This presentation will describe a comparative evaluation of a commercially available ELISA kit and a bespoke, ultra-sensitive electrochemiluminescence (ECL) pharmacodynamic assay used to quantify a protein expressed from an mRNA therapy that has an endogenous counterpart. The two assays were employed across different studies, leading to observed differences in sensitivity and downstream PK/PD modeling outcomes.
The talk will begin with an overview of the development and validation strategies for each assay, highlighting key performance characteristics, including sensitivity, selectivity, and precision. A concordance study was conducted to assess agreement between the two platforms, given the enhanced sensitivity of the ECL assay and its potential impact on data interpretation.
Special emphasis will be placed on the challenges associated with quantifying a protein that has an endogenous counterpart, including limitations of reference standards and assumptions of proportionality. The use of incurred sample reanalysis (ISR) as a tool to evaluate parallelism and biological relevance across assay formats will be discussed.
Finally, the presentation will explore how assay differences influenced modeling outcomes between studies and provide practical considerations for selecting, bridging, and interpreting bioanalytical assays in support of mRNA-based therapeutics.
Learning Objectives:
Describe key development and validation differences between a kit ELISA and a bespoke ultra-sensitive ECL assay.
Evaluate assay concordance and its impact on PK/PD modeling across studies.
Apply ISR-based approaches to assess parallelism for proteins with endogenous counterparts.
