Trial reportJournal of clinical oncology : official journal of the American Society of Clinical Oncology2025
Abemaciclib Plus Fulvestrant in Advanced Breast Cancer After Progression on CDK4/6 Inhibition: Results From the Phase III postMONARCH Trial.
Trial report in Journal of clinical oncology : official journal of the American Society of Clinical Oncology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 65 papers, 6 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
65 citing papers in PubMed, 6 syntheses or guidelines pooled it.
- CDK4/6 inhibitors combined with fulvestrant for the treatment of HR+/HER2-advanced or metastatic breast cancer: a Bayesian network meta-analysis.BMC cancer · 2026Pooled it
- Guidance for Canadian Breast Cancer Practice: National Consensus Recommendations for the Systemic Treatment of Patients with HR+/HER2- Metastatic Breast Cancer 2025.Current oncology (Toronto, Ont.) · 2026Guideline
- The Role of Estrogen Receptor-Targeted PET with 16α-Journal of nuclear medicine : official publication, Society of Nuclear Medicine · 2026Pooled it
- Comparative efficacy of first- versus second-line CDK4/6 inhibition in hormone receptor-positive, HER2-negative metastatic breast cancer.Breast cancer research : BCR · 2025Pooled it
- Systematic Review and Network Meta-Analysis on Treating Hormone Receptor-Positive Metastatic Breast Cancer After CDK4/6 Inhibitors.Current oncology (Toronto, Ont.) · 2025Pooled it
- Comparative long-term outcomes of first-line CDK4/6 inhibitors plus endocrine therapy versus endocrine therapy in patients with HR+/HER2-metastatic or advanced breast cancer: a meta-analysis.Frontiers in pharmacology · 2025Pooled it
- Trial
- Models of Early Resistance to CDK4/6 Inhibitors Unveil Potential Therapeutic Treatment Sequencing.International journal of molecular sciences · 2025Trial
- CDK4/6 Inhibitors in Breast Cancer Therapy: Mechanisms, Resistance, and Emerging Opportunities.Targeted oncology · 2026Review
- WITHDRAWN: From CDK4/6 to CDK2 and KAT: Evolving therapeutic approaches in HR+/HER2- breast cancer.Breast (Edinburgh, Scotland) · 2026Article
- Emerging Strategies Targeting the PI3K/AKT/mTOR Pathway in HR+/HER2- Advanced Breast Cancer.Drugs · 2026Review
- Review
- Evolving First-Line Endocrine Therapy in HR+/HER2- Metastatic Breast Cancer: CDK4/6 Inhibition, Biomarker-Guided Strategies and Emerging Therapeutic Paradigms.Current oncology (Toronto, Ont.) · 2026Review
- CDK4/6 Inhibitor-Induced Senescence in Cancer: Mechanisms and Therapeutic Implications.Cancers · 2026Review
- Navigating first- and second-line treatment options in hormone receptor-positive HER2-negative advanced breast cancer.The oncologist · 2026Review
- Abemaciclib plus endocrine therapy in chemotherapy-treated patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer.Breast cancer (Tokyo, Japan) · 2026Article
- The evolving landscape of CDK inhibitor use in breast cancer therapy and beyond.Nature reviews. Drug discovery · 2026Review
- Abemaciclib in HR+, HER2- Breast Cancer: A Narrative Review of the Clinical Evidence.Oncology and therapy · 2026Review
- Post-CDK4/6 Inhibitor Therapeutic Approaches in Hormone Receptor-Positive, HER2-Negative Metastatic Breast Cancer: Current Evidence and Emerging Strategies-A Narrative Review.Diagnostics (Basel, Switzerland) · 2026Review
- Time-resolved proteomic and phosphoproteomic analysis reveals convergent and divergent biological perturbations induced by FDA-approved CDK4/6 inhibitors in hormone receptor-positive breast cancers.Acta pharmacologica Sinica · 2026Article
5 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
23 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
purposeCyclin-dependent kinase 4/6 inhibitors (CDK4/6i) combined with endocrine therapy (ET) are the standard first-line treatment for hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC); however, disease progression occurs in almost all patients and additional treatment options are needed. Herein, we report outcomes of the postMONARCH trial investigating a switch in ET with/without CDK4/6 inhibition with abemaciclib after disease progression on CDK4/6i.
methodsThis double-blind, randomized phase III study enrolled patients with disease progression on previous CDK4/6i plus aromatase inhibitor as initial therapy for advanced disease or recurrence on/after adjuvant CDK4/6i + ET. Patients were randomly assigned (1:1) to abemaciclib + fulvestrant or placebo + fulvestrant. The primary end point was investigator-assessed progression-free survival (PFS). Secondary end points included PFS by blinded independent central review, objective response rate (ORR), and safety.
resultsThis study randomly assigned 368 patients (abemaciclib + fulvestrant, n = 182 placebo + fulvestrant, n = 186). At the primary analysis (258 events), the hazard ratio (HR) was 0.73 (95% CI, 0.57 to 0.95; nominal
conclusionAbemaciclib + fulvestrant significantly improved PFS after disease progression on previous CDK4/6i + ET in patients with HR+, HER2- ABC, offering an additional targeted therapy option for these patients.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.