Sapacitabine (also known as CYC-682) is an orally bioavailable 2′-deoxycytidine analog that is in clinical trials for hematologic malignancies and solid tumors. Sapacitabine is primarily metabolized by plasma, gut and liver amidases into the active metabolite CNDAC. This metabolite is subsequently transported inside cells and then phosphorylated by deoxycytidine kinase (dCK) into CNDAC triphosphate before being incorporated into cellular DNA. Sapacitabine participated in phase III clinical in older patients with acute myeloid leukemia (AML); however, it failed to meet its primary endpoint of the statistically significant improvement in overall survival (OS). The drug has been also involved in phase II clinical trials for the treatment of patients with myelodysplastic syndromes, cutaneous T-cell lymphoma, and non-small cell lung cancer. In addition, in combination with olaparib the drug was studied in phase I/II trial as a possible treatment for breast cancer with a BRCA mutation. On July 1, 2010, Cyclacel Pharmaceuticals announced that the U.S. Food and Drug Administration (FDA) has granted orphan drug designation to the company’s sapacitabine for the treatment of both acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS).