Nicholas C Turner1, Dennis J Slamon1, Jungsil Ro1, Igor Bondarenko1, Seock-Ah Im1, Norikazu Masuda1, Marco Colleoni1, Angela DeMichele1, Sherene Loi1, Sunil Verma1, Hiroji Iwata1, Nadia Harbeck1, Sibylle Loibl1, Fabrice André1, Kathy Puyana Theall1, Xin Huang1, Carla Giorgetti1, Cynthia Huang Bartlett1, Massimo Cristofanilli1. 1. From the Institute of Cancer Research and Royal Marsden Hospital, London (N.C.T.); David Geffen School of Medicine at University of California, Los Angeles, Santa Monica (D.J.S.), and Pfizer Oncology, San Diego (X.H.) - both in California; National Cancer Center, Goyang-si, Gyeonggi-do (J.R.), and Seoul National University Hospital, Cancer Research Institute, Seoul National University College of Medicine, Seoul (S.-A.I.) - both in South Korea; Dnipropetrovsk Medical Academy, City Multiple-Discipline Clinical Hospital 4, Dnipropetrovsk, Ukraine (I.B.); National Hospital Organization Osaka National Hospital, Osaka (N.M.), and Aichi Cancer Center Hospital, Nagoya (H.I.) - both in Japan; Istituto Europeo di Oncologia (M. Colleoni) and Pfizer Oncology (C.G.) - both in Milan; Abramson Cancer Center, University of Pennsylvania, Philadelphia (A.D.), and Pfizer Oncology, Collegeville (C.H.B.) - both in Pennsylvania; Peter MacCallum Cancer Centre, University of Melbourne, Melbourne, VIC, Australia (S. Loi); Tom Baker Cancer Centre, University of Calgary, Calgary, AB, Canada (S.V.); Brustzentrum der Universität München, Munich (N.H.), and the German Breast Group, Neu-Isenburg (S. Loibl) - both in Germany; Institut Gustave Roussy, Villejuif, France (F.A.); Pfizer Oncology, Cambridge, MA (K.P.T.); and the Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Feinberg School of Medicine, Chicago (M. Cristofanilli).
Abstract
BACKGROUND: The cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor palbociclib, in combination with fulvestrant therapy, prolongs progression-free survival among patients with hormone-receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer. We report the results of a prespecified analysis of overall survival. METHODS: We randomly assigned patients with hormone-receptor-positive, HER2-negative advanced breast cancer who had progression or relapse during previous endocrine therapy to receivepalbociclib plus fulvestrant or placebo plus fulvestrant. We analyzed overall survival; the effect of palbociclib according to the prespecified stratification factors of presence or absence of sensitivity to endocrine therapy, presence or absence of visceral metastatic disease, and menopausal status; the efficacy of subsequent therapies after disease progression; and safety. RESULTS: Among 521 patients who underwent randomization, the median overall survival was 34.9 months (95% confidence interval [CI], 28.8 to 40.0) in the palbociclib-fulvestrant group and 28.0 months (95% CI, 23.6 to 34.6) in the placebo-fulvestrant group (hazard ratio for death, 0.81; 95% CI, 0.64 to 1.03; P=0.09; absolute difference, 6.9 months). CDK4/6 inhibitor treatment after the completion of the trial regimen occurred in 16% of the patients in the placebo-fulvestrant group. Among 410 patients with sensitivity to previousendocrine therapy, the median overall survival was 39.7 months (95% CI, 34.8 to 45.7) in the palbociclib-fulvestrant group and 29.7 months (95% CI, 23.8 to 37.9) in the placebo-fulvestrant group (hazard ratio, 0.72; 95% CI, 0.55 to 0.94; absolute difference, 10.0 months). The median duration of subsequent therapy was similar in the two groups, and the median time to the receipt of chemotherapy was 17.6 months in the palbociclib-fulvestrant group, as compared with 8.8 months in the placebo-fulvestrant group (hazard ratio, 0.58; 95% CI, 0.47 to 0.73; P<0.001). No new safety signals were observed with 44.8 months of follow-up. CONCLUSIONS: Among patients with hormone-receptor-positive, HER2-negative advanced breast cancer who had sensitivity to previous endocrine therapy, treatment withpalbociclib-fulvestrant resulted in longer overall survival than treatment with placebo-fulvestrant. The differences in overall survival in the entire trial group were not significant. (Funded by Pfizer; PALOMA-3 ClinicalTrials.gov number, NCT01942135 .).
RCT Entities:
BACKGROUND: The cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor palbociclib, in combination with fulvestrant therapy, prolongs progression-free survival among patients with hormone-receptor-positive, humanepidermal growth factor receptor 2 (HER2)-negative advanced breast cancer. We report the results of a prespecified analysis of overall survival. METHODS: We randomly assigned patients with hormone-receptor-positive, HER2-negative advanced breast cancer who had progression or relapse during previous endocrine therapy to receive palbociclib plus fulvestrant or placebo plus fulvestrant. We analyzed overall survival; the effect of palbociclib according to the prespecified stratification factors of presence or absence of sensitivity to endocrine therapy, presence or absence of visceral metastatic disease, and menopausal status; the efficacy of subsequent therapies after disease progression; and safety. RESULTS: Among 521 patients who underwent randomization, the median overall survival was 34.9 months (95% confidence interval [CI], 28.8 to 40.0) in the palbociclib-fulvestrant group and 28.0 months (95% CI, 23.6 to 34.6) in the placebo-fulvestrant group (hazard ratio for death, 0.81; 95% CI, 0.64 to 1.03; P=0.09; absolute difference, 6.9 months). CDK4/6 inhibitor treatment after the completion of the trial regimen occurred in 16% of the patients in the placebo-fulvestrant group. Among 410 patients with sensitivity to previous endocrine therapy, the median overall survival was 39.7 months (95% CI, 34.8 to 45.7) in the palbociclib-fulvestrant group and 29.7 months (95% CI, 23.8 to 37.9) in the placebo-fulvestrant group (hazard ratio, 0.72; 95% CI, 0.55 to 0.94; absolute difference, 10.0 months). The median duration of subsequent therapy was similar in the two groups, and the median time to the receipt of chemotherapy was 17.6 months in the palbociclib-fulvestrant group, as compared with 8.8 months in the placebo-fulvestrant group (hazard ratio, 0.58; 95% CI, 0.47 to 0.73; P<0.001). No new safety signals were observed with 44.8 months of follow-up. CONCLUSIONS: Among patients with hormone-receptor-positive, HER2-negative advanced breast cancer who had sensitivity to previous endocrine therapy, treatment with palbociclib-fulvestrant resulted in longer overall survival than treatment with placebo-fulvestrant. The differences in overall survival in the entire trial group were not significant. (Funded by Pfizer; PALOMA-3 ClinicalTrials.gov number, NCT01942135 .).