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Objective:To demonstrate single abobotulinumtoxinA injection efficacy in lower limb vs placebo for adults with chronic hemiparesis and assess long-term safety and efficacy of repeated injections.Methods:In a multicenter, double-blind, randomized, placebo-controlled, single-cycle study followed by a 1-year open-label, multiple-cycle extension, adults ≥6 months after stroke/brain injury received one lower limb injection (abobotulinumtoxinA 1,000 U, abobotulinumtoxinA 1,500 U, placebo) followed by ≤4 open-label cycles (1,000, 1,500 U) at ≥12-week intervals. Efficacy measures included Modified Ashworth Scale (MAS) in gastrocnemius–soleus complex (GSC; double-blind primary endpoint), physician global assessment (PGA), and comfortable barefoot walking speed. Safety was the open-label primary endpoint.Results:After a single injection, mean (95% confidence interval) MAS GSC changes from baseline at week 4 (double-blind, n = 381) were as follows: −0.5 (−0.7 to −0.4) (placebo, n = 128), −0.6 (−0.8 to −0.5) (abobotulinumtoxinA 1,000 U, n = 125; p = 0.28 vs placebo), and −0.8 (−0.9 to −0.7) (abobotulinumtoxinA 1,500 U, n = 128; p = 0.009 vs placebo). Mean week 4 PGA scores were as follows: 0.7 (0.5, 0.9) (placebo), 0.9 (0.7, 1.1) (1,000 U; p = 0.067 vs placebo), and 0.9 (0.7, 1.1) (1,500 U; p = 0.067); walking speed was not significantly improved vs placebo. At cycle 4, week 4 (open-label), mean MAS GSC change reached −1.0. Incremental improvements in PGA and walking speed occurred across open-label cycles; by cycle 4, week 4, mean PGA was 1.9, and walking speed increased +25.3% (17.5, 33.2), with 16% of participants walking >0.8 m/s (associated with community mobility; 0% at baseline). Tolerability was good and consistent with the known abobotulinumtoxinA safety profile.Conclusions:In chronic hemiparesis, single abobotulinumtoxinA (Dysport Ipsen) administration reduced muscle tone. Repeated administration over a year was well-tolerated and improved walking speed and likelihood of achieving community ambulation.Clinicaltrial.gov identifiers:NCT01249404, NCT01251367.Classification of evidence:The double-blind phase of this study provides Class I evidence that for adults with chronic spastic hemiparesis, a single abobotulinumtoxinA injection reduces lower extremity muscle tone.

Introduction: The efficacy of single injections of abobotulinumtoxinA (Dysport) is established in adults with upper limb spasticity. In this study we assessed the effects of repeated injections of abobotulinumtoxinA over 1 year. Methods: Patients (n = 258, safety population) received 500 U, 1,000 U, or 1,500 U (1,500‐U dose included 500‐U shoulder injections) for up to 4 or 5 treatment cycles. Assessments included treatment‐emergent adverse events (TEAEs), muscle tone, passive and active range of motion (XV1, XA), angle of catch (XV3), Disability Assessment Scale (DAS) score, Modified Frenchay Scale (MFS) score, and Physician Global Assessment (PGA) score. Results: The incidence of TEAEs decreased across cycles. Muscle tone reduction and XV1 remained stable across cycles, whereas XV3 and XA continued to improve at the finger, wrist, and elbow flexors. DAS and PGA improved across cycles. MFS improved best with 1,500 U. Discussion: A favorable safety profile and continuous improvements in active movements and perceived and active function were associated with repeated abobotulinumtoxinA injections in upper limb muscles. Muscle Nerve 57: 245–254, 2018

III.

Naturally occurring botulinum toxin (BoNT) serotypes have different pharmacological features of therapeutic and aesthetic interest. This phase 1, double-blind, placebo-controlled study (EudraCT: 2016-002609-20) assessed safety, tolerability and pharmacodynamics (PD) of the first recombinant BoNT serotype E (rBoNT-E) versus abobotulinumtoxinA (Dysport®), administered to extensor digitorum brevis (EDB) of healthy males. Subjects were randomised 3:1 (n = 28) to single ascending rBoNT-E (0.04-3.6 ng) doses or placebo. A further 24 subjects received abobotulinumtoxinA (20, 40, or 70 U) or placebo. PD were assessed using compound muscle action potential (CMAP) amplitude. Demographics were similar between groups. All rBoNT-E doses were well tolerated (no severe treatment-emergent adverse events [TEAEs], serious adverse events, or treatment-related toxicities). Most TEAEs were mild/moderate and treatment-unrelated. rBoNT-E had a faster onset of action (days 1-2 post-injection), greater peak effect (> 90% CMAP inhibition), and shorter duration of effect at highest tested doses versus abobotulinumtoxinA (onset of action ≤7 days post-injection; 70% maximal CMAP inhibition). rBoNT-E duration of effect was 2-7 weeks versus > 26 weeks for abobotulinumtoxinA. Dose-dependent effects were observed for magnitude and duration of EDB CMAP inhibition, plateauing at 0.9 and 3.6 ng. rBoNT-E demonstrated a good safety profile and a PD profile that may address unmet therapeutic and aesthetic patient needs. manufactured with recombinant technology (rBoNT-E) using the host Escherichia coli and containing genes encoding the natural sequence of BoNT-E, has been identified as a drug candidate [5]. Prior pre-clinical research using recombinant technology has been performed in various BoNT serotypes [6]; however, rBoNT-E is the first to reach clinical trials. Faster onset of action and shorter duration of effect, as well as a quick time to peak activity, have been reported in animal studies of rBoNT-E in comparison with established BoNT-A products, including abobotulinumtoxinA (Dysport®) [7,8]. This is likely to be due to differences between the exact mechanisms of action for the two different BoNT serotypes.rBoNT-E and BoNT-A both bind to synaptic vesicle protein 2 (SV2) [7,8], while BoNT-A can bind to all three isoforms (SV2A, SV2B, and