1000 Section - Impact of regional differences in use of injection guidance on goal attainment following repeat abobotulinumtoxinA injections: Subgroup analysis of the AboLiSh observational study

Objectives : Previously reported data showed that patients with leg spasticity who received abobotulinumtoxinA injections using instrumented injection guidance techniques (electromyography, electrostimulation, or ultrasound) at baseline were significantly more likely to reach their treatment goals compared to those treated without such guidance (odds ratio: 1.9 [95%CI 1.1, 3.1], p=0.02).

Design: Post-hoc analysis of the 16-month AboLiSh observational study (NCT04050527) exploring the effectiveness of abobotulinumtoxinA for leg spasticity. Subgroups were defined according to region – Eastern Europe and Central Asia [EECA] [n=136], Europe (n=132), and North America (n=89) – and analyzed separately for the primary effectiveness endpoint (cumulative GAS-leg T score) at Cycle 1 and across all cycles. We also evaluated the use of injection guidance at Cycle 1 per region.

Results: The use of instrumented injection guidance during Cycle 1 varied considerably across the three regions: 95.6% in EECA, 84.8% in Europe, and 52.8% in North America. Goal attainment at Cycle 1 was higher in the EECA subgroup, with a mean GAS-leg T score of 51.2 [95%CI: 49.8, 52.7], compared to the European subgroup of 49.2 [47.5, 50.8], which in turn outperformed the North American subgroup of 44.9 [42.7, 47.2]. Results for EECA and Europe were better than for North America (p< 0.0001 and p=0.003, respectively). The proportion of Cycle 1 responders (GAS T score ≥50 at end of Cycle 1) was highest in EECA (84.8%), followed by Europe (70.5%) then North America (50.6%). Evaluation of GAS T scores across all cycles indicated a similar pattern of better goal attainment with increasing use of instrumental injection guidance.

Conclusion: Regional analyses reinforce the overall study findings, demonstrating that goal attainment was higher among patients who received injection guidance compared to those who did not. Educational efforts to increase the use of guidance techniques to accurately target the affected muscles are needed to improve patient outcomes.