Biweekly Pegylated Liposomal Doxorubicin (Caelyx) in Heavily Pretreated Metastatic Breast Cancer: A Phase 2 Study

Abstract

BackgroundPegylated liposomal doxorubicin (PLD) has shown to be as effective as conventional doxorubicin in the treatment of metastatic breast cancer but provides a lower risk of cardiotoxicity. This phase 2 study in heavily pretreated patients with metastatic breast cancer was initiated to evaluate a biweekly instead of a 4-week schedule of PLD in order to obtain a more flexible and tolerable regimen. Patients and MethodsA total of 25 patients with 2 or more prior lines of chemotherapy for metastatic disease were treated with PLD (25 mg/m2) at 2-week intervals for a maximum of 12 courses. Pretreatment with anthracyclines was allowed as long as the cumulative doxorubicin dose at study entry was below 400 mg/m2. Most patients were pretreated with anthracyclines, taxanes, vinorelbine, alkylating agents, and capecitabine. ResultsThe clinical benefit rate, ie, objective response or stable disease, for at least 6 months was 22.7% for all patients and 22.2% in anthracycline- and taxane-pretreated patients, respectively. Median duration of clinical benefit and median time to progression were 12.5 months (95% confidence interval [CI], 10.1-32.3) and 7 weeks (95% CI, 5.4-8.6), respectively. Median overall survival was 9.6 months (95% CI, 5.4-13.9). One- and 2-year survival rates were 38% and 4%, respectively. Myelosuppression was low, with no grade 3 or 4 neutropenia or thrombocytopenia. Most common nonhematologic toxicities were nausea, alopecia, asthenia, and hand–foot syndrome. The low rate of hematologic toxicity and hand–foot syndrome is clinically noteworthy. ConclusionBiweekly PLD is an easily manageable schedule with a favorable toxicity profile. Efficacy was moderate in heavily pretreated patients.