# Evaluation of a Cell-Based Potency Assay for Detection of the Potency of TrenibotulinumtoxinE® (TrenibotE)

## TL;DR

This study evaluates a new cell-based test to measure the potency of a botulinum toxin drug, showing it is accurate and reliable.

## Contribution

A new cell-based potency assay for BoNT/E was developed and validated as an alternative to traditional methods.

## Key findings

- The CBPA demonstrated 98% accuracy and 6.3% intermediate precision.
- The assay met all acceptance criteria for linearity, repeatability, and precision.

## Abstract

(1) Background: As an innovative drug derived from botulinum neurotoxin serotype E, TrenibotulinumtoxinE® demonstrates a rapid onset and shorter effect. Due to concerns regarding specificity, test throughput, and animal welfare, a new cell-based potency assay (CBPA) method was developed for BoNT/E drug substance and drug product; independent evaluation of this new CBPA was required. (2) Methods: The CBPA for BoNT/E is a quantitative assay that measures the accumulated cleaved SNAP25180 in human neuroblastoma cells. It involves sequential culturing, differentiation of cells, and then treatment with drug products. Data were analyzed using a quadratic parallel model via statistical software. Linearity was determined using five effective concentration levels. Key assay parameters including accuracy, linearity, repeatability, intermediate precision and range were evaluated. (3) Results: The overall assay’s accuracy was 98%, and the intermediate precision was 6.3%. The coefficient of determination (R2) and slope were determined as 0.963 and 0.942, respectively. The root mean squared error (RMSE) was 0.057, and the intercept was 0.032 for the combined data. The repeatability was 2.4%, which is well within the acceptance criterion of ≤8%. (4) Conclusions: The evaluation was carried out within a single laboratory under controlled conditions; the new CBPA meets all acceptance criteria and can be used for BoNT/E potency determination.