Efficacy and tolerability of a botulinum toxin type A free of complexing proteins (NT 201) compared with commercially available botulinum toxin type A (BOTOX®) in healthy volunteers

Purpose: This randomized controlled trial was performed to compare the novel botulinum toxin type A free of complexing proteins (NT 201) with the marketed preparation BOTOX(R) regarding efficacy and tolerability. Methods: Fourteen healthy volunteers received a single intramuscular injection into the extensor digitorum brevis (EDB) muscle of either 4 units NT 201, or 4 units of BOTOX(R) randomised by foot. Compound muscle action potential (CMAP) measurements were recorded for up to 90 days after injection. Results: Both drugs produced a maximum decline between Day 7 and Day 14. At Day 90, administration of both drugs resulted in approximately a 40% CMAP decline as compared to baseline. Duration of paralytic effect was comparable in both groups, at all response thresholds tested. Both drugs were well tolerated. Conclusion: The effects of small amounts of NT 201 and BOTOX(R) injected into the EDB muscle are comparable in terms of efficacy, time to onset of action, duration of action, and tolerability.