Eighty patients with measurable metastatic colon or renal cancer, melanoma, or sarcoma entered these Phase II studies. A dose of 25 mg/m2/day of Pirarubicin (THP) for 3 consecutive days every 4 weeks for the first patients, and then 20 mg/m2/day for 3 days every 3 weeks was given by i.v. push. These patients received 225 cycles for a median cumulative dose of 165 mg/m2 (range: 55-630). The mean number of cycles given was 2.8 (range: 1-8). Only 3 partial responses and 18 stable disease (22%) were observed. Hematologic toxicity was the main problem; it was responsible for one death and a 19% and 44% incidence of grade 3 and 4 WHO neutropenia, respectively. Alopecia was rare (4%). Chemotherapy was discontinued in three cases because of suspicion of cardiac toxicity, but only one patient had a significant drop in left ventricular ejection fraction at a cumulative THP dosage of 120 mg/m2. A lack of efficacy in renal and colon cancer and melanoma was presupposed and confirmed by these trials. Due to pretreatment with anthracycline in most patients, definite evaluation of THP in soft tissue sarcoma could not be given.