MRTX-1133 (MRTX1133; MRTX 1133) is a novel, potent, noncovalent, and selective KRAS G12D inhibitor with antitumor activity. It is efficacious in a KRASG12D mutant xenograft mouse tumor model. KRASG12D, the most common oncogenic KRAS mutation, is a promising target for the treatment of solid tumors. However, when compared to KRASG12C, selective inhibition of KRASG12D presents a significant challenge due to the requirement of inhibitors to bind KRASG12D with high enough affinity to obviate the need for covalent interactions with the mutant KRAS protein.