Forty-one evaluable patients with malignant melanoma resistant to other chemotherapeutic agents received 9 mg/m2 of piperazinedione every 3 weeks. Two patients had partial responses and one additional patient had stable disease. One of the partial responses occurred in a patient with subcutaneous metastases and the other occurred in a patient with pulmonary and osseous metastases. Both antitumor responses occurred in the 17 patients with a performance status of ≥80%. The dose-limiting toxicity was myelosuppression; thrombocytopenia was more frequently observed than granulocytopenia.
