A phase II study of Doxil (liposomal doxorubicin): Lack of activity in poor prognosis soft tissue sarcomas

Background. Liposomal doxorubicin (Caelyx, Doxil) delivers doxorubicin to a tumor, but has a vastly altered pharmacology and attenuated acute and chronic toxicities. Therefore, its efficacy in soft tissue sarcomas is worth exploring. Patients and methods. Sixteen patients with recurrent or metastatic soft tissue sarcomas who had not failed prior doxorubicin were accrued into this phase II study. Patients were treated with Doxil at a dose of 50 mg/m(2) every four weeks. Results. No responses were seen but three patients were removed from study after only one cycle of treatment. Moreover, leiomyosarcoma was the most common histology and most patients had low grade, and bulky, disseminated tumors. Treatment was well tolerated with no episodes of grade 4 toxicity and only five episodes of grade 3 toxicities: two episodes of neutropenia and one each of stomatitis, dermatologic toxicity and nausea and vomiting. Conclusions. Doxil's lack of activity in this study of patients with adult soft tissue sarcoma may be related to the poor prognostic features of our population. We confirm its favorable toxicity profile and suggest that additional studies be done in patients with other characteristics.