Stability assessment of Polatuzumab vedotin and Brentuximab vedotin using different analytical techniques

Antibody-drug conjugates (ADC) are considered to be fast-growing innovative biopharmaceuticals. The science used for conjugating potent cytotoxic payload to the targeted monoclonal antibody through a chemical linker has played a great value in the area of oncology treatment. In this study; Polatuzumab vedotin (POLA) and Brentuximab vedotin (SGN-35) were subjected to various stress conditions enclosing different pH, thermal stress, agitation, and successive cycles of freeze and thaw in order to produce potential degradation by-products and guarantee the appropriateness of the applied testing protocol. Different analytical techniques were established and validated to be used in the quantitation of the degraded products from different perspectives. The formation of ADC aggregates and fragments was monitored using SE-HPLC as well as dynamic light scattering (DLS). The drug antibody ratio (DAR) and ADC conjugation profile were determined using hydrophobic interaction chromatography (HIC-HPLC). In addition to performing a statistical interpretation of HIC-HPLC results by principal component analysis (PCA) to explicate the obtained data. Also, the quantity of the unconjugated toxic drug was quantified using RP-HPLC. Testing the binding activity of ADC to their target receptor ADC was conducted using ELISA. Results presented that used assay protocol had worked as a complementary design for characterization and stability assessment of the used ADC. Variances in the stability profile of both products were observed which could be attributed to the usage of different formulation buffers. This highlighted the importance of using multiple techniques for the assessment of the quality attributes of such sophisticated products. The analytical assay protocol should be used for the evaluation of the quality and stability of several ADC.