Lapatinib plus capecitabine is superior to capecitabine alone in women with HER2-positive advanced breast cancer that has progressed after treatment with regimens that included an anthracycline, a taxane, and trastuzumab. (ClinicalTrials.gov number, NCT00078572 [ClinicalTrials.gov].).

This trial demonstrated that a combined targeted strategy with letrozole and lapatinib significantly enhances PFS and clinical benefit rates in patients with MBC that coexpresses HR and HER2.

The addition of lapatinib to capecitabine provides superior efficacy for women with HER2-positive, advanced breast cancer progressing after treatment with anthracycline-, taxane-, and trastuzumab-based therapy. Biomarker studies could not identify a subgroup of patients who failed to benefit from the addition of lapatinib to capecitabine.

Purpose: Brain metastases develop in one third of patients with advanced HER2+ breast cancer.Effective therapy for patients with central nervous system (CNS) progression after cranial radiation is extremely limited and represents a major clinical challenge. Lapatinib, an epidermal growth factor receptor/HER2 inhibitor, was associated with regressions of CNS lesions in a small phase 2 trial. The current study was done to further evaluate the CNS activity of lapatinib. The study was later amended to allow patients who progressed on lapatinib the option of receiving lapatinib plus capecitabine. Experimental Design: Eligible patients had HER2+ breast cancer, progressive brain metastases, prior trastuzumab, and cranial radiotherapy.The primary end point was CNS objective response, defined as z50% volumetric reduction of CNS lesion(s) in the absence of increasing steroid use, progressive neurologic signs and symptoms, or progressive extra-CNS disease. Results: Two-hundred and forty-two patients entered the study. CNS objective responses to lapatinib were observed in 6 % of patients. In an exploratory analysis, 21% of patients experienced a z20% volumetric reduction in their CNS lesions. An association was observed between volumetric reduction and improvement in progression-free survival and neurologic signs and symptoms. Of the 50 evaluable patients who entered the lapatinib plus capecitabine extension, 20% experienced a CNS objective response and 40% experienced a z20% volumetric reduction in their CNS lesions. Conclusions: This study confirms the modest CNS antitumor activity of lapatinib. Additional responses were observed with the combination of lapatinib and capecitabine. Further studies of lapatinib-based regimens for CNS metastases from HER2+ breast cancer are warranted.Brain metastases are diagnosed in approximately one third of women treated with trastuzumab for advanced HER2+ breast cancer (1 -5). The high incidence of HER2+ central nervous system (CNS) disease likely results from the inability of trastuzumab to cross the blood-brain barrier, in combination with a predilection of breast cancers that overexpress HER2 to metastasize to visceral sites, including the brain (6 -9). Despite initial therapy with whole-brain radiotherapy or stereotactic