An orally bioavailable inhibitor of the KRAS-mitogen-activated protein kinase (MAPK) signaling pathway, with potential antineoplastic activity. Upon oral administration, JAB-3312 blocks signaling through the KRAS-MAPK pathway. This prevents proliferation of susceptible cancer cells in which the KRAS-MAPK signaling pathway is overactivated. The Ras-MAPK pathway is often hyperactivated in cancer cells due to specific mutations and rearrangements, such as those seen in KRAS-mutant cancer cells, and drives cancer cell proliferation and survival.