A Phase II randomized trial of lapatinib with either vinorelbine or capecitabine as first- and second-line therapy for ErbB2-overexpressing metastatic breast cancer (MBC).

Background: Lapatinib (L), a dual kinase inhibitor of epidermal growth factor receptor and ErbB2, is effective in the treatment of ErbB2+ MBC in combination with capecitabine (C) following progression after trastuzumab, anthracyclines, and taxanes. Vinorelbine (V) is an important chemotherapy option in MBC, and multiple Phase II trials have been conducted in combination with trastuzumab. This randomized, open-label, multicenter, Phase II study (LAP112620, VITAL) evaluated the efficacy and safety of L with either V or C in women with ErbB2+ MBC. Methods: Patients with MBC who had received 1 chemotherapy regimen in the metastatic setting were randomized 2:1 to either L 1250 mg orally once daily (QD) continuously plus V 20 mg/m2 intravenously on Days 1 and 8, every third week, or L 1250 mg orally QD continuously plus C 2000 mg/m2/day orally in 2 doses 12 hours apart on Days 1-14 every third week. Patients were stratified by prior receipt of therapy for MBC (Y/N) and site of metastatic disease (visceral/soft tissue or bone-only). The primary endpoint of progression-free survival (PFS) was assessed once all subjects had been followed for a minimum of 6 months or had otherwise progressed, died or withdrawn, if sooner. The primary focus was to evaluate PFS in the L plus V arm with a descriptive intent only. Other endpoints included overall response rate, overall survival, and safety. Patients progressing on one treatment arm were given the option of crossing over to the other arm. Results: 112 patients were randomized. The results and conclusions sections will be updated once the primary analysis has been completed in September 2012. [ABSTRACT FROM AUTHOR]