OnabotulinumtoxinA Improves Pain in Patients With Post-Stroke Spasticity: Findings From a Randomized, Double-Blind, Placebo-Controlled Trial

CONTEXT: Patients with post-stroke spasticity (PSS) commonly experience pain in affected limbs, which may impact quality of life. OBJECTIVES: To assess onabotulinumtoxinA for pain in patients with PSS from the BOTOX(®) Economic Spasticity Trial, a multicenter, randomized, double-blind, placebo-controlled trial. METHODS: Patients with PSS (N = 273) were randomized to 22- to 34-week double-blind treatment with onabotulinumtoxinA + standard care (SC) or placebo injection + SC and were eligible to receive open-label onabotulinumtoxinA up to 52 weeks. Assessments included change from baseline on the 11-point pain numeric rating scale, proportion of patients with baseline pain ≥4 achieving ≥30% and ≥50% improvement in pain, and pain interference with work at Week 12, end of double-blind treatment, and Week 52. RESULTS: At baseline, most patients (74.3%) experienced pain and 47.4% had pain ≥4 (pain subgroup). Mean pain reduction from baseline at Week 12 was significantly greater with onabotulinumtoxinA + SC (-0.77, 95% CI -1.14 to -0.40) than placebo + SC (-0.13, 95% CI -0.51 to 0.24; P < 0.05). Higher proportions of patients in the pain subgroup achieved ≥30% and ≥50% reductions in pain at Week 12 with onabotulinumtoxinA + SC (53.7% and 37.0%, respectively) compared with placebo (28.8% and 18.6%, respectively; P < 0.05). Reductions in pain were sustained through Week 52. Compared with placebo + SC, onabotulinumtoxinA consistently reduced pain interference with work. CONCLUSION: This is the first randomized, placebo-controlled trial demonstrating statistically significant and clinically meaningful reductions in pain and pain interference with work with onabotulinumtoxinA in patients with PSS.