Tamibarotene.

Tamibarotene is a new synthetic retinoid drug recently approved for relapsed or refractory acute promyelocytic leukemia (APL) in Japan. It is a specific agonist for retinoic acid receptor alpha/beta. Compared to all-trans retinoic acid (ATRA), a natural retinoid indicated for a first-line treatment of APL, tamibarotene is chemically more stable and several times more potent as an inducer of differentiation in promyelocytic leukemia cells. In contrast to ATRA, whose plasma concentration declines considerably during daily administration, tamibarotene sustains plasma level probably due to a lower affinity for cellular retinoic acid binding protein. Furthermore, adverse side effects were milder than those of ATRA in clinical trials. Clinical trials held in Japan showed that tamibarotene had efficacy in APL patients who had relapsed from ATRA-induced complete remission. Recently, better understanding of the various mechanisms of action of retinoids has stimulated great interest in its potential use for treatment of various diseases. Tamibarotene is being investigated for treatment of multiple myeloma and Crohn's disease in clinical trials. This review focuses on tamibarotene's mechanisms of action, chemical properties, pharmacokinetics and its use in APL as well as its potential use in various disorders. (c) 2007 Prous Science.