Efficacy and safety of abobotulinumtoxinA for upper limb spasticity in children with cerebral palsy: a randomized repeat-treatment study.

No true placebo group was used; the 2U/kg group was an active low-dose control assumed to be subtherapeutic, so some pharmacological effect in the control group cannot be excluded. Physicians and families knew all children would receive different doses of abobotulinumtoxinA, which may have influenced expectations and outcomes. All children continued existing physiotherapy or occupational therapy and completed a personalized home exercise therapy program, so the effects of therapy cannot be separated from the effects of abobotulinumtoxinA. The trial randomized children to fixed doses regardless of individual presentation, so it does not answer how clinicians should tailor dose to function, weakness, or motor control. The primary outcome was muscle tone, not function; global response, goal attainment, hand use, and range of motion did not show significant differences between doses. Children with fixed contracture, dystonic or choreoathetoid movements, aspiration or swallowing problems, recent surgery, phenol or alcohol injection, recent botulinum toxin treatment, or recent baclofen were excluded, so results may not apply to those groups. Assessments such as the Assisting Hand Assessment were limited to certified centers and small subgroups, and the study did not use the Manual Ability Classification System. The home exercise program had intensive study support and high reported compliance, so real-world families may not maintain the same intensity.

The study was sponsored by Ipsen. Randomization lists were created by a sponsor statistician. Several authors were investigators in Ipsen-sponsored clinical trials and received payments, consultancy fees, speaking fees, research support, or educational grants from Ipsen, Allergan, Merz, and Kashiv Pharma.

Do not read this as showing that higher abobotulinumtoxinA doses improve function more than the low dose. The dose difference was significant for muscle tone, not for global response, goal attainment, hand use, or range of motion, and all groups received abobotulinumtoxinA plus home exercises and ongoing therapy, so the contribution of any single component cannot be separated.