OnCo
ideasIdea

Covalent chemistry for the RAS mutations that still have no drug

One RAS mutation can now be drugged because it offers a reactive handle. Most RAS mutations do not, so new chemistry is needed to grab other amino acids.

KRAS G12C inhibitors work by covalently modifying a cysteine. G12D, G12V and G13D, which together account for most RAS-driven cancer, lack that cysteine. Aspartate-targeting and lysine-targeting covalent chemistries, non-covalent tri-complex RAS(ON) inhibitors and pan-RAS agents are all in early clinical development. The proposal is a focused public-private chemistry programme on non-cysteine covalent warheads with tolerable reactivity, plus open sharing of failed warhead chemotypes.

Hypothesis
A non-cysteine covalent warhead class can achieve selective, durable engagement of KRAS G12D in vivo with acceptable off-target proteome reactivity, giving deeper responses than reversible binders.
Rationale
Covalency solves the picomolar-affinity requirement created by RAS's high GTP affinity; the G12C precedent shows that irreversible engagement translates into clinical activity.
What would test it
Chemoproteomic profiling of candidate warheads across the reactive proteome, then in vivo pharmacodynamics in KRAS G12D pancreatic and colorectal models against a benchmark RAS(ON) inhibitor.
Maturity
early clinical
Who has to act
industry
Cost to try
Large (over $50M)
Years to first evidence
5
Bottlenecks it attacks
  • The undruggable drivers · The proteins that drive most cancers, such as MYC, mutant p53 and most RAS variants, still have no good drug.

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