Pyrimidine-Based Hybrids for Epidermal Growth Factor Receptor Targeting: Structure-Activity Relationships and...

Pyrimidine has become an important scaffold for designing anticancer drugs because of its planar aromatic structure, synthetic versatility, and ability to establish key interactions with its target. This heterocyclic scaffold is an essential component of nucleic acids and many biologically active molecules, which makes it highly relevant for therapeutic application. In recent years, significant attention has been directed toward pyrimidine-based hybrid molecules, in which the pyrimidine core is integrated with other bioactive scaffolds to enhance the anticancer activity. The present review encompasses a wide range of such hybrids, including pyrimidine-quinoline, pyrimidine-indole, pyrimidine-triazole, pyrimidine-chalcone, pyrimidine-pyrazole, pyrimidine-imidazole, pyrimidine-thiazole, and pyrimidine-oxadiazole derivatives. This hybridization strategy facilitates the development of multitargeted agents capable of modulating key signaling pathways in cancer. Among these, epidermal growth factor receptor (EGFR) has gained particular importance due to its central role in tumor growth, survival, and metastasis. This review focuses on the last 2 years' advancements (from Jan 2025 to early 2026) in the development of pyrimidine-containing hybrid molecules as EGFR inhibitors. Different hybridization techniques involving pyrimidine linked or fused with another moiety are comprehensively discussed. Furthermore, the present review summarizes the structure-activity relationship (SAR), mechanistic pathway, and molecular interactions responsible for their anticancer potential, with a specific emphasis on their EGFR inhibitory activity, including effects on mutant EGFR. Notably, compounds 16a and 16b (pyrazolo[3,4-d]pyrimidine-sulfonamide hybrids) were identified as the most active EGFR inhibitors with IC₅₀ of 0.069 and 0.064 µM, respectively. Additionally, pyrimidine-based anticancer agents under clinical investigation as EGFR inhibitors are briefly highlighted. Overall, pyrimidine-based hybrids represent a promising direction as next-generation anticancer therapeutics.