Introduction: Long-term efficacy of onabotulinumtoxinA (onabotA) in post-stroke lower limb spasticity (PSLLS) is not clearly established.
Hypothesis: OnabotA provides sustained efficacy in PSLLS.
Methods: A multicenter, phase 3, 12-week, double-blind (DB), placebo-controlled study of patients with ankle PSLLS (Modified Ashworth Scale [MAS] ≥3) was followed by an open-label (OL) extension, during which all patients received 1-3 treatment cycles (∼12-week intervals) of onabotA (≤400U). Endpoints: change from baseline in MAS and Clinical Global Impression of Change (CGI) physician rating, and percent of patients achieving passive and active goals (Goal Attainment Scale [GAS]) by physician and patient.
Results: 468 patients enrolled (onabotA, n=233; placebo, n=235); 447 (95.5%) completed the DB and 249 (53.2%) completed the OL phase at DB database lock. Significant improvement in MAS achieved with onabotA in DB was sustained in OL phase (Table). Significant improvements in CGI in DB continued to improve in OL phase. During OL phase, MAS ankle change from baseline and CGI by physician raw scores and proportions of responders were largest at week 6 and generally increased over 3 OL treatment cycles. With onabotA, GAS by patient improved (P=0.036), as did the proportion that progressed toward active (P=0.009) and passive (P=0.044) goal attainment by physician. The percentage of patients who met passive and active goals (GAS by physician≥0) after 1 onabotA treatment increased from 40% to 64% and 27% to 65%, respectively, after 4 treatments. Common DB treatment-related AEs (onabotA vs placebo): injection-site pain (1.7% vs 0.9%) and pain in extremity (0.4% vs 2.1%).
Conclusions: OnabotA was well-tolerated and produced improvements in MAS, CGI, and GAS during the DB phase that continued into the OL phase, demonstrating long-term benefits in patients with PSLLS.