Treatment with ROC-325 triggers all of the hallmark features of autophagy inhibition including the accumulation of autophagosomes with undegraded cargo, an increase in lysosomal membrane permeability, deacidification of lysosomes, and elevated LC3B, p62, and cathepsin D expression. In vitro treatment of a panel of human AML cell lines and normal human bone marrow progenitors demonstrate that ROC-325 diminishes AML cell viability (IC50 range 0.7-2.2 µM), antagonizes clonogenic survival, and induces apoptosis in a manner that is therapeutically selective.
In vivo
ROC-325 is well tolerated and no notable toxicities are observed other than a modest, non-significant reversible reduction in mean body weight. Oral administration of ROC-325 to mice bearing RCC xenografts is well tolerated and yields dose-dependent inhibition of tumor growth that is significantly more efficacious than a higher dose of HCQ.