A phase II study of idarubicin (4-demethoxydaunorubicin) in advanced myeloma.

Idarubicin (IDA) is an anthracycline analog which differs from the parent compound by the substitution of a C4 methoxyl group with an hydrogen atom in the aglycone moiety. This drug has shown greater potency and activity in experimental and human leukemias and lymphomas by intravenous and oral routes of administration together with less cardiotoxicity than doxorubicin (DX) and daunorubicin (DNR). We have treated 15 patients with advanced multiple myeloma (MM) refractory or relapsed to standard chemotherapy regimens. The treatment schedule consisted of idarubicin 40 mg/m2 orally on day 1 every 3 weeks for 6-8 months. We obtained 8/14 partial response, 4/14 minor response and 2 progressions. One patient was not evaluable for the response because of liver toxicity not related to IDA administration. The median duration of response was 8 months with a minimum of 2 and a maximum of 12 months. Hematologic toxicity occurred in about 20% of patients and no treatment was delayed. Cardiotoxicity, defined as impairement of left ventricular ejection fraction (LVEF), was observed in one case. The major systemic toxicity observed was nausea in 80% of patients and vomiting in 40%. Hair loss resulting was socially acceptable. These results indicate that IDA is useful as a single agent, easy to administer, not cross resistant with DX and recommended for a combination regimen.