Provided are methods for treating a disease, disorder, or condition associated with an acid ceramidase (AC) biological activity. The methods include administering to a subject in need thereof a composition including an AC inhibitor and at least one additional active agent, such as a C6-ceramide nanoliposome (CNL); an inhibitor of a Bcl-2 family protein; a hypomethylating agent; an intensive chemotherapeutic agent such as cytarabine (AraC) and/or daunorubicin; a Hedgehog pathway inhibitor; a targeted agent, such as a FLT2 inhibitor or a EDH1/2 inhibitor; and/or an antibody drug conjugate that targets, for example, CD-33. The composition can include N-[(2S,3R)-1,3-dihydroxyoctadecan-2-yl]2-chloroacetamide (SACLAC) or a pharmaceutically acceptable salt thereof and at least one additional active agent. The disease, disorder, or condition associated with the AC biological activity can be a cancer, such as acute myeloid leukemia (AML).