Mechanisms of action of arsenic trioxide.

Arsenic trioxide has shown substantial efficacy in treating both newly diagnosed and relapsed patients with acute promyelocytic leukemia (APL). As a single agent, it induces complete remissions, causing few adverse effects and only minimal myelosuppression. These successes have prompted investigations to elucidate the mechanisms of action underlying these clinical responses. Substantial data show that arsenic trioxide produces remissions in patients with APL at least in part through a mechanism that results in the degradation of the aberrant PML-retinoic acid receptor alpha fusion protein. Studies have also investigated concerns about the toxicity and potential carcinogenicity of long-term exposure to…