Data from Overall Survival with Palbociclib and Fulvestrant in Women with HR+/HER2− ABC: Updated Exploratory Analyses of PALOMA-3, a Double-blind, Phase III Randomized Study
Year: 2023
Type: other
Abstract: Purpose: To conduct an updated exploratory analysis of overall survival (OS) with a longer median follow-up of 73.3 months and evaluate the prognostic value of molecular analysis by circulating tumor DNA (ctDNA). Patients and Methods: Patients with hormone receptor–positive/human epidermal growth factor receptor 2–negative (HR+/HER2−) advanced breast cancer (ABC) were randomized 2:1 to receive palbociclib (125 mg orally/day; 3/1 week schedule) and fulvestrant (500 mg intramuscularly) or placebo and fulvestrant. This OS analysis was performed when 75% of enrolled patients died (393 events in 521 randomized patients). ctDNA analysis was performed among patients who provided consent. Results: At the data cutoff (August 17, 2020), 258 and 135 deaths occurred in the palbociclib and placebo groups, respectively. The median OS [95% confidence interval (CI)] was 34.8 months (28.8–39.9) in the palbociclib group and 28.0 months (23.5–33.8) in the placebo group (stratified hazard ratio, 0.81; 95% CI, 0.65–0.99). The 6-year OS rate (95% CI) was 19.1% (14.9–23.7) and 12.9% (8.0–19.1) in the palbociclib and placebo groups, respectively. Favorable OS with palbociclib plus fulvestrant compared with placebo plus fulvestrant was observed in most subgroups, particularly in patients with endocrine-sensitive disease, no prior chemotherapy for ABC and low circulating tumor fraction and regardless of ESR1, PIK3CA, or TP53 mutation status. No new safety signals were identified. Conclusions: The clinically meaningful improvement in OS associated with palbociclib plus fulvestrant was maintained with >6 years of follow-up in patients with HR+/HER2− ABC, supporting palbociclib plus fulvestrant as a standard of care in these patients.
Authors: Massimo Cristofanilli, Hope S. Rugo, Seock-Ah Im, Dennis J. Slamon, Nadia Harbeck, Igor Bondarenko, Norikazu Masuda, Marco Colleoni, Angela DeMichele, Sherene Loi, Hiroji Iwata, Ben O'Leary, Fabrice André, Sibylle Loibl, Eustratios Bananis, Yuan Liu, Xin Huang, Sindy Kim, Maria Jose Lechuga Frean, Nicholas C. Turner
Institutions: Weill Cornell Medicine, University of California, San Francisco, UCSF Helen Diller Family Comprehensive Cancer Center, Seoul National University, Seoul National University Hospital, University of California, Los Angeles, LMU Klinikum, Ludwig-Maximilians-Universität München, Dnipro State Medical University, Nagoya University, European Institute of Oncology, Abramson Cancer Center, University of Pennsylvania, The University of Melbourne, Peter MacCallum Cancer Centre, Aichi Cancer Center Hospital, Institute of Cancer Research, Royal Marsden Hospital, Institut Gustave Roussy, German Breast Group, Pfizer (United States)
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Funder: Pfizer
OpenAlex ID: W4361950450