An Evaluation of Neutralizing Antibody Induction During Treatment of Glabellar Lines with a New US Formulation of Botulinum Neurotoxin Type A

At the dose and treatment interval used in the correction of glabellar lines, induction of neutralizing antibodies to BoNTA-ABO was not observed. None of the five samples that initially gave positive results in a RIPA-C assay were positive when further evaluated using the MPA. Clinically, RIPA-C-positive status did not correlate with any reduction in efficacy or an altered safety profile, although the small numbers prevent definitive conclusions. These data suggest that the five RIPA-C-positive samples represented false positives.