Immunogenicity Associated with Aesthetic Botulinumtoxin A: A Survey of Asia-Pacific Physicians' Experiences and...

Most botulinum toxin A (BoNT/A) products contain unnecessary bacterial components that increase the risk of developing neutralizing antibodies (nAbs). Reports of secondary nonresponse and treatment failures (STF) due to nAbs have accompanied a surge in new BoNT/A products.

To formulate recommendations on managing toxin resistance, we reviewed the evidence on BoNT/A-associated immunogenicity and evaluated Asian physicians' current BoNT/A practices, knowledge, and real-world experiences, as provided by survey outcomes conducted with 128 Asian experts (regular botulinum toxin injectors).

Most doctors believe STF occurs, some patients exhibit partial symptoms, and impurities (eg, complexing proteins) in BoNT/A preparations risk STF. Bioassays that distinguish non-nAbs from nAbs that hinder toxin function remain unavailable to most doctors, though most would perform testing if given the option. Doctors in the Asia-Pacific region have differing strategies for managing STF, depending on the availability of alternatives or tests. They recommended switching to a highly-purified formulation free of complexing proteins and other impurities to lower the risk of immunogenicity, or offering treatment holidays of 2 -2.5 years. They suggested restarting treatment with the same highly purified formulation, especially for repeated treatments, large-dose injections, and younger patients who will accumulate higher lifetime doses, so as to minimize immunogenic risks and preserve long-term treatment outcomes. Importantly, doctors should always initiate patients on pure formulations rather than switching to these only after resistance develops.

Choosing highly purified BoNT/A products at treatment initiation enhances long-term efficacy and patient satisfaction while minimizing the risk of immune activation and nAb formation.