A phase II trial of oral 4'demethoxydaunorubicin (DMDR) in inoperable non small cell lung cancer

Oral idarubicin--an anthracycline derivative with unique properties

Idarubicin belongs to a group of anthracyclines in which the methoxyl group in position 4 of the D ring in the aglycone moiety is replaced by a hydrogen atom. Lipophilicity is increased compared with other anthracyclines; as a result, idarubicin is the first anthracycline that can be administered orally while at the same time retaining its antitumor activity. In addition, the lipophilicity enables the transition of the substance, especially of the metabolite, to the cerebrospinal fluid. The metabolite idarubicinol is formed in high concentrations; this is particularly true with oral administration. Compared with all other anthracyclines, it has a very long half-life. It is the first anthracycline metabolite to have the same cytotoxic activity as the parent compound. The cardiotoxicity of idarubicin, being lower than that of other anthracyclines at equally effective doses, is even more reduced with oral administration. Preclinical and clinical experiences with oral idarubicin are reviewed.

Idarubicin: a second-generation anthracycline

Because of its in vitro activity in leukemic cell lines and Phase I studies of acute leukemia, Phase II and III clinical trials with idarubicin hydrochloride were conducted in patients with acute lymphocytic leukemia or acute nonlymphocytic leukemia. In the Phase III comparative trials between the combinations of idarubicin and cytarabine and daunorubicin hydrochloride and cytarabine, the idarubicin/cytarabine combination resulted in significantly greater complete remission rates and longer overall survival in two of three studies conducted in the US. As a result, the Food and Drug Administration approved intravenous idarubicin with a Class 1A rating in September 1990 for use in combination with other antileukemic drugs (e.g., cytarabine) for the treatment of acute myelogenous leukemia in adults. The recommended dose of idarubicin is 12 mg/m2 daily for three days by slow intravenous injection in combination with cytarabine. Although idarubicin causes myelosuppression similar to that described with daunorubicin, the incidence of cardiotoxicity in animal models is lower. Idarubicin also has the advantage of oral administration, but the oral formulation of the drug remains investigational. The use of idarubicin in pediatric patients also remains to be established.