ABSTRACT Introduction Erdafitinib is a pan‐FGFR tyrosine inhibitor approved for urothelial carcinoma, with growing interest in its broader anticancer applications. Accurate quantification in preclinical models is essential for understanding pharmacokinetics and optimizing therapeutic use. Developing a sensitive, economical bioanalytical method ensures reliable drug monitoring, supporting translational research and regulatory compliance in oncology drug development. Methods Rat plasma samples were processed by protein precipitation, and analytes were separated on a reverse‐phase column using a gradient mobile phase. Detection employed LC‐MS/MS in positive ionization mode with multiple reaction monitoring (MRM), monitoring m / z 447.1 → 362.1 for erdafitinib and m / z 515.2 → 276.0 for internal standard. The total run time was 2.0 min. Results The method demonstrated excellent linearity across 1.0–1000 ng/mL with a lower limit of quantification of 1.0 ng/mL. Precision was < 12% and accuracy within 100% ± 6% across the calibration range. The assay was validated according to US FDA M10 guidelines and successfully applied to pharmacokinetic studies in Sprague Dawley rats, enabling reliable plasma concentration profiling of erdafitinib. Conclusions This validated LC‐MS/MS method provides a rapid, sensitive, and cost‐effective approach for erdafitinib quantification in preclinical plasma samples. Its application to pharmacokinetic studies supports drug development by enabling accurate assessment of exposure and disposition, thereby advancing pharmacological understanding and facilitating translation to clinical oncology research.
Boggavarapu et al. (Tue,) studied this question.