Objective: This study was conducted to assess in vivo and in vitro activity of 50 U, 100 U, and 200 U vials of incobotulinumtoxinA (Merz, Inc.) in relation to 100 U onabotulinumtoxinA (Allergan plc) product.

Background: The introduction of incobotulinumtoxinA to the market has led to an ongoing clinical controversy on whether incobotulinumtoxinA is interchangeable with onabotulinumtoxinA.

Methods: 50 U, 100 U, and 200 U vials of incobotulinumtoxinA and 100 U onabotulinumtoxinA were diluted and tested at equal botulinum toxin type A product label activity units in 4 distinct assays: rat compound muscle action potential (CMAP), mouse digit abduction score (DAS), cell-based potency assay (CBPA), and light chain activity (LCA) assay.

Results: Multiple orthogonal assays demonstrated that the biological activity of incobotulinumtoxinA Units is less than onabotulinumtoxinA Units. Higher doses of incobotulinumtoxinA were required to cause 50% inhibition (ID50) in the CMAP assay, demonstrating that onabotulinumtoxinA displays greater biological activity compared to incobotulinumtoxinA. Superior biological activity was displayed by onabotulinumtoxinA in the DAS assay, which demonstrated statistical differences between onabotulinumtoxinA and incobotulinumtoxinA. CMAP and DAS data were corroborated by CBPA data. Additionally, greater light chain activity was displayed by 100 U onabotulinumtoxinA when evaluated against 50 U, 100 U, and 200 U incobotulinumtoxinA. Light chain activities of 50 U, 100 U, and 200 U products were approximately 50% of predicted values. No atypical cleavage products were observed when testing any of the incobotulinumtoxinA products, which differs from previous 50 U and 100 U results, and suggests that changes have been made to the product.

Conclusions: Data from 4 different assays establish that, on a unit for unit basis, onabotulinumtoxinA displays greater biological activity than incobotulinumtoxinA confirming that units of onabotulinumtoxinA and incobotulinumtoxinA are not interchangeable. Data presented here emphasize that non-interchangeability and product-specific potency must be considered when dosing patients.

This abstract was previously submitted to the Association of Academic Physiatrists 2017 Annual Meeting, Las Vegas, NV, February 7-11, 2017.

« Back to 2017 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/onabotulinumtoxin-a-botox-displays-superior-activity-to-incobotulinumtoxina-xeomin-in-multiple-in-vitro-and-in-vivo-assays/