The U.S. Food and Drug Administration (FDA) recently approved onabotulinumtoxinA (Botox, Allergan) to ease upper limb spasticity in children and adolescents aged 2 to 17 years. The Clinical Research Center at Marshfield Clinic Research Institute was one of 40 international sites that conducted the clinical trial.

Common causes of spasticity in children include cerebral palsy, traumatic brain injury, spinal cord injury and stroke.

Botox is the first neurotoxin to be approved in the U.S. to treat upper limb spasticity in pediatric patients.

Research Institute involvement

"Botox has been used routinely by most pediatric rehabilitation physicians as a significant component of spasticity treatment," said Jill Meilahn, D.O., pediatric physical medicine and rehabilitation specialist and lead investigator for the Research Institute on this study. "While there are many studies over the last two decades documenting these benefits, a systematic double-blinded placebo controlled study assessing the safety of Botox in pediatric patients with upper limb spasticity was not previously conducted. This study now verifies that Botox is a safe and useful tool in the treatment of pediatric upper limb spasticity."

Botox had previously been FDA-approved beginning in the 1970s for use on adults for various conditions such as blepharospasm, cervical dystonia, upper limb spasticity after stroke, chronic migraines and others.

"I already knew Botox would work to reduce spasticity because I've been using Botox injections for 30 years on pediatric patients," Dr. Meilahn said. "I am glad they completed a study specifically on children because it gives me and my patients more scientific knowledge on best techniques, dosing and safety." 

As an example, Dr. Meilahn was excited to find that Botox had few side effects. The clinical trial showed that the incidence of side effects was similar in the placebo group compared to the Botox group.

Dr. Meilahn is co-authoring a paper on the findings that will be submitted in the coming months. She will also be giving two presentations this fall about the research - one in September at the American Academy of Cerebral Palsy and Developmental Medicine and the other in November at the American Academy of Physical Medicine and Rehabilitation.

Dr. Meilahn worked with Sandy Freeman, research coordinator for the Clinical Research Center, on the project.

"I am appreciative of the Research Institute, Clinical Research Center and staff including Sandy and research pharmacist, Connie Folz, who made it possible to be a part of this notable research. I also had support of clinic staff, including sedation services and physical and occupational therapists, who had to follow the strict protocols of the study," Dr. Meilahn said.

The specifics

The FDA approved Botox for upper limb spasticity in children aged 2 years and older on the basis of data from two phase 3 safety and efficacy studies that enrolled more than 200 children. One study was a 12-week, double-blind study, and the other was an open-label extension study of up to five repeated doses of Botox over about 60 weeks.

The recommended dose per treatment session is 3 – 6 units/kg divided among affected muscles of the upper limb. The total dose for pediatric patients should not exceed 8 units/kg body weight, or 300 units, whichever is lower, in a 3-month period.

Treatment with Botox is not a replacement for existing physical therapy or other rehabilitation that may have been prescribed. All study participants received weekly physical or occupational therapy.

The FDA is reviewing an additional sBLA for the use of Botox to treat children with lower limb spasticity; a decision is expected in the fourth quarter of this year. Dr. Meilahn and her team also participated in that trial.