Efficacy of incobotulinumtoxin a in treatment of lower-limb spasticity, including pes equinovarus, in adults

Abstract

The TOWER study ( NCT01603459 ) previously demonstrated that escalating doses of incobotulinumtoxinA (400–≤800 U) in patients with upper- (UL) and lower-limb (LL) spasticity due to stroke or other cerebral causes increased treatment efficacy without compromising safety or tolerability (Wissel, Neurology 2017). This post-hoc analysis assessed the efficacy of incobotulinumtoxinA for LL spasticity, including pes equinovarus. Patients received treatment with escalating total incobotulinumtoxinA doses on the same body side during three injection cycles (ICs) (400 U, 600 U and 600–800 U, respectively; maximum 600 U per limb; optional pes equinovarus, planned dose range 100–400 U). Outcomes included change from IC baseline to 4 weeks post-injection in Ashworth Scale (AS) for the ankle joint (in patients treated for pes equinovarus or not) and LL resistance to passive movement scale (REPAS) scores (in patients treated in the LL [with/without UL treatment], or UL only). In total, 155 patients were enrolled. In IC1, IC2 and IC3, respectively, 109, 137 and 137 patients received LL treatment with mean (standard deviation [SD]) total limb doses of incobotulinumtoxinA: 191.7 (97.6), 254.0 (111.6) and 320.9 (127.6) U. Pes equinovarus was treated in 88, 117 and 122 of these patients. The mean (SD) improvement in ankle joint AS score at 4 weeks post-injection was –0.66 (0.77), –0.70 (0.82) and –0.82 (0.77) in patients treated for pes equinovarus, and –0.21 (0.64), –0.38 (0.85) and –0.61 (0.70) in patients who were not, with a significant difference between the groups in IC1 ( P = 0.0006). For all ICs, the mean improvement in REPAS LL scores 4 weeks post-injection was greater in patients who were treated in the LL than in patients treated in the UL only, with significant differences between groups in IC1 ( P < 0.0001) and IC2 ( P = 0.0043). Results suggest that incobotulinumtoxinA is effective for treating LL spasticity, including pes equinovarus.