Abemaciclib Plus a Nonsteroidal Aromatase Inhibitor as Initial Therapy for HR+/HER2-Advanced Breast Cancer:Interpretation of Final Overall Survival Results of MONARCH 3
MONARCH 3 is a randomized,double-blind,placebo-controlled phase Ⅲ study that enrolls women aged 18 years or older with postmenopausal,locally advanced,unresectable or metastatic hormone receptor positive/hu-man epidermal growth factor receptor 2 negative(HR+/HER2-)breast cancer without prior systemic therapy in the advanced setting.In summary,the MONARCH 3 study enrolled population was an advanced first-line treatment for endocrine-sensitive HR+/HER2-breast cancer.The patients were randomized in a 2∶1 ratio to receive Abemaciclib plus non-steroidal aromatase inhibitor(NSAI)or placebo plus NSAI treatment,with the primary endpoint being the investigator-assessed intention-to-treat(ITT)population's progression-free survival(PFS)and the secondary endpoint being overall survival(OS).Chemotherapy-free survival(CFS)was an exploratory endpoint.A total of 493 women were randomized in a 2∶1 ratio to receive Abemaciclib plus NSAI(Abemaciclib group,n=328)or placebo plus NSAI(placebo group,n=165).After a median follow-up of 8.1 years,there were 198 OS events(60.4％)in the Abemaci-clib arm and 116(70.3％)in the placebo arm(HR=0.804,95％CI:0.637～1.015,P=0.066 4).Median OS for Abe-maciclib and placebo was 66.8 months and 53.7 months,respectively.In the subgroup with visceral disease,there were 113(65.3％)OS events in the Abemaciclib arm and 65(72.2％)in the placebo arm(HR=0.758,95％CI:0.558～1.030,P=0.075 7).Median OS for Abemaciclib and placebo was 63.7 months and 48.8 months,respectively.No new safety signals were observed.Ultimately,OS did not achieve statistical significance,so achieving significant OS benefit in HR+/HER2-advanced breast cancer clinical trials may still face challenges.
NETL
NSTL
万方数据
