Trial reportBritish journal of clinical pharmacology2016
Fulvestrant decreases anastrozole drug concentrations when taken concurrently by patients with metastatic breast cancer treated on SWOG study S0226.
Trial report in British journal of clinical pharmacology, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers.
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
6 citing papers in PubMed, 14 citations in OpenAlex.
- Fulvestrant decreases anastrozole drug concentrations when taken concurrently by patients with metastatic breast cancer treated on SWOG study S0226.British journal of clinical pharmacology · 2016Trial
- Effects ofPharmacogenomics · 2023Article
- Fulvestrant in the treatment of hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer: A review.Cancer medicine · 2019Review
- Germline genetic predictors of aromatase inhibitor concentrations, estrogen suppression and drug efficacy and toxicity in breast cancer patients.Pharmacogenomics · 2017Review
- Polymorphisms in ABCB1 and CYP19A1 genes affect anastrozole plasma concentrations and clinical outcomes in postmenopausal breast cancer patients.British journal of clinical pharmacology · 2017Article
- Metastatic breast cancer: Endocrine therapy landscape reshaped.Avicenna journal of medicineReview
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
13 authors at 11 institutions in 2 countries.
Funding
Abstract
aimsIn the SWOG S0226 trial the combination of anastrozole plus fulvestrant (n = 349) was superior to anastrozole alone (n = 345) in hormone receptor (HR)-positive metastatic breast cancer. Here we report a pharmacokinetic subset analysis investigating a possible drug interaction between anastrozole and fulvestrant.
methodsPost-menopausal patients with HR-positive metastatic breast cancer were randomized to anastrozole with or without concurrent fulvestrant. Blood samples were collected at 2, 4, 6 and 8 months, just prior to receiving the next dose of anastrozole and fulvestrant. Drug concentrations were measured via LC/MS-MS. Anastrozole concentration was compared in patients on anastrozole alone vs. patients on concomitant fulvestrant. Comparisons were made at each time point using parametric tests and over time using a linear mixed effects model.
resultsA total of 483 anastrozole concentration measurements were included, 224 samples from 64 patients on the anastrozole alone arm and 259 from 73 patients on the combination arm. The mean anastrozole concentration in the combination arm was significantly lower than that in the anastrozole alone arm at each sample collection time (all P < 0.01) and in the mixed effects model (an estimated difference of 9.85 ng ml(-1) (95% CI 5.69, 14.00 ng ml(-1) ), P < 0.001).
conclusionA significant pharmacokinetic drug interaction was detected, in which the addition of fulvestrant to anastrozole treatment decreased the trough anastrozole concentration. Further research is needed to verify whether this interaction affects treatment efficacy and to determine the pharmacological mechanism by which this interaction occurs.
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Registered trials
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