Design, synthesis and biological evaluation of 5-amino-1H-pyrazole-4-carboxamide derivatives as pan-FGFR covalent inhibitors

The aberrant activation of FGFRs plays a critical role in various cancers, leading to the development of several FGFR inhibitors in clinic. However, the emergence of drug resistance, primarily due to gatekeeper mutations in FGFRs, has limited their clinical efficacy. To address the unmet medical need, a series of 5-amino-1H-pyrazole-4-carboxamide derivatives were designed and synthesized as novel pan-FGFR covalent inhibitors targeting both wild-type and the gatekeeper mutants. The representative compound 10h demonstrated nanomolar activities against FGFR1, FGFR2, FGFR3 and FGFR2 V564F gatekeeper mutant in biochemical assays (IC50 = 46, 41, 99, and 62 nM). Moreover, 10h also strongly suppressed the proliferation of NCI–H520 lung cancer cells, SNU-16 and KATO III gastric cancer cells with IC50 values of 19, 59, and 73 nM, respectively. Further X-ray co-crystal structure revealed that 10h irreversibly binds to FGFR1. The study provides a new promising point for anticancer drug development medicated by FGFRs. The emergence of drug resistance caused by gatekeeper mutations in FGFRs has limited the current drug clinical efficacy, representing a significant unmet medical need. In this study, a series of 5-amino-1H-pyrazole-4-carboxamide derivatives were designed and synthesized as novel irreversible pan-FGFR inhibitors. The representative compound 10h exhibited high potency against FGFR1, FGFR2, FGFR3, and FGFR2 V564F with IC50 values of 46, 41, 99, and 62 nM, respectively. Moreover, 10h also strongly suppressed the proliferation of FGFR1-amplified NCI–H520 lung cancer cells, FGFR2-amplified SNU-16 and KATO III gastric cancer cells with IC50 values of 19, 59, and 73 nM, respectively. Further X-ray crystal structures revealed that 10h irreversibly binds to FGFR1. [Display omitted] •A series of 5-amino-1H-pyrazole-4-carboxamide derivatives were designed as FGFR covalent inhibitors.•10h can overcome drug resistant FGFR gatekeeper mutants.•X-ray co-crystal structure revealed 10h irreversibly binds to FGFR1.