Ninety-eight patients with previously-treated advanced soft tissue sarcoma, bone sarcoma, or mesothelioma were randomly assigned to one of two intravenous single-agent treatment regimens, either 6-diazo-5-oxo-l-norleucine (DON; brief infusions of 50 mg/m2/day for 5 consecutive days every 4 weeks) or aclacinomycin-A (ACM-A, as 30-min infusions of 100 mg/m2 or 85 mg/m2, administered every 3 weeks). Of 43 patients who were evaluable for response, survival and toxicity, there were two responses (5%) produced by ACM-A; one in a male with mesothelioma, and one in a female with malignant fibrous histiocytoma. None of the 36 evaluable patients treated with DON developed an objective tumor response. Median survival was 4.8 months in the DON treatment arm, and 6.8 months in the ACM-A treatment arm. No patients on the DON arm experienced lethal or life-threatening toxicities, and severe toxicities resulting from this treatment included nausea and emesis (10%), stomatitis (2%), gastrointestinal toxicity (2%), and anemia (2%). Moderate toxicities included vomiting (24%), hematologic toxicity (24%), neurologic toxicity (7%), diarrhea (7%), mucositis (5%), fever (5%), palpitations (2%), hepatotoxicity (2%), bleeding (2%) and edema (2%). Fifteen percent experienced at least one severe reaction, and 63% experienced at least one moderate or greater toxicity. ACM-A was associated with four cases of life-threatening myelosuppression (7%); severe toxicities included myelosuppression (11%), neurologic toxicity (4%), diarrhea (2%), respiratory toxicity (2%), pain and muscle spasms (2%), edema (2%), and ulceration following extravasation (2%).(ABSTRACT TRUNCATED AT 250 WORDS)