Immunogenicity of DaxibotulinumtoxinA for Injection in Glabellar Lines.

Abstract

DaxibotulinumtoxinA-lanm for injection (DAXI), a novel botulinum toxin type A formulation, contains a purified 150-kD core neurotoxin (daxibotulinumtoxinA) and proprietary stabilizing peptide (RTP004), and is approved for glabellar line treatment. As with any biologic product, DAXI may potentially be immunogenic and elicit unwanted antibody formation, possibly resulting in partial or complete treatment failure. The immunogenicity of DAXI was assessed in two double-blind, placebo-controlled, single-dose studies and an open-label safety study of up to 3 repeat treatments. Of the 2737 evaluable subjects, none developed neutralizing antibodies to daxibotulinumtoxinA and 0.8% developed treatment-related non-neutralizing anti-daxibotulinumtoxinA-binding antibodies. Of evaluable subjects exposed to RTP004 with either DAXI or placebo, 1.3% developed treatment-related anti-RTP004-binding antibodies, which were mostly transient. No subject developed binding antibodies to both daxibotulinumtoxinA and RTP004. All subjects with treatment-related binding antibodies to daxibotulinumtoxinA or RTP004 achieved a clinical response (none or mild glabellar line severity) at Week 4 following each DAXI treatment cycle. The duration of clinical response was not different between treatment cycles when antibodies were detected versus when they were absent. Although the analysis population was small compared with the number of patients likely to receive repeated treatment in clinical practice, these results suggest that DAXI administration at the approved glabellar lines dose has low immunogenic potential and that non-neutralizing antibodies to daxibotulinumtoxinA or RTP004 occur infrequently and often transiently, and have no impact on clinical efficacy, safety, or duration of action. Real-world data encompassing larger numbers of patients is needed to substantiate these results.