Switching from onabotulinumtoxinA to abobotulinumtoxinA in children with cerebral palsy treated for spasticity: A retrospective safety evaluation

Abstract

Botulinum neurotoxin-A (BoNT-A) is an important treatment in the management of hypertonia in children with cerebral palsy (CP). To date, there are no controlled head-to-head clinical trials comparing the efficacy and safety of different BoNT-A formulations in CP. The main aims of this study were to explore whether switching from onabotulinumtoxinA (OnaBoNT-A) to abobotulinumtoxinA (AboBoNT-A) is safe and whether therapeutic efficacy is maintained. This retrospective observational study included 118 children with CP (mean age: 81.4 ± 38.9 months) who had switched from OnaBoNT-A to AboBoNT-A injections into their lower extremities due to a change in hospital policy. Analysis was limited to the final OnaBoNT-A treatment cycle (TC) prior to switch, and the first AboBoNT-A TC following switch. The primary objective was to document safety in children switched from OnaBoNT-A to AboBoNT-A. Efficacy endpoints included muscle tone, spasticity, and gait function based on Modified Ashworth Scale (MAS), Tardieu Scale (TS), and Observational Gait Scale (OGS) scores. A sub-analysis was performed to investigate the time to retreatment for patients attending their follow-up visits for efficacy assessments ( n = 52). Treatment emergent adverse events were recorded in 41 (34.7%) and 31 (26.3%) patients during the OnaBoNT-A and AboBoNT-A TCs, respectively. Treatment related adverse events were reported in 5 patients in OnaBoNT-A TC versus 7 in AboBoNT-A ( P = 0.774). Treatment efficacy, (4–6 weeks post-treatment) was found to be similar in the OnaBoNT-A and AboBoNT-A TCs for all variables (MAS, TS, OGS). The sub-analysis of 52 patients revealed a significantly longer retreatment interval with AboBoNT-A (27.6 ± 11.8 weeks) versus OnaBoNT-A (23.3 ± 8.7 weeks) ( P = 0.004). In children with CP, switching from OnaBoNT-A to AboBoNT-A was safe and efficacy was maintained. In a subgroup analysis AboBoNT-A appeared to have a longer retreatment interval than OnaBoNT-A.