Pain Reduction in Adult Patients with Limb Spasticity Following a Single IncobotulinumtoxinA Injection: an Analysis of Pooled Data from Phase 2 and 3 Studies
Jorg Wissel1, Alexandre Camões-Barbosa2, Georg Comes3, Michael Althaus4, Astrid Scheschonka3, David Simpson5
1Vivantes Hospital Spandau, 2Centro Hospitalar Universitário de Lisboa Central, 3Merz Therapeutics, 4Merz Pharmaceuticals GmbH, 5Mount Sinai School of Medicine
Objective:
To assess pain relief in a large cohort of incobotulinumtoxinA-treated pts with spasticity-associated pain (SAP) using pooled data from mostly placebo-controlled phase 2/3 studies.
Background:
IncobotulinumtoxinA (incoA) has shown pain-relieving benefits in patients (pts) with limb spasticity in individual studies; data from large pt cohorts are lacking.
Design/Methods:
Pain severity was assessed with the Disability Assessment Scale (DAS; 0–3) in adults with upper limb SAP. A ≥1 point reduction in the DAS pain score from baseline [BL] to 4 weeks was defined as response. Between-treatment group response rates (overall and by BL pain severity – DAS mild, moderate, severe) and the proportion of pts with complete pain relief (DAS pain score=0) at 4 weeks after 1 injection of incoA (total dose ≤400U) or placebo were analyzed using χ2 test. Overall between-group response rate differences were analyzed using logistic regression (presented as odds ratio [OR] and 95% confidence interval [CI]).
Results:
542 (incoA: 413, placebo: 129) pts reported SAP at BL. At 4 weeks, a significantly higher proportion of incoA- vs placebo-treated pts achieved a response (52.1% vs 28.7%; p<0.0001). IncoA-treated pts were more likely to achieve pain response vs placebo-treated pts (OR 2.7 [95% CI:1.6–4.3]; p<0.0001). Irrespective of BL pain severity, significantly higher response rates were observed with incoA vs placebo at 4 weeks (p<0.02 all comparisons). Complete pain relief was achieved by significantly more incoA- vs placebo-treated pts at 4 weeks (26.9% vs 12.4%; p=0.0007).
Conclusions:
Pts receiving incoA vs placebo are significantly, by 2.7 times, more likely to achieve reduced upper limb SAP, irrespective of baseline pain severity, at 4 weeks post-injection thus supporting use of incoA in this setting.