Lapatinib plus capecitabine in treating HER2-positive advanced breast cancer:efficacy,safety,and biomarker results from Chinese patients

摘要

Overexpression of human epidermal growth factor receptor-2(HER2) in metastatic breast cancer(MBC) is associated with poor prognosis.This single-arm open-label trial(EGF109491;NCT00508274) was designed to confirm the efficacy and safety of lapatinib in combination with capecitabine in 52 heavily pretreated Chinese patients with HER2-positive MBC.The primary endpoint was clinical benefit rate(CBR).Secondary endpoints included progression-free survival(PFS),time to response(TTR),duration of response(DoR),central nervous system(CNS) as first site of relapse,and safety.The results showed that there were 23 patients with partial responses and 7 patients with stable disease,resulting in a CBR of 57.7%.The median PFS was 6.34 months(95% confidence interval,4.93-9.82 months).The median TTR and DoR were 4.07 months(range,0.03-14.78 months) and 6.93 months(range,1.45-9.72 months),respectively.Thirteen(25.0%) patients had new lesions as disease progression.Among them,2(3.8%) patients had CNS disease reported as the first relapse.The most common toxicities were palmar-plantar erythrodysesthesia(59.6%),diarrhea(48.1%),rash(48.1%),hyperbilirubinemia(34.6%),and fatigue(30.8%).Exploratory analyses of oncogenic mutations of PIK3CA suggested that of 38 patients providing a tumor sample,baseline PIK3CA mutation status was not associated with CBR(P = 0.639) or PFS(P = 0.989).These data confirm that the lapatinib plus capecitabine combination is an effective and well-tolerated treatment option for Chinese women with heavily pretreated MBC,irrespective of PIK3CA status.