Evaluate botulinum toxin A (BoNT-A) reinjection intervals within an integrated rehabilitation management setting.

The ULIS-III study aims to describe the real-life management of upper-limb spasticity within an integrated approach, including repeat BoNT-A injection cycles. One way to understand the duration of BoNT-A benefit is to evaluate the time to reinjection, which is often tailored to patient needs.  

ULIS-3 (NCT02454803) was a prospective, international, multicenter, observational study that examined longitudinal outcomes in adult (≥18y) patients with upper-limb spasticity. A multivariate additive linear regression model was built to evaluate treatment intervals adjusting on multiple baseline and treatment covariates depending on significance (potential factors included toxin, age, sex, previously treated for upper-limb spasticity with BoNT, time from event onset to Cycle 1, distribution of spasticity, dominance of affected limb, indication of lower limb spasticity, duration of BoNT-A prior to study, systemic antispastic medications, injection guidance technique, mean indexed dose, any physiotherapy during the study and number of therapy visits).

Of the 1004 enrolled patients, 828 remained on the same BoNT-A product during the study and had their injection intervals assessed. Across the study, the mean ±SD injection interval (all BoNT-A products) was 213.1 ± 164.7 days; treatment intervals with abobotulinumtoxinA (222.8 ± 167.2 days) were numerically longer than onabotulinumtoxinA (204.4 ±173.6 days) and (166.9 ±105.1 days). After conducting multivariable linear regression analyses, statistically significant differences in the overall injection intervals between abobotulinumtoxinA vs. incobotulinumtoxinA (difference of 36.4 days, p=0.002) and abobotulinumtoxinA vs. onabotulinumtoxinA (difference of 18.1 days, p=0.03) remained.

These real-world injection data from a large, observational study support the clinical experience that there are clinical differences between BoNT-A products that should be taken into account when designing patient treatment plans.