Year: 2025
Type: article
Abstract: BACKGROUND: Adjuvant abemaciclib combined with endocrine therapy (ET) significantly improved invasive disease-free survival (IDFS) in patients with hormone receptor (HR)-positive, human epidermal growth factor 2 (HER2)-negative, node-positive, high-risk early breast cancer (EBC). The impact on overall survival (OS) remained unknown. PATIENTS AND METHODS: In the phase III monarchE trial (NCT03155997), patients received ET for at least 5 years with or without abemaciclib for 2 years. In this article, we report the primary OS results, a key secondary endpoint, and updated estimates of IDFS and distant relapse-free survival (DRFS). RESULTS: Overall, 5637 patients underwent randomization, with 2808 assigned to abemaciclib-ET, and 2829 to ET. In the intent-to-treat population, with a median follow-up of 76.2 months, abemaciclib-ET resulted in a 15.8% lower risk of death than ET [661 deaths; hazard ratio 0.842, 95% confidence interval (CI) 0.722-0.981, P = 0.027], meeting the prespecified boundary for significance. The 7-year OS was 86.8% with abemaciclib-ET and 85.0% with ET (absolute difference, 1.8%). OS benefit was consistent across prespecified subgroups. In addition to patients who had already died of metastatic disease, fewer patients in the abemaciclib-ET arm were living with metastatic disease compared with the ET arm (6.4% versus 9.4%). Sustained improvement was demonstrated in IDFS and DRFS (hazard ratio 0.734, 95% CI 0.657-0.820 and hazard ratio 0.746, 95% CI 0.662-0.840, respectively). Seven-year IDFS was 77.4% with abemaciclib-ET and 70.9% with ET (absolute difference, 6.5%) and 7-year DRFS were 80.0% and 74.9% (absolute difference, 5.1%). The long-term safety data compiled did not support any concerns of delayed toxicities. CONCLUSIONS: Adjuvant abemaciclib-ET resulted in a statistically significant and clinically meaningful improvement in OS compared with ET in patients with HR-positive, HER2-negative, node-positive, high-risk EBC. At 7 years, abemaciclib-ET continued to demonstrate a sustained IDFS and DRFS benefit.
Source: Annals of Oncology
Authors: S. Johnston, M. Martin, J. O’Shaughnessy, R. Hegg, S.M. Tolaney, V. Guarneri, L. Del Mastro, M. Campone, J. Sohn, F. Boyle, J. Cortes, H.S. Rugo, M.P. Goetz, E.P. Hamilton, C.-S. Huang, E. Senkus, I. Cicin, L. Testa, P. Neven, J. Huober, Z. Shao, R. Wei, M. Munoz, B. San Antonio, A. Shahir, P. Rastogi, N. Harbeck
Institutions: Royal Marsden NHS Foundation Trust, Royal Marsden Hospital, Hospital General Universitario Gregorio Marañón, Centro de Investigación Biomédica en Red de Cáncer, GEICAM – Spanish Breast Cancer Group, Baylor University Medical Center, Universidade de São Paulo, Dana-Farber Cancer Institute, University of Padua, Istituto Oncologico Veneto, Ospedale Policlinico San Martino, University of Genoa, Centre National de la Recherche Scientifique, Inserm, Centre de Recherche en Cancérologie et Immunologie Intégrée Nantes Angers, Institut de Cancérologie de l'Ouest, Nantes Université, Yonsei University, The University of Sydney, IDCQ Hospitales y Sanidad, S.L.U., City Of Hope National Medical Center, University of California, San Francisco, UCSF Helen Diller Family Comprehensive Cancer Center, Mayo Clinic, Sarah Cannon, National Taiwan University Hospital, University Clinical Centre, Gdańsk Medical University, Istinye University, D’Or Institute for Research and Education, Universitair Ziekenhuis Leuven, Kantonsspital St. Gallen, Fudan University Shanghai Cancer Center, Eli Lilly (United States), UPMC Health System, UPMC Hillman Cancer Center, University of Pittsburgh Medical Center, NSABP Foundation, LMU Klinikum, Ludwig-Maximilians-Universität München
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $5,080
Funders: Bristol-Myers Squibb, Eli Lilly and Company, Pfizer, AstraZeneca, GlaxoSmithKline, Sanofi, Gilead Sciences, Ariad Pharmaceuticals, Celgene, Genomic Health, Helsinn, Queen Mary University of London, Baxalta, Exelixis, Jazz Pharmaceuticals, Royal Marsden NHS Foundation Trust, Les Laboratories Pierre Fabre, Clovis Oncology, Mylan, Mersana Therapeutics, BeiGene, Incyte, Carrick Therapeutics, Puma Biotechnology, G1 Therapeutics, Seagen, Natera, National Institute for Health and Care Research, Institute of Cancer Research, Eisai, Max-Planck-Gesellschaft, Servier, Ipsen, Aptitude Health, Genentech, Samsung, Helsinn Therapeutics, Chugai Pharmaceutical, Loxo Oncology, Daiichi Sankyo Europe
OpenAlex ID: W4415280900