Phase II studies of p.o. Idarubicin administration, a new daunorubicin analogue (4-demethoxy-daunorubicin), have shown antitumor activity in 23%-31% of previously treated metastatic breast cancer patients, while in untreated patients a response rate of 41% was observed. Our Phase II study has shown an overall response of 23% [1 complete response (CR), 9 partial response (PR), 10/43] with a daily dose of 15 mg/m2 p.o. on days 1,2,3. On the basis of these results we have recently included Idarubicin in combination chemotherapy of breast cancer, substituting Adriamycin by Idarubicin in an FAC schedule. Of 50 consecutive metastatic breast cancer patients who entered the study, 42 patients who received greater than 2 cycles were evaluable. There were 22 premenopausal and 20 postmenopausal patients (mean = 51 years). In 25 patients a performance status of 0-2 (ECOG) was registered and in 17 patients it was 3. Previous radiation had been administered in 34, hormonal therapy in 18, and adjuvant chemotherapy (CMF 5, CMFVP 3) in 8 patients; 22 patients had predominant metastatic sites in soft tissues, 18 in visceral organs, and 2 in the bones. The FIC schedule was administered as follows: 5-fluorouracil 500 mg/m2 i.v. days 1 and 8, Idarubicin 15 mg/m2 p.o. days 1, 2 and 3, and cyclophosphamide 500 mg/m2 i.v. day 1. An objective response was observed in 23 (5 CR, 18 PR) out of 42 patients (53%, CR 12%). Soft tissue metastases responded in 55% (12/22), visceral organs in 61% (11/18), and no response was observed in bone lesions (0/2). The median remission duration was 8 months (3-16+). Toxicity was mild, expressed mainly in the form of nausea/vomiting, grade I and II in 64% of the patients. Alopecia was very mild (grade I and II in 23% of the patients). Leukopenia grade I-II was observed in 21% of the patients. In 4 patients reversible ECG changes occurred. Left ventricular ejection fraction did not show any pathological changes. The Idarubicin-containing combination chemotherapy we have used has the following characteristics: easier administration (p.o. anthracycline, no risk of tissue extravasation), lower toxicity (cardiotoxicity, alopecia, and myelosuppression in particular), and a notable antitumor activity.
