Safety and pharmacodynamics of a novel recombinant botulinum toxin E (rBoNT-E): Results of a phase 1 study in healthy male subjects compared with abobotulinumtoxinA (Dysport®)

Abstract

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

Split luciferase-based assay to detect botulinum neurotoxins using human motor neurons derived from induced pluripotent stem cell.

“…This does not t with previous experiments done on primary rodent cells [31] that indicated that BoNT/A was 30 times more potent than BoNT/E. But our ndings match with the observations from the rst clinical trial in human (phase one study) in which it was shown that BoNT/E potency is at least equivalent or even greater compare to toxin A [24]. These observations underline the translational value of a human cellular model.…”

Mechanism of Ganglioside Receptor Recognition by Botulinum Neurotoxin Serotype E

“…In particular, BoNT/A is known for its long-lasting clinical response (3–4 months). More recently, serotype E has been investigated in clinical trials [ 11 , 12 ], since its distinct pharmacological profile may represent an interesting therapeutic alternative for applications where a faster onset and shorter duration of effect is beneficial [ 13 ].…”

FDA Approvals and Consensus Guidelines for Botulinum Toxins in the Treatment of Dystonia

“…In the rBoNT-E group, time to onset ranged from 1-2 days compared to 1-7 days for the AboBoNT-A group. The maximum effect for the rBoNT-E group was 1 week and the effect lasted from 10 to 50 days depending on the dose injected [59]. This shorter acting toxin may be useful given the rapid onset of action and shortened duration of effects in novel clinical applications and approaches to dystonia management.…”