Treatment of advanced breast cancer with sterically stabilized liposomal doxorubicin: Results of a multicenter phase II trial

Purpose: A multicenter phase II study to determine the activity and toxicity of Caelyx (Doxil; Sequus Pharmaceuticals Inc, Menlo Park, CA) in patients with metastatic breast cancer, Patients and Methods: Seventy-one patients with stage IV breast cancer were treated with Caelyx at doses of 45 to 60 mg/m(2) every 3 to 4 weeks for a maximum of six cycles, Twenty eight patients had received prior chemotherapy with a nonanthracycline regimen, Fifty-two patients had disease at multiple sites, Hepatic and pulmonary disease were the predominant metastatic site in 50 patients, Response was assessable in 64 cases, Results: Sixteen patients achieved a partial response and four a complete response (overall response rate, 31%; (95% confidence interval, 20% to 43%). Twenty patients (31%) had stable disease on treatment, Neutropenia greater than or equal to grade 3 occurred in 10% of cycles (27% of patients) and mucositis greater than or equal to grade 3 in 10% of cycles (32% of patients), Significant alopecia was rare and routine prophylactic antiemetics were not required, At doses of 60 mg/m(2) every 3 weeks, seven of 13 patients had greater than or equal to grade 3 skin toxicity; overall, this toxicity complicated 25% of treatment cycles, The incidence of greater than or equal to grade 3 skin toxicity was greatly reduced at doses of 45 mg/m(2) every 4 weeks, occurring in five of 32 patients and affecting only 5% of 126 treatment cycles. Conclusion: Caelyx is an active agent in advanced breast cancer with ct safety profile that differs markedly from nonliposomal doxorubicin, A regimen of 45 mg/m(2) every 4 weeks was well tolerated in this cohort of women with advanced poor-prognosis breast cancer, The mild myelosuppression seen with this regimen would favor its use in combination chemotherapy. (C) 1997 by American Society of Clinical Oncology.