Trial reportClinical cancer research : an official journal of the American Association for Cancer Research2022
Clinical Significance of PIK3CA and ESR1 Mutations in Circulating Tumor DNA: Analysis from the MONARCH 2 Study of Abemaciclib plus Fulvestrant.
Trial report in Clinical cancer research : an official journal of the American Association for Cancer Research, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 83 papers, 1 of them a synthesis 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
83 citing papers in PubMed, 1 synthesis or guideline pooled it, 98 citations in OpenAlex.
- PIK3CA mutation status, progression and survival in advanced HR + /HER2- breast cancer: a meta-analysis of published clinical trials.BMC cancer · 2022Pooled it
- Abemaciclib rechallenge after progression on abemaciclib plus endocrine therapy in patients with hormone receptor-positive HER2-negative metastatic breast cancer: results from the phase II again study (WJOG14220B).Breast cancer research and treatment · 2026Trial
- ctDNA and tumor-based biomarkers of giredestrant response in acelERA breast cancer.Nature communications · 2026Trial
- Trial
- Efficacy and safety of pyrotinib in patients with previously treated HER2-positive non-breast solid tumors: a phase 2, open-label basket trial.The oncologist · 2025Trial
- Continuous versus Standard Palbociclib Treatment and Molecular Profiling of Solid Tissues and Liquid Biopsies in the CCTG MA.38 Trial in Advanced Breast Cancer.Cancer research communications · 2025Trial
- Abemaciclib Plus Fulvestrant in Advanced Breast Cancer After Progression on CDK4/6 Inhibition: Results From the Phase III postMONARCH Trial.Journal of clinical oncology : official journal of the American Society of Clinical Oncology · 2025Trial
- Models of Early Resistance to CDK4/6 Inhibitors Unveil Potential Therapeutic Treatment Sequencing.International journal of molecular sciences · 2025Trial
- Elacestrant in ER+, HER2- Metastatic Breast Cancer with ESR1-Mutated Tumors: Subgroup Analyses from the Phase III EMERALD Trial by Prior Duration of Endocrine Therapy plus CDK4/6 Inhibitor and in Clinical Subgroups.Clinical cancer research : an official journal of the American Association for Cancer Research · 2024Trial
- Landscape of Baseline and Acquired Genomic Alterations in Circulating Tumor DNA with Abemaciclib Alone or with Endocrine Therapy in Advanced Breast Cancer.Clinical cancer research : an official journal of the American Association for Cancer Research · 2024Trial
- Mutational Analysis of Circulating Tumor DNA in Patients With Estrogen Receptor-Positive/Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer Receiving Palbociclib: Results From the TREnd Trial.JCO precision oncology · 2024Trial
- Clinical Efficacy and Whole-Exome Sequencing of Liquid Biopsies in a Phase IB/II Study of Bazedoxifene and Palbociclib in Advanced Hormone Receptor-Positive Breast Cancer.Clinical cancer research : an official journal of the American Association for Cancer Research · 2022Trial
- 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.Clinical cancer research : an official journal of the American Association for Cancer Research · 2022Trial
- Bridging Biomarker Testing to Biomarker-Driven Targeted Therapy: Real-World ESR1 Mutation Testing Patterns and Prevalence in ER+, HER2- Metastatic Breast Cancer.Molecular diagnosis & therapy · 2026Article
- Abemaciclib in HR+, HER2- Breast Cancer: A Narrative Review of the Clinical Evidence.Oncology and therapy · 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
- Emerging Strategies Targeting the PI3K/AKT/mTOR Pathway in HR+/HER2- Advanced Breast Cancer.Drugs · 2026Review
- New perspectives on endocrine therapy suitability for hormone receptor-positive metastatic breast cancer in clinical practice.Breast (Edinburgh, Scotland) · 2026Review
- Concordance analysis of non-invasive techniques for PIK3CA and ESR1 mutations in advanced HR+/HER2- breast cancer: the CANIPE study.NPJ precision oncology · 2026Article
- Navigating first- and second-line treatment options in hormone receptor-positive HER2-negative advanced breast cancer.The oncologist · 2026Review
23 more citing papers are in PubMed but not listed here.
Corrections and comments
- Erratum issued
Authors and funding
12 authors at 9 institutions in 5 countries.
Funding
Abstract
purposePIK3CA and ESR1 mutations have been implicated in resistance to endocrine therapy (ET) in HR+, HER2- advanced breast cancer (ABC). Inhibition of CDK4 and 6 has been hypothesized as a therapeutic strategy to overcome endocrine resistance in patients with PIK3CA- or ESR1-mutant breast cancers. The objective of this exploratory analysis was to assess efficacy of abemaciclib plus fulvestrant in patients with or without PIK3CA or ESR1 mutations in MONARCH 2. PATIENTS AND
methodsMONARCH 2 was a global, randomized, double-blind phase III trial of abemaciclib plus fulvestrant in 669 women with HR+, HER2- ABC, which had progressed on ET. Patients were randomized 2:1 to receive abemaciclib plus fulvestrant or placebo plus fulvestrant. Exploratory analyses assessed progression-free survival (PFS) and overall survival (OS), and other endpoints, in patients with or without PIK3CA or ESR1 mutations detectable in baseline ctDNA.
resultsFrom the MONARCH 2 population, 219 and 248 patient samples were successfully analyzed for either PIK3CA or ESR1 mutations, respectively. Abemaciclib plus fulvestrant improved PFS compared with placebo plus fulvestrant in both PIK3CA-wild-type (median 16.9 months vs. 12.3 months; HR, 0.51; 95% CI, 0.33-0.78) and PIK3CA-mutant subgroups (median 17.1 months vs. 5.7 months; HR, 0.53; 95% CI, 0.33-0.84), as well as both ESR1-wild-type (median 15.3 months vs. 11.2 months; HR, 0.44; 95% CI, 0.27-0.71) and ESR1-mutant subgroups (median 20.7 months vs. 13.1 months; HR, 0.54; 95% CI, 0.37-0.79). Additional endpoints, including OS, were also improved following treatment with abemaciclib plus fulvestrant regardless of PIK3CA or ESR1 mutation status.
conclusionsAbemaciclib plus fulvestrant was effective regardless of PIK3CA or ESR1 mutation status, with benefit in both PFS and OS, with a numerically greater improvement in median PFS relative to placebo plus fulvestrant for PIK3CA- or ESR1-mutant tumors compared with the respective wild-type subgroups, in women with HR+, HER2- ABC that had progressed on ET.
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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 OpenQuestion graph.