Small-molecule FGFR-targeted medicinal chemistry: Advances since 2020 and future perspectives.

FGFR alterations, including fusions, amplifications, rearrangements, and mutations, exist as pathogenic drivers or bypass mechanisms in numerous diseases and cancers. Thus, FGFRs represent crucial therapeutic targets, particularly in oncology. Various agents, especially selective FGFR inhibitors, have shown promising therapeutic potential in oncological diseases. However, off-target toxicities (e.g., hyperphosphatemia) and acquired drug resistance associated with FGFR inhibitors often result in disease progression and unfavorable outcomes for patients, constraining clinical utility. This drives next-generation FGFR therapeutics development, particularly enhancing isoform selectivity and overcoming resistance mutations. This review summarizes FGFR protein architecture, biological functions, and disease associations, while highlighting advances (2020-present) in FGFR inhibitors and degraders, including design strategies, SARs, binding modes, and biological evaluation. Additionally, the unique mechanisms underlying subtype selectivity and resistance to drug-resistant mutations are discussed, providing strategic insights for developing improved FGFR-targeted agents.