Arsenic derivatives in hematologic malignancies: A role beyond acute promyelocytic leukemia?

The importance of arsenic trioxide (As₂O₃) has been underscored over the last decade due to its efficacy against acute promyelocytic leukemia (APL), a disease in which this agent has been associated with complete hematologic and molecular remission rates of 87% and 83%, respectively. The different molecular mechanisms of action of Asi₂O₃ suggest its applicability in hematologic malignancies other than APL. However, responses obtained thus far have consisted of improvements in signs and symptoms without the elimination of a given disease. Toxicities derived from As ₂O₃ are significant but manageable and reversible. However, the risk/benefit ratio of As₂O₃ in hematologic malignancies other than APL is still unclear. The development of new generations of orally bioavailable inorganic, as well as new organic, arsenic compounds with improved toxicity profiles may bolster the therapeutic application of arsenic derivatives in hematologic malignancies such as leukemia, multiple myeloma and myelodysplastic syndromes.