Phase II trial of idarubicin (4-demethoxydaunorubicin) in advanced breast cancer. The Clinical Screening Group of the European Organization for Research and Treatment of Cancer.

A phase II trial of idarubicin (IDR-4 demethoxydaunorubicin) was carried out in patients with advanced breast cancer. A dose of 45 mg/m2 was given orally once every 3 weeks. A total of 66 eligible patients were entered into the trial, 56 of whom were evaluable for response (65 were evaluable for toxicity at least). Therapeutic activity was demonstrated with an overall objective response rate of 21% (95% CI: 11-32%). When used as a first-line treatment, the response rate was 33% (95% CI: 9-57%) but this dropped to 17% when the treatment was administered after chemotherapy. Nausea-vomiting was the most frequent and severe non-hematological toxicity observed (WHO grade 3-4: 29%). Loss of hair was noticed in 48% of the patients but only 4% suffered from complete alopecia. Moderate myelotoxicity was reported but no cardiac dysfunction was noticed. IDR could be very advantageous as compared to other anthracyclines, due to its simplicity of administration associated with the lack of risk of extravasation or chemical phlebitis and also the possibility of it being able to reduce cardiotoxicity. Even if the equiefficacy of IDR and DXR has not, as yet, been clearly demonstrated, IDR should be chosen with preference to DXR when administration is not suitable.