Abstract: Acute myeloid leukemia (AML) are heterogeneous malignancies arising from the multistep transformation of bone marrow immature cells. The inventors showed that RAS pathway mutations were detected in 40% of FLT3- and NPM1-unmutated AML cases and correlated with higher white blood cell count, blast cell percentage and reduced survival after intensive therapy. Building on genetic models of RAS activation, they highlighted the leukemogenic potential of RAS pathway alterations, and the efficacy and limitations of MEK inhibitors in this context. From high-content chemical screens, the inventors unraveled pyrvinium pamoate—an anthelminthic drug approved in human patients—as displaying a preferential cytotoxicity against RAS activated cells. This potential clinical candidate demonstrated a robust synergistic activity with the MEK inhibitor trametinib, including in primary samples from AML patients.