Development and validation of LC-MS/MS methods for the pharmacokinetic assessment of the PROTACs bavdeglutamide (ARV-110) and vepdegestrant (ARV-471)

Targeted protein degradation using proteolysis targeting chimeras (PROTACs) represents a promising pharmacological approach to address the challenges of “druggability” in intracellular targets. However, despite their beneficial pharmacological properties, these compounds exhibit complex molecular characteristics that limit their oral bioavailability. To facilitate the clinical application of PROTACs, it is crucial to develop sensitive bioanalytical methods capable of evaluating their absorption, bioavailability, and disposition following oral administration. In this study, we developed and validated two highly sensitive LC-MS/MS methods (LLOQ = 0.5 ng/mL) for quantifying bavdeglutamide (ARV-110) and vepdegestrant (ARV-471) in rat plasma. Plasma samples underwent protein precipitation and were analyzed using a C18 column with a gradient of acetonitrile and water containing 0.1% formic acid. Selected reaction monitoring in positive ESI mode was employed for the quantification of ARV-110 and ARV-471. Both methods demonstrated linearity, accuracy, precision, and acceptable matrix effects and carry-over. The compounds showed high stability in plasma during long-term storage at -20 °C for seven weeks, after three freeze-thaw cycles, for up to 20 minutes at room temperature, and when stored as extracts in the autosampler. The plasma concentration-time profiles after intravenous and intraduodenal single-dose bolus administrations in rats were successfully quantified at clinically relevant doses per body weight. The bioanalytical assays presented here provide a robust platform for a wide range of in vivo studies aimed at elucidating the oral absorption, bioavailability, and disposition of PROTACs.