A combination of artemisinin, moxidectin, and doxorubicin drugs can selectively and efficiently induce apoptosis in acute lymphoblastic and chronic myeloid leukemia cells in vitro and ex vivo

<title>Abstract</title> Acute lymphoblastic leukemia (ALL) and chronic myeloid leukemia (CML) are blood cancers that often resist traditional chemotherapy and other treatments, likely due to their ability to evade apoptosis. Therefore, inducing apoptosis in leukemia cells using innovative drug combinations may be the most effective therapeutic approach. Drug repurposing and combination therapy offer excellent opportunities for treating leukemia. Methods for two-drug combinations are available, but methods for multidrug combinations (three or more drugs) are scarce and much more complex to analyze. We calculated the EC50 for each of the eight repurposed drug candidates: artemisinin (AM), chloroquine (CQ), primaquine (PQ), mefloquine (MQ), ivermectin (IM), moxidectin (MD), doxorubicin (DR), and minocycline (MC). We found that a combination of AM, MD, and DR at ½ of EC50 concentration, such as 1 µM, 10 µM, and 1.5 µM, respectively, induced more than 80% apoptosis (i.e., strong quantal effect) in leukemia cell lines K562 and Jurkat, as well as in ex vivo ALL and CML cells, except in peripheral blood lymphocytes (PBLs). This occurred as a result of cell cycle arrest in the S and G2/M phases, a drastic loss of mitochondrial membrane potential (ΔΨm), high lysosome accumulation, and caspase 3 activation as evidence of apoptosis cell death. To our knowledge, this is the first study combining a concentration-response analysis of eight drugs from three groups of compounds (antimalarial, anthelmintic, and antibiotic) across three dose ranges. Our method of combining drugs, together with knowledge of drug mechanisms, increases the therapeutic response of leukemia cells toward apoptosis when conventional, repurposed, cytotoxic agents are used. Therefore, these data establish the combination of AM, MD, and DR as a potential drug target for treating ALL and CML leukemias.