Trial reportEuropean journal of cancer (Oxford, England : 1990)2021
Phase I/II trial of palbociclib, pembrolizumab and letrozole in patients with hormone receptor-positive metastatic breast cancer.
Trial report in European journal of cancer (Oxford, England : 1990), 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 65 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
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, 1 synthesis or guideline pooled it, 83 citations in OpenAlex.
- CDK4/6 inhibitors as conditional immune-priming agents in breast cancer: therapeutic windows, sequencing strategies, and rational combinations with immunotherapy, radiotherapy, and antibody-drug conjugates.Frontiers in immunology · 2026Pooled it
- Hormone therapy enhances anti-PD1 efficacy in premenopausal estrogen receptor-positive and HER2-negative advanced breast cancer.Cell reports. Medicine · 2025Trial
- Efficacy, safety, and biomarker analysis of nivolumab in combination with abemaciclib plus endocrine therapy in patients with HR-positive HER2-negative metastatic breast cancer: a phase II study (WJOG11418B NEWFLAME trial).Journal for immunotherapy of cancer · 2023Trial
- CDK4/6 Inhibitors in Breast Cancer Therapy: Mechanisms, Resistance, and Emerging Opportunities.Targeted oncology · 2026Review
- Therapeutic challenges of a renal collision tumour comprising clear cell renal cell carcinoma and metastatic breast carcinoma: a case report.BJC reports · 2026Article
- RRM2 as a biomarker and therapeutic target in letrozole resistant estrogen receptor positive breast cancer.Scientific reports · 2026Article
- Advances in Immunotherapy for Breast Cancer.Oncology (Williston Park, N.Y.) · 2026Review
- Favorable outcome of immunotherapy use in metastatic HR+/HER2- breast cancer: a population-based cohort study.International journal of surgery (London, England) · 2026Article
- Immune Checkpoint Blockade and Emerging Combination Platforms in Breast Cancer: A Narrative Review.Breast cancer (Dove Medical Press) · 2026Review
- Emerging Targeted and Multimodal Therapeutic Strategies in Breast Cancer: A Comprehensive Review.Breast cancer (Dove Medical Press) · 2026Review
- Cyclin-dependent kinase 4 and 6 inhibitors and the breast cancer immune ecosystem: immune remodeling, resistance, and therapeutic reprogramming.Frontiers in immunology · 2026Review
- Immune Checkpoint Inhibitor Therapy in Hormone Receptor-Positive Breast Cancer.International journal of molecular sciences · 2025Review
- The Dual Effects of CDK4/6 Inhibitors on Tumor Immunity.Cancers · 2025Review
- A narrative review of therapy-induced senescence in cancer: mechanisms, immune interplay, and therapeutic opportunities.Journal of the Egyptian National Cancer Institute · 2025Review
- Demographic and clinical insights into Stage IV breast cancer: a comparative approach to surgical versus non-surgical treatment outcomes.Annals of medicine and surgery (2012) · 2025Article
- Selective CDK4 inhibition holds promise for breast cancer.Cell research · 2025Article
- IL-17A-secreting γδ T cells promote resistance to CDK4/CDK6 inhibitors in HRNature cancer · 2025Article
- Unlocking the Potential of Immune Checkpoint Inhibitors in HR+/HER2- Breast Cancer: A Systematic Review.Cancers · 2025Review
- Efficacy and Predictability of Cyclin-Dependent Kinase 4/6 Inhibitors in HER2-Positive Breast Cancer.Cancers · 2025Review
- The landscape of cyclin-dependent kinase 4/6 inhibitors in solid malignancies: emphasis on immunotherapy combinatorial strategies.Medical oncology (Northwood, London, England) · 2025Review
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
19 authors at 1 institution in 1 country.
Funding
Abstract
backgroundCDK4/6 inhibitors modulate immune response in breast cancer. This phase I/II trial was designed to test the safety and efficacy of palbociclib, pembrolizumab and letrozole in women with hormone receptor positive (HR PATIENTS AND
methodsWomen with stage IV HR
resultsBetween November 2016 and July 2020, 23 patients were enrolled with 20 evaluable for response, including 4 patients in cohort 1 and 16 patients in cohort 2. Cohort 1 median age was 48 years (33-70) and cohort 2 median age was 55 (37-75). Cohort 1 closed early due to limited accrual. Grade III-IV adverse events were neutropenia (83%), leucopaenia (65%), thrombocytopenia (17%) and elevated liver enzymes (17%). In cohort 1, 50% achieved a partial response (PR) and 50% had stable disease (SD). In cohort 2, 31% achieved complete response (CR), 25% had PR and 31% had SD by Response Evaluation Criteria in Solid Tumours version 1.1. Median progression-free survival was 25.2 months (95% confidence interval [CI] 5.3, not reached) and median overall survival was 36.9 months (95% CI 36.9, not reached) in cohort 2 with a median follow-up of 24.8 months (95% CI 17.1, not reached). A correlative immune biomarker analysis was published separately.
conclusionThe combination of palbociclib, pembrolizumab and letrozole is well tolerated, and a complete response rate of 31% was identified in HR
Indexed as
Identifiers
What OpenQuestion holds
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 OpenQuestion graph.