ArticleNPJ breast cancer2022
A phase II trial of an alternative schedule of palbociclib and embedded serum TK1 analysis.
Article in NPJ breast cancer, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 12 papers.
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
12 citing papers in PubMed, 20 citations in OpenAlex.
- Trial
- Thymidine kinase activity levels in serum can identify HR+ metastatic breast cancer patients with a low risk of early progression (SWOG S0226).Biomarkers : biochemical indicators of exposure, response, and susceptibility to chemicals · 2023Trial
- Avutometinib, Abemaciclib, and Fulvestrant in Patients with HR+/HER2- Metastatic Breast Cancer Previously Treated with CDK4/6 Inhibitor: A Single-Arm Phase I Trial.Clinical cancer research : an official journal of the American Association for Cancer Research · 2026Article
- Prognostic role of thymidine kinase 1 activity in hormone receptor positive metastatic breast cancer. A systematic review and meta-analysis.Breast (Edinburgh, Scotland) · 2026Review
- The evolving landscape of CDK inhibitor use in breast cancer therapy and beyond.Nature reviews. Drug discovery · 2026Review
- Prognostic performance of thymidine kinase 1 activity in patients with hormone receptor-positive and HER2-negative metastatic breast cancer treated with CDK4/6 and aromatase inhibitors.Breast cancer research and treatment · 2026Observational
- Real-World Plasma Thymidine Kinase Activity in High-Risk and Metastatic Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer Treated With Cyclin-Dependent Kinase 4/6 Inhibitors.JCO precision oncology · 2026Observational
- Aberrant cytoplasmic localization of MLH1 characterizes a cell population that seeds breast cancer recurrence.Nature communications · 2025Article
- Thymidine kinase 1 concentration and activity in metastatic breast cancer under CDK4/6 inhibitor therapy.Scientific reports · 2025Article
- Phase I study of ribociclib (CDK4/6 inhibitor) with spartalizumab (PD-1 inhibitor) with and without fulvestrant in metastatic hormone receptor-positive breast cancer or advanced ovarian cancer.Journal for immunotherapy of cancer · 2025Article
- Genomic Complexity Predicts Resistance to Endocrine Therapy and CDK4/6 Inhibition in Hormone Receptor-Positive (HR+)/HER2-Negative Metastatic Breast Cancer.Clinical cancer research : an official journal of the American Association for Cancer Research · 2023Article
- The CDK4/6 Inhibitor Palbociclib Inhibits Estrogen-Positive and Triple Negative Breast Cancer Bone Metastasis In Vivo.Cancers · 2023Article
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 4 institutions in 2 countries.
Funding
Abstract
Palbociclib 3-weeks-on/1-week-off, combined with hormonal therapy, is approved for hormone receptor positive (HR+)/HER2-negative (HER2-) advanced/metastatic breast cancer (MBC). Neutropenia is the most frequent adverse event (AE). We aim to determine whether an alternative 5-days-on/2-days-off weekly schedule reduces grade 3 and above neutropenia (G3 + ANC) incidence. In this single-arm phase II trial, patients with HR+/HER2- MBC received palbociclib 125 mg, 5-days-on/2-days-off, plus letrozole or fulvestrant per physician, on a 28-day cycle (C), as their first- or second-line treatment. The primary endpoint was G3 + ANC in the first 29 days (C1). Secondary endpoints included AEs, efficacy, and serum thymidine kinase 1 (sTK1) activity. At data-cutoff, fifty-four patients received a median of 13 cycles (range 2.6-43.5). The rate of G3 + ANC was 21.3% (95% CI: 11.2-36.1%) without G4 in C1, and 40.7% (95% CI: 27.9-54.9%), including 38.9% G3 and 1.8% G4, in all cycles. The clinical benefit rate was 80.4% (95% CI: 66.5-89.7%). The median progression-free survival (mPFS) (95% CI) was 19.75 (12.11-34.89), 33.5 (17.25-not reached [NR]), and 11.96 (10.43-NR) months, in the overall, endocrine sensitive or resistant population, respectively. High sTK1 at baseline, C1 day 15 (C1D15), and C2D1 were independently prognostic for shorter PFS (p = 9.91 × 10
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.