ABP-450 (prabotulinumtoxinA) - (BOTOX biosimilar)

August 19, 2026: AEON Biopharma (NYSE: AEON) reported expanded analytical comparability data for ABP-450, its biosimilar candidate to BOTOX (onabotulinumtoxinA) for therapeutic use under the FDA 351(k) pathway. Expanded primary structure testing increased active botulinum neurotoxin sequence coverage to 98% from about 93% previously reported, with 100% amino acid identity across all analyzed regions, including the light-chain/heavy-chain activation junction.

Preliminary disulfide bond characterization found the same interchain disulfide bond, C430-C454, in ABP-450 and BOTOX across all tested lots; this disulfide-linked form represented about 99% of total species in each product. AEON said these findings support molecular similarity and are consistent with previously reported highly similar potency.

The expanded primary structure analysis was performed across six drug product samples spanning both products. AEON also referenced March 2026 disclosure of a January 2026 FDA Biosimilar Biological Product Development (BPD) Type 2a meeting, where the FDA said the company’s analytical methodologies appeared reasonable for advancement toward a comprehensive analytical similarity package.

Next catalyst: AEON expects feedback from a planned FDA BPD Type 2b interaction in the second half of 2026, which is intended to inform the next development phase, including clinical pharmacology and comparative clinical study requirements.