KMT2A and acute myeloid leukemia: Phase I trial completed in adult and pediatric patients with relapsed or refractory acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) harboring MLL gene rearrangements (ClinicalTrials.gov identifiers: NCT01684150, NCT02141828); Clinical trials currently ongoing to examine the combination of Pinometostat and standard DNA damage-inducing cancer treatment modalities (ClinicalTrials.gov identifiers: NCT03701295, NCT03724084)