Evaluating the Effectiveness and Safety of AbobotulinumtoxinA in Pediatric Lower Limb Spasticity (PLLS)

Research Objectives: To assess the longitudinal attainment of patient-centered, function-related goal attainment scale (GAS) T-score after repeated abobotulinumtoxinA (aboBoNT-A) injections.

Design: Phase IV, prospective, observational study.

Setting: 28 US-based centers.

Participants: Patients aged 2–17 years with PLLS.

Interventions: AboBoNT-A injections over ≤30 months (≤10 cycles).

Main Outcome Measures: Assessment of cumulated GAS T-scores across all cycles to measure progress of therapy goals; scores of ≥50 reflect goal achievement.

Results: Of 210 patients, 77.6% (n=163) were previously treated with botulinum neurotoxin. Available Gross Motor Function Classification System (GMFCS) levels showed that 31.3% (n=61/195) of patients were non-ambulatory (GMFCS IV/V). Mean±SD cumulated GAS T-score was 51.1±9.3. Overall, 75.2% of patients achieved their primary goals. Across all cycles, the number of muscles injected ranged from 5.5±2.9‒7.0±3.7; the number of injection points ranged from 8.1±2.7‒9.9±5.7, with gastrocnemius injections being most common (85.7%). Injection guidance techniques were used in >70% of patients in Cycles 1‒6; electrostimulation was most frequent (>50%). In the safety population (N=242), 102 patients (42.1%) reported 392 treatment-emergent AEs, which were mostly mild to moderate. Overall, a total of 35 AEs in 15 patients (6.2%) were deemed treatment-related.

Conclusions: Overall, goals were achieved as or better than expected in the majority of patients. AboBoNT-A was well tolerated, with a low incidence of treatment-related AEs. These results confirm aboBoNT-A as an effective treatment option, with a positive risk-benefit profile.

Author(s) Disclosures: MG: Received consultancy fees/research support from Ipsen; ED: Received consultancy fees and/or research support from Allergan, Ipsen, Solstice, Merz; AT: Received consultancy fees/research support from Ipsen; AC: Received research support from Ipsen; SHE: Received consultancy fees from Biogen and Ipsen; FCG and JG: Employees of Ipsen.