HTS-derived covalent inhibitors hit active, GTP-bound KRAS G12C
- Approved KRAS G12C drugs mostly trap the inactive GDP state and face resistance; this series targets the active GTP-bound state instead.
- A keto-indolizine HTS hit with an aniline-derived acrylamide binds Cys12 in the switch-II pocket; crystallography shows the warhead engaging the γ-phosphate of a GTP analogue.
- Optimization gave compound 17, orally bioavailable in preclinical species, which prolongs disruption of KRAS–cRAF binding and ERK signalling and produced complete regression in a pancreatic cancer xenograft.
💡 Points
Using the γ-phosphate to position the warhead is neat: GTP-state selectivity comes from the nucleotide itself, not only the pocket. The comparison I'd want is against RAS(ON) tri-complex inhibitors, which need cyclophilin A while this doesn't. Acrylamide reactivity and proteome-wide cysteine selectivity also matter more here than for GDP-state binders.