Quantification using HPLC- DAD of targeted maytainsinoid: a new approach for pre-clinical studies

A novel antibody targeting tumour microenvironment has shown a potent and durable antitumor activity in preclinical models[1, 2 3]. This antibody was conjugated to a potent cytotoxic drug, obtaining an antibody drug conjugates (ADC), a new approach for drug delivery system. The novelty of this research is based on the possibility to follow the drug (DM4) and its main metabolite (S-Me-DM4) using a common instrumentation as HPLC coupled with DAD [4]. The method was fully validated in plasma, meanwhile the subsequent step was the validation in tissue sample. A liquidliquid extraction was used to extract both compounds into organic solvents, in order to avoid overlapping with interferences. In this study, pharmacokinetics and targeting potential were evaluated, using lung, kidney, liver and tumour of mice in various time points. The method was validated according to ICH guidelines, achieving high sensitivity, precision, and reproducibility, with applications across multiple preclinical models. This represents the first reported application of an HPLC method for dualanalyte detection of DM4 and its metabolite in ex vivo models.