pan-RAS

Class

pan-RAS inhibitor (oral small molecule)

Pathway

RAS-MAPK signaling blockade across wild-type and mutant RAS isoforms

Notes

original target text: pan-RAS (KRAS, NRAS, HRAS -- active/GTP-bound 'ON' state; mutations at codons 12, 13, 61, 117, 146)

RAS proteins (KRAS, NRAS, HRAS) are small GTPase switches that cycle between an inactive, GDP-bound state and an active, GTP-bound ('ON') state. In the active state, RAS proteins recruit and activate downstream kinases in the RAS-MAPK pathway, which drives cell growth and division. Mutations at specific positions (codons 12, 13, 61, 117, 146) impair the protein's ability to turn itself off, locking RAS in the active conformation and producing continuous, growth-factor-independent proliferative signaling. Such mutations are among the most common oncogenic drivers across solid tumors. A pan-RAS inhibitor is designed to bind the active, GTP-bound conformation shared by all three RAS isoforms and by many different mutant variants, rather than targeting one specific mutation. This broader approach addresses the reality that tumors are genetically heterogeneous and can shift between mutant forms or rely on more than one isoform, and it may also limit certain resistance mechanisms that arise when only a single mutant is blocked. Because normal, non-mutated RAS also participates in ordinary cell signaling, the same broad coverage that gives pan-RAS inhibitors flexibility across tumor types also raises the possibility of effects on healthy tissues that depend on regulated RAS-MAPK activity, a consideration relevant to how this class of oral small molecules is developed.