A Comprehensive Development and Validation of a Stability‐Indicating High‐Performance Liquid Chromatographic Method for Adagrasib Drug Substance With Degradation Product Characterization by Liquid Chromatography‐Tandem Mass Spectrophotometry

ABSTRACT Adagrasib (MRTX849), developed by Mirati Therapeutics, is a Kirsten rat sarcoma viral oncogene homolog, glycine‐to‐cysteine mutation (KRAS G12C) inhibitor approved by the Food and Drug Administration in December 2022 for the treatment of adult patients with KRAS G12C‐mutated locally advanced or metastatic non‐small‐cell lung cancer (NSCLC) who have received at least one prior systemic therapy. To address the critical need for precise and robust analytical methods for the quantification and characterization of Adagrasib and its impurities, this study presents the development and validation of a highly selective and sensitive high‐performance liquid chromatography (HPLC) method tailored for the analysis of drug substance. The method was systematically optimized through extensive trials with various column chemistries and mobile‐phase compositions. The optimized conditions employed a mobile phase comprising acetonitrile, methanol, and 0.1% triethylamine (TEA) buffer (pH adjusted to 2.5 using formic acid) in a 20:30:50 ratio, ensuring baseline resolution, stability, and reproducibility. Validation, conducted per ICH Q2 guidelines (International Council for Harmonization), demonstrated the method's excellent accuracy, precision, linearity, specificity, and robustness. The method exhibited low relative standard deviation (%RSD) values and high recovery rates, confirming precision and accuracy for Adagrasib and its impurities. Forced degradation studies under acidic, alkaline, oxidative, photolytic, and thermal conditions were performed to investigate the stability profile of Adagrasib. Degradation products were characterized using liquid chromatography‐tandem mass spectrometry (LC‐MS/MS), and their possible structures were predicted based on mass fragmentation patterns. The validated method demonstrated its capability to reliably quantify Adagrasib and its impurities at trace levels, ensuring rigorous quality control of the drug substance. The integration of degradation product identification and characterization further enhances its utility in pharmaceutical development. This method offers a robust analytical tool for monitoring the quality of Adagrasib drug substance, ensuring compliance with regulatory requirements and supporting patient safety.