Evaluate the sensitivity to change of the Leg Activity Measure (LegA) following treatment of lower limb spasticity (LLS) with a single cycle of abobotulinumtoxinA (aboBoNT-A) and rehabilitation in an ambulatory population.

The LegA was developed as a patient/carer rated outcome measure of active and passive function in the paretic lower limb, particularly when associated with spasticity. However most prior experience with this outcome has been in a non-ambulatory population.  

AboLiSH (NCT04050527) is a prospective, longitudinal observational study. Eligible participants are aged ≥18y with unilateral LLS, able to take ≥5 steps with/without assistance, and for whom the decision has been made to inject aboBoNT-A. At baseline, participants set treatment goals related to LLS. Where possible, goal outcome is supported by standardized measurement using the LegA.

Of the 376 patients included in the interim Cycle 1 analysis, 278 had ≥1 assessment using the LegA. Part A assesses the patient’s ability to care for the affected leg (passive function); mean±SD scores reduced (improved) from 8.8±7.2 at baseline to 7.6±6.2 at end of cycle (mean [95%CI] change of -1.4 [-1.8, -0.9], n=261). Part B assesses the ability to independently complete activities using the affected leg (active function); mean±SD scores improved from 24.4±13.1 at baseline to 22.2±11.8 at end of cycle (mean [95%CI] change of -2.6 [-3.4, -1.9], n=261). Part C assesses the impact of spasticity on quality of life; mean±SD scores improved from 15.8±7.2 at baseline to 13.7±6.5 at end of cycle (mean [95%CI] change of -2.3 [-2.8, -1.7], n=258).

Findings from this observational study of aboBoNT-A in the routine management of LLS confirm the responsiveness of the LegA for spasticity intervention and further support use in the ambulatory population. For this cohort, improvements in active function and impact on life were ≥2 absolute points indicating clinically relevant improvement.