A Study Evaluating the Efficacy and Safety of Lapatinib + Vinorelbine in ErbB2 Positive Metastatic Breast Cancer Patients

The objective of this phase II study is to gain first information on the efficacy (PFS, ORR and OS) and safety of lapatinib plus vinorelbine in patients with HER2 positive breast cancer pretreated with a combination therapy (chemotherapy, hormonal therapy) including lapatinib for metastatic disease. The sample size is not based on statistical consideration. Thirty 30 patients are considered appropriate for a phase II study to gain first information on the efficacy and safety of the study treatment in the study indication. Only descriptive statistical methods will be used to summarize the study results. Kaplan-Meier estimates will be calculated for PFS and OS. Median PFS and OS time and corresponding two sided 95% confidence intervals will be provided. Categorical endpoints will be summarized in frequency tables and 95% confidence intervals will be calculated for the objective response rate (ORR) using RECIST. All safety variables will be summarized descriptively The incidence of adverse events will be summarized by MedDRA terms in a descriptive manner. The progression free survival time (PFS) is the primary efficacy endpoint of the study. Secondary outcomes are overall survival (OS) and objective response rates (ORR) using RECIST. Safety outcomes are adverse events, safety laboratory data, physical examinations, vital signs, LVEF, ECG data and ECOG performance status Definitions: The objective response rate is the rate of subjects with complete response (CR) or partial response (PR). Progression-free survival: The time to progression or death is defined as the time from study entry until the first observation of disease progression or death due to any cause (whichever occurred earlier). Only those death will be considered, which occurs within 84 days of the last tumor assessment or study entry (whichever is later). If a patient has no progression before a clinical cut-off or the death date is beyond the above-mentioned time interval after last tumor assessment, time to progression/death is censored on the date of last tumor assessment or study entry (in case of no post-baseline tumor assessment). Overall survival will be calculated from study entry until death. For patients lost to follow-up, data will be censored at the time the patient was last determined to be alive. As efficacy data of vinorelbine plus lapatinib are not available so far and the current protocol is applied as 2nd or 3rd line therapy for metastatic disease an ORR from 30-40% and a median PFS from 4-6 months is expected.