Identity Testing of Biopharmaceuticals using Nano-Differential-Scanning-Fluorimetry

Identity (ID) testing is an integral part of the analytical control strategy of biopharmaceutical products confirming the ID of both drug substances (DS) before starting the fill-finish process as well as of the finished drug product (DP). Common methods for ID testing, including liquid chromatography-mass spectrometry and immunoassays, often involve time-intensive workflows and demanding data analysis, creating challenges and added complexity for routine quality control ID testing.

This study evaluated a novel ID testing approach using nano-scale differential scanning fluorimetry (nanoDSF), which measures intrinsic protein fluorescence during thermal unfolding. Multiple data analysis strategies were evaluated, including single-point, curve correlation, and squared Euclidean distance (ED²) analyses.

A panel of fifteen biopharmaceutical products was tested representing diverse molecular formats. Method performance was assessed using confusion matrices comparing samples to reference profiles. The ED² metric (threshold 0.006) demonstrated strongest performance, achieving 100% specificity and 99.7% sensitivity across the product panel excluding biosimilars.

The nanoDSF method's robustness and rapid turnaround time support its suitability as an ID test for facilities handling multiple products and diverse product types. The selected data analysis approach does not require generation of statistical models enabling simplified method validation and implementation in QC.