Introduction: The therapeutic impact of botulinum toxin type A (BoNT-A) as first-line treatment for adult focal spasticity is well established across numerous therapeutic guidelines. However, relatively little real-world evidence exists to inform clinician decision-making when considering switching patients between BoNT-A products. This 5-year retrospective study aims to illustrate the safe transitioning of patients from onabotulinumtoxinA (ONA) to abobotulinumtoxinA (ABO) therapy in US centers that have considerable experience with BoNT-A usage in adults with spasticity.
Methods: Chart data from patients with upper limb spasticity (ULS), lower limb spasticity (LLS), or upper and lower limb spasticity (ULS+LLS) aged >18 years were collected from three US-based treatment centers. Eligible patients had >2 ONA treatment cycles before switching to ABO from September 2015 to September 2020; they were followed for three more ABO treatment cycles.
Results: A total of 88 patients (mean±SD age 44.9±19.6 years, 62.5% male) switched from ONA to ABO; in 84 (95.5%) patients, the switch was due to “medical need/effectiveness not achieved.” Spasticity etiologies included stroke (25.0%), traumatic brain injury (13.6%), spinal cord injury (2.3%), adults with cerebral palsy (42.0%), multiple sclerosis (9.1%), and other etiology (8.0%). Fifty-one patients (58.0%) had bilateral spasticity, with a mean 5.0±2.2 muscles injected at each visit over the 5-injection-cycle treatment period. Across the 2 initial cycles prior to the switch, mean doses of ONA were 425.0±179.0 units (U), 477.1±132.8 U, and 454.2±56.0 U for ULS, LLS, and ULS+LLS, respectively; following the switch, mean ABO doses across three treatment cycles were 1005.1±439.2 U, 1006.2±334.2 U, and 1203.2±325.7 U, respectively. No adverse events (AEs) were reported following conversion.
Conclusions: In this real-world study, patients with ULS, LLS, or ULS+LLS were switched from ONA to ABO and continued for at least three treatment cycles without any reported AEs. Mean doses of both ONA and ABO were generally aligned with the upper ranges of their respective dosing guidelines. Further randomized controlled studies evaluating the efficacy and safety of ONA vs ABO are warranted. Funding; Ipsen
Way N, Dabrowski E, Paulin M, Taylor M, Madden J, Mann A, et al. Switching adult patients with spasticity from onabotulinumtoxinA to abobotulinumtoxinA: a real-world data analysis across three US-based treatment centers. Toxicon. 2022 Jul;214(Suppl 1):S71.