Efficacy of Subsequent Treatments After Disease Progression on CDK4/6 Inhibitors in Patients With Hormone Receptor-Positive Advanced Breast Cancer

Lis Victoria Ravani; Pedro Calomeni; Maysa Vilbert; Thiago Madeira; Ming Wang; Daxuan Deng; Laura Testa; Renata Colombo Bonadio; Katherine Clifton; Seth A Wander; Maryam Lustberg

doi:10.1200/OP-24-00649

Efficacy of Subsequent Treatments After Disease Progression on CDK4/6 Inhibitors in Patients With Hormone Receptor-Positive Advanced Breast Cancer

JCO Oncol Pract. 2024 Dec 17:OP2400649. doi: 10.1200/OP-24-00649. Online ahead of print.

Authors

Affiliations

¹ University of Sao Paulo Medical School, São Paulo, Brazil.
² Division of Hematology/Oncology, Department of Medicine, Massachusetts General Hospital Cancer Center, Massachusetts General Hospital, Boston, MA.
³ University of Minas Gerais Medical School, Minas Gerais, Brazil.
⁴ Department of Population and Quantitative Health Sciences, Case Western Reserve University School of Medicine, Cleveland, OH.
⁵ Department of Public Health Sciences, Penn State University College of Medicine, Hershey, PA.
⁶ Instituto do Câncer do Estado de São Paulo (ICESP), São Paulo, Brazil.
⁷ Washington University School of Medicine, St Louis, MO.
⁸ Medical Oncology, Yale Cancer Center, Yale University, New Haven, CT.

PMID: 39689274
DOI: 10.1200/OP-24-00649

Abstract

Purpose: Cyclin-dependent kinase 4/6 inhibitors (CDK4/6is) combined with endocrine therapy (ET) are the standard of care in hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer (aBC). Yet, disease progression remains common. In the absence of established postprogression sequencing guidelines, we conducted a pooled analysis of Kaplan-Meier (KM)-derived patient data to assess the efficacy of subsequent treatment options after disease progression on CDK4/6i therapy.

Methods: We conducted a systematic review and meta-analysis searching PubMed, Embase, Cochrane, and conference proceedings for randomized trials and cohort studies published from 2016 to December, 2023. Studies assessing subsequent treatment postprogression on CDK4/6i in patients with HR+ HER2- aBC were included. We performed a pooled analysis of KM-derived individual patient data. Outcomes of interest were progression-free survival (PFS) and overall survival (OS). This study is registered in PROSPERO, CRD42023491090.

Results: Of 12,895 identified records, 18 studies comprising 4,899 patients were included. Maintaining treatment with a CDK4/6i plus ET post-CDK4/6i progression was associated with longer PFS (hazard ratio [HR], 0.61 [95% CI, 0.53 to 0.70]; P < .01) and prolonged OS (HR, 0.68 [95% CI, 0.60 to 0.77]; P < .01) compared with ET monotherapy. The PFS benefit was seen in both continuing the previous CDK4/6i (HR, 0.67 [95% CI, 0.56 to 0.79]; P < .01) and switching to a different CDK4/6i (HR, 0.68 [95% CI, 0.54 to 0.85]; P < .01). Subsequent therapy with everolimus plus ET achieved similar PFS (HR, 1.10 [95% CI, 0.90 to 1.35]; P = .35) and significantly shorter OS (HR, 1.52; [95% CI, 1.21 to 1.90], P < .01) as compared with ET monotherapy.

Conclusion: This extensive data pool suggests significant benefit of CDK4/6i regimens after disease progression as compared with ET monotherapy. Our data also support current guideline recommendations of ET-based therapies over chemotherapy for treatment sequencing.