molecules of the month

MRTX1133 is a non-covalent, reversible, long-acting inhibitor of KRASG12D entering clinical development for cancer as an oral agent. Mutant KRAS proteins are well-known drivers of cancer, and only in recent years have the first KRAS inhibitors been approved. These inhibitors are covalent and only work on the KRASG12C mutation, as they bind to the cysteine created by the mutation.  Regardless, there is significant excitement about KRASG12C inhibitors both as single agents and as treatments in combination, given the well-established role of KRAS in cancer. Beyond KRASG12C, there are several activating mutations of KRAS that drive cancers. KRASG12D is actually the most prevalent KRAS mutant (33% among KRAS mutant tumors), but much harder to drug given the lack of a traditionally…