Phase II study of lapatinib in combination with vinorelbine in patients with HER2 positive recurrent or metastatic breast cancer: A multicentric Turkish Oncology Group (TOG) trial

BackgroundThe aim of this explorative phase II study was to evaluate the activity and safety of lapatinib in combination with intravenous vinorelbine in women with HER2 positive metastatic or recurrent breast cancer.MethodsTwenty-nine patients were enrolled. The primary objectives were response and clinical benefit (CB) rates, secondary objectives were toxicity, response duration and progression free survival. Patients received 1250 mg oral lapatinib continuously once daily and intravenous vinorelbine 20-25 mg/m2 on days 1 and 8, every 3 weeks.ResultsAlthough 25 patients were evaluable for response, according to intend to treat analysis of 28 patients; 14% had confirmed partial response (PR) and 36% had stable disease more than 24 weeks with a CB rate of 50%. Sixty four percent of the patients suffered from grade 3-4 hematologic and 18% from grade 3 extra-hematologic toxicities.ConclusionThe results of this trial provide evidence to further investigate the potential of this combination for patients unsuitable for trastuzumab or who become refractory to trastuzumab.