Pyrimidine-Based Third-Generation Tyrosine Kinase Inhibitors: A Medicinal Chemistry Perspective

Introduction: The emergence of resistance to conventional treatments signifies a critical challenge in oncology. 3rd-Gen Tyrosine Kinase Inhibitors (TGTKIs) were driven by the need to overcome this resistance. The objective of this study is to explore the medicinal chemistry advancements underpinning TGTKIs, with a focus on key pyrimidine-derived inhibitors, including osimertinib, lazertinib, almonertinib, furmonertinib, rezivertinib, and rociletinib. Additionally, it discusses their structural optimizations, selectivity profiles, and clinical performance, and addresses emerging resistance mechanisms and future directions in EGFR-targeted therapy. Methods: A comprehensive search of major medical databases was conducted to recognize and integrate related literature. Result: Pyrimidine-based EGFR TKIs, which have emerged as an efficient structural class, possess potent inhibition with improved pharmacokinetic and pharmacodynamic characteristics. Discussion: TGTKIs selectively target mutant EGFR to overcome the resistant mutation T790M, a major clinical challenge against first- and second-generation TKIs. They have specific molecular designs and pharmacokinetic properties supporting their action. Conclusion: TGTKIs have transformed the therapeutic concept for mutant NSCLC patients and have offered unprecedented efficacy and durability compared to earlier-generation inhibitors.