Duration of effect of abobotulinumtoxinA (Dysport®) in adult patients with lower limb spasticity post-stroke or traumatic brain injury

Abstract

Few studies have assessed the treatment interval during repeated injections of botulinum toxin. In a double-blind (DB), single-treatment study followed by a long-term open-label (OL) extension study, abobotulinumtoxinA (aboBoNT-A, Dysport ® ) was efficacious and did not generate unexpected safety findings (Esquenazi et al. Am Acad Phys Med Rehabil 2016). This additional analysis reports the retreatment intervals for the lower limb in hemiparetic adults after repeated injections of aboBoNT-A. Phase III, international, multicentre, double-blind (DB), single-treatment study of aboBoNT-A in the hemiparetic lower limb, followed by a long-term open-label (OL) extension study with a maximum of 4 additional treatment cycles over a maximum of 18 months. Retreatment was per investigator's clinical judgement and possible at weeks 12, 16, 20, and 24. Among the subjects who received aboBoNT-A in the DB study and were treated in cycle 1 of the OL extension, 20% were re-injected at week 16 or later (10% at week 16, 5% at week 20, 5% at week 24 or later). For those who received a second cycle of treatment in the OL phase, 32% of subjects were re-injected at week 16 or later (17% at week 16, 9% at week 20, 7% at week 24). For those who received a third cycle of treatment in the OL phase, 15% of subjects were re-injected at week 16 or later. These data demonstrate the long duration of effect of aboBoNT-A in the spastic lower limb with 15–32% of subjects re-injected at week 16 or later across repeated cycles. A long duration of effect leading to a longer interval between injections may reduce the burden associated with frequency of injections for patients and their caregiver/families. This also highlights the need for a tailored approach in the treatment of the lower limb in hemiparesis.