Cell Therapeutics, Inc. announced that it has received notification from the U.S. Food and Drug Administration (FDA) that the partial clinical hold on tosedostat (IND 075503) has been removed and all studies underway may continue. Tosedostat is a first-in-class selective inhibitor of aminopeptidases, which are required by tumor cells to provide amino acids necessary for growth and tumor cell survival, and is under development for the treatment of blood-related cancers. Tosedostat is currently being studied in the United States and European Union in investigator-sponsored and cooperative group-sponsored Phase 2 trials in elderly patients with newly diagnosed and relapsed acute myeloid leukemia (AML) and high-risk myelodysplastic syndromes (MDS).