VANCOUVER, British Columbia — Early intervention with onabotulinumtoxinA (Botox®) may be effective for adults who experience lower limb spasticity after a stroke, according to research presented at the 68th annual meeting of the American Academy of Neurology (AAN).
While onabotulinumtoxinA is approved by the US Food and Drug Administration (FDA) for the treatment of poststroke upper limb spasticity, its efficacy in poststroke lower limb spasticity (PSLLS) is still being investigated.
To study whether onabotulinumtoxinA would benefit patients with PSLLS, Atul T. Patel, MD, from the Kansas City Bone & Joint Clinic in Overland Park, Kansas, and colleagues conducted a multicenter, phase 3, placebo-controlled study. They enrolled 468 participants with PSLLS (Modified Ashworth Scale [MAS] score ≥3) of the ankle.
During the 12-week double-blind phase, the participants were randomly assigned either onabotulinumtoxinA (n=233; 300 U to mandatory muscles [gastrocnemius, soleus, tibialis posterior]; and ≤100 U to optional lower limb muscles [flexor digitorum longus, flexor hallucis longus, flexor digitorum brevis, extensor hallucis, rectus femoris]) or placebo (n=235).
The primary end point was the average of the MAS change from baseline scores at weeks 4 and 6; secondary end points were the average score of weeks 4 and 6 of the physician-assessed Clinical Global Impression of Change (CGI) and the physician-assessed Goal Attainment Scale (GAS; active and passive at weeks 8 and 12).
The researchers found that those patients receiving onabotulinumtoxinA had significant improvements compared with those receiving placebo in MAS (-0.81 vs -0.61; P=.01), CGI (0.86 vs 0.65; P=.01), and passive GAS scores (week 12, -0.6 vs -0.9; P=.042).
When stratified by the time of treatment initiation after stroke, (≤24 months, n=153; >24 months, n=315, post hoc), patients who were treated within 24 months following stroke experienced greater improvements (mean difference from baseline vs placebo) in MAS (- 0.31 vs – 0.17), CGI (0.49 vs 0.12), and passive GAS scores (week 12, 0.37 vs 0.26). Among participants treated within 24 following stroke, a greater proportion achieved at least 1-point improvement in active (week 12; P=.039) and passive (week 8; P=.023) GAS scores vs placebo.
The researchers found that onabotulinumtoxinA 300 to 400 U was well tolerated with no new safety findings.
“OnabotulinumtoxinA 300 to 400 U is effective in improving MAS, CGI, and GAS scores in patients with PSLLS with greater benefits among those who initiate treatment ≤24 months poststroke,” the researchers concluded.
The study was supported by Allergan.
Disclosures: A.T. Patel: Allergan, Merz, and Ipsen. A. Ward: Allergan and Ipsen. C. Geis: Allergan. C. Liu: Allergan. W.H. Jost: Allergan, Ipsen, and Merz. R. Dimitrova: Allergan.
Patel AT, Ward A, Geis C, Liu C, Jost WH, Dimitrova R. Impact of early intervention with onabotulinumtoxina treatment in adult patients with post-stroke lower limb spasticity. Presented at: The 68th Annual Meeting of the American Academy of Neurology. April 15-21, 2016; Vancouver, British Columbia, Canada. Presentation S31.006.