Clinical Trial: NCT02273102

Acute Myeloid Leukemia (AML) is a diverse disease that is fatal in the majority of patients. Acute promyelocytic leukemia (APL) however, a subtype of AML accounting for 5% of all cases, is very curable. APL cells are highly sensitive to the retinoid all-trans-retinoic acid (ATRA), which effectively differentiates the leukemic clone. Over 80% of APL patients can be cured with ATRA based therapies. For patients with non-APL AML, ATRA has little effect. Consequently, 85% of these patients will succumb to their disease despite conventional approaches. Little is known about mechanisms of resistance to ATRA in non-APL AML. This knowledge gap limits the use of ATRA in a disease that already has few effective therapies. The investigators' preliminary data suggest that non-APL AML cells can be re-sensitized to ATRA when combined with lysine-specific demethylase 1 (LSD 1) inhibitors. The investigators' publication in Nature Medicine showed that LSD1 inhibition with tranylcypromine (TCP), unlocked the ATRA-driven therapeutic response in non-APL AML. Notably, treatment with ATRA and TCP markedly diminished the engraftment of primary human AML cells in murine models, indicating that the combination may target leukemia-initiating cells (LIC). The investigators' data identify LSD1 as a therapeutic target and strongly suggest that it may contribute to ATRA resistance in non-APL AML. The investigators' central hypothesis is that ATRA combined with TCP will be safe and effective in a clinical population, and that this approach will suppress LICs and restore myeloid differentiation programs in patients with non-APL AML. Testing this hypothesis with the phase I clinical trial outlined in this protocol, will establish a new treatment paradigm in AML and extend the important anti-cancer effects of ATRA to all AML subtypes.