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REVIEW article

Front. Oncol.
Sec. Breast Cancer
Volume 15 - 2025 | doi: 10.3389/fonc.2025.1530391
This article is part of the Research Topic Emerging Insights Related to Real-World Data Analysis in Breast Cancer Research View all articles

Real-world effectiveness of CDK4/6i in first-line treatment of HR+/HER2-advanced/metastatic breast cancer: Updated systematic review

Provisionally accepted
Nadia Harbeck Nadia Harbeck 1Adam Brufsky Adam Brufsky 2Chloe Grace Rose Chloe Grace Rose 3Beata Korytowsky Beata Korytowsky 3Connie Chen Connie Chen 3Krista Tantakoun Krista Tantakoun 4Endri Jazexhi Endri Jazexhi 4Do Hoang Vien Nguyen Do Hoang Vien Nguyen 4Meaghan Bartlett Meaghan Bartlett 4Imtiaz A. Samjoo Imtiaz A. Samjoo 4*Timothy Pluard Timothy Pluard 5x x x x 6
  • 1 Breast Center, Department of Gynecology & Obstetrics & Comprehensive Cancer Center Munich, LMU University Hospital, Munich, Germany
  • 2 UPMC Hillman Cancer Center, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
  • 3 Pfizer Inc., New York, NY, United States
  • 4 EVERSANA™, Burlington, Ontario, Canada
  • 5 St. Luke's Cancer Institute, Kansas City, MO, United States
  • 6 xxx, xxx, United States

The final, formatted version of the article will be published soon.

    Aim: Since 2021, additional real-world evidence (RWE) has emerged on the effectiveness of cyclindependent kinase 4/6 inhibitors (CDK4/6i) as first-line treatment of HR-positive/HER2-negative (HR+/HER2-) advanced/metastatic breast cancer (A/MBC), necessitating this updated review.Methods: MEDLINE®, Embase®, and Cochrane Databases (07/06/2019-01/09/2024), and key congresses (2020-2024) were searched. Studies reporting first-line CDK4/6i use, over 100 participants, and progression-free survival (PFS) and/or overall survival (OS) data were included.Results: This update included 82 unique studies, 42.7% for palbociclib, 7.3% for ribociclib, and 3.7% for abemaciclib; 46.3% assessed multiple CDK4/6i. In studies including multiple CDK4/6is, median PFS was 23.4-31.0 months for palbociclib, 19.8-44.0 for ribociclib, and 14.0-39.5 for abemaciclib.When reached, median OS was 38.0-58.0 months, 40.4-52.0 months, and 34.4 months, respectively. These real-world PFS and OS results were within the range of single-arm and CDK4/6i versus endocrine therapy (ET) studies, where CDK4/6i demonstrated greater benefits than ET alone.First-line CDK4/6i RWE demonstrates significant clinical benefits in HR+/HER2-A/MBC. These data are important to guide clinical decision-making, as they include patients who are not adequately represented in clinical trials. Studies with longer follow-up are needed to assess longterm benefits of all three CDK4/6i therapies in HR+/HER2-A/MBC.

    Keywords: CDK4/6 inhibitors, quality assessment, Breast, metastasis, Real-world evidence, Systematic Literature Review, HR+/HER2-

    Received: 18 Nov 2024; Accepted: 06 Feb 2025.

    Copyright: © 2025 Harbeck, Brufsky, Rose, Korytowsky, Chen, Tantakoun, Jazexhi, Nguyen, Bartlett, Samjoo, Pluard and x. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Imtiaz A. Samjoo, EVERSANA™, Burlington, Ontario, Canada

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.