A phase II clinical trial of echinomycin in metastatic soft tissue sarcoma

Echinomycin, a cyclic peptide in the family of quinoxaline antibiotics, was evaluated in patients with metastatic, soft tissue sarcoma not previously treated for metastatic disease. The starting dose of echinomycin was 1,200 mcg/m2 administered intravenously, once weekly × 4, followed by a two-week break. The protocol design called for dose escalation on subsequent cycles of therapy, but because of significant toxicity, dose escalation occurred in only 5 of 25 treatment cycles. Severe nausea and vomiting was the most common toxicity. No clinical responses were observed in the 12 evaluable patients. Echinomycin at this dose and schedule is inactive in metastatic soft tissue sarcoma.