Myotax: a phase II trial of docetaxel plus non-pegylated liposomal doxorubicin as first-line therapy of metastatic breast cancer previously treated with adjuvant anthracyclines

Aim

Non-pegylated liposomal doxorubicin (NPLD) has demonstrated equivalent antitumour activity to conventional doxorubicin and a significantly lower risk of cardiotoxicity when given as a single agent or in combination with cyclophosphamide. This phase II trial was performed to evaluate the efficacy and the safety of NPLD and docetaxel combination in patients with metastatic breast cancer previously exposed to adjuvant anthracyclines.

Patients and methods

Thirty-four patients received NPLD 60 mg/m² and docetaxel 75 mg/m² in a 21-day cycle as first-line therapy of metastatic breast cancer. Treatment was planned for six cycles and was continued until progression or toxicity.

Results

Objective response rate among response-assessable patients was 79% (95% CI (confidence interval), 64–94%) and 27% (95% CI, 11–43%) presented a complete response. Median progression free survival was 11.3 months (95% CI, 6.2–13.3 months) and median overall survival was 28.2 months (95% CI, 16–36.4 months). Symptomatic grade 3 cardiotoxicity occurred in 15% of cases and febrile neutropenia in 47% of the patients.

Conclusions

The combination of NPLD and docetaxel demonstrated high antitumour activity in a population of metastatic breast cancer patients exposed to adjuvant anthracyclines and showed an unexpected and unexplained 15% symptomatic left ventricular systolic dysfunction rate.