautions that all botulinum products, including Botox, carry a risk of distant spread of effects from the injection site. The spread of effects can produce symptoms consistent with botulinum toxin hours to weeks after injection and may lead to life-threatening difficulties with swallowing and breathing. The risk is believed to be greatest in children treated for spasticity, though adults may experience symptoms as well.
Known in part for its cosmetic uses, Botox is also FDA approved to treat strabismus, chronic migraines, overactive bladder, cervical dystonia, severe axillary hyperhidrosis, blepharospasm associated with dystonia, and urinary incontinence associated with a neurologic condition.