A patent review of small molecular inhibitors targeting EGFR exon 20 insertion (Ex20ins) (2019-present)

Introduction: Mutations in epidermal growth factor receptor (EGFR) kinase domain consistently activate downstream signaling pathways, such as the PI3K/AKT/mTOR and RAS/RAF/MEK, thereby promoting tumor growth. Although the majority of non-small cell lung cancer (NSCLC) patients harboring EGFR mutations are sensitive to existing EGFR tyrosine kinase inhibitors (EGFR-TKIs), there remains an unmet clinical need for effective therapies targeting EGFR Ex20ins mutations, making direct targeting EGFR Ex20ins mutations a promising therapeutic strategy.

Areas covered: This review covers the progress of clinical studies targeting EGFR Ex20ins inhibitors and summarizes recent (1 January 2019 - 30 April 2024) patents disclosing EGFR Ex20ins inhibitors available in the Espacenet and CAS SciFinder databases.

Expert opinion: An increasing number of EGFR Ex20ins inhibitors are being developed and reported. Existing inhibitors are focused on enhancing the efficacy of EGFR Ex20ins inhibitors and addressing the challenge of targeted resistance by optimizing the second - or third-generation EGFR inhibitors and developing innovative skeleton molecules. Moreover, the development of targeted protein degraders, allosteric inhibitors, and combination therapies provide additional approaches to address EGFR Ex20ins mutations. However, bypass resistance, selectivity, and drug sensitivity still pose challenges in this field.