Phase II trial of liposomal doxorubicin (Doxil®) in advanced soft tissue sarcomas

Purpose: To assess the objective response rate, toxicity experienced, progression-free survival, and overall survival of patients with previously untreated advanced soft tissue sarcomas treated with a liposomal doxorubicin formulation (Doxil). Methods: Patients with metastatic or recurrent soft tissue sarcoma who had received no prior chemotherapy for advanced disease were treated with liposomal doxorubicin (Doxil) according to a two stage accrual design. Doxil was administered at 50 mg/m² every 4 weeks. A total of 15 patients were treated and are evaluable for response and toxicity. Results: The male/female ratio was 7/8, the median age was 60 years (34-75) and the ECOG performance status was 0-1 in > 90% of patients. Leiomyosarcoma (7/15) and malignant fibrous histiocytoma (2/15) were the most common histologic diagnoses. No objective responses were observed in the 15 evaluable patients. No lethal toxicity occurred. Grade 3-4 leukopenia or neutropenia were reported in 3/15 (20%) patients. Grade 3 mucositis or hand-foot syndrome occurred in 2/15 (13%) and 1/15 (7%) patients respectively and seemed more severe in older patients. The median time to progression was 1.9 months (range 0.9-6.2). Twelve patients have now died. The Kaplan-Meier estimate of median overall survival is 12.3 months. As called for in the study design, accrual was terminated because no responses were obtained in the first 15 patients. Conclusion: Though well-tolerated, Doxil given according to this dose and schedule to patients with advanced soft tissue sarcoma had no significant therapeutic activity. A correlation between older age and slcin/mucosal toxicity of Doxil is suggested in this study but needs confirmation. Future investigations of Doxil in soft tissue sarcomas should use a different schedule and dose.