Trial reportBreast cancer research and treatment2017
IPET study: an FLT-PET window study to assess the activity of the steroid sulfatase inhibitor irosustat in early breast cancer.
Trial report in Breast cancer research and treatment, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 14 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.
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Who cites it
14 citing papers in PubMed, 28 citations in OpenAlex.
- Arylsulfamates inhibit colonic Bacteroidota growth through a sulfatase-independent mechanism.Proceedings of the National Academy of Sciences of the United States of America · 2025Article
- Targeting sex steroid biosynthesis for breast and prostate cancer therapy.Nature reviews. Cancer · 2023Review
- Characterising heart rhythm abnormalities associated with Xp22.31 deletion.Journal of medical genetics · 2023Article
- X-linked ichthyosis: New insights into a multi-system disorder.Skin health and disease · 2022Review
- Development of Sulfamoylated 4-(1-Phenyl-1Journal of medicinal chemistry · 2022Article
- New potent steroid sulphatase inhibitors based on 6-(1-phenyl-1Journal of enzyme inhibition and medicinal chemistry · 2021Article
- Article
- Steroid Sulphatase and Its Inhibitors: Past, Present, and Future.Molecules (Basel, Switzerland) · 2021Review
- Recent progress in the development of steroid sulphatase inhibitors - examples of the novel and most promising compounds from the last decade.Journal of enzyme inhibition and medicinal chemistry · 2020Review
- Article
- C-3- and C-4-Substituted Bicyclic Coumarin Sulfamates as Potent Steroid Sulfatase Inhibitors.ACS omega · 2018Article
- Imaging Tumor Proliferation in Breast Cancer: Current Update on Predictive Imaging Biomarkers.PET clinics · 2018Review
- In breast cancer subtypes steroid sulfatase (STS) is associated with less aggressive tumour characteristics.British journal of cancer · 2018Article
- Intracrine Regulation of Estrogen and Other Sex Steroid Levels in Endometrium and Non-gynecological Tissues; Pathology, Physiology, and Drug Discovery.Frontiers in pharmacology · 2018Review
Corrections and comments
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Authors and funding
14 authors at 5 institutions in 2 countries.
Funding
Abstract
backgroundSteroid sulfatase (STS) is involved in oestrogen biosynthesis and irosustat is a first generation, irreversible steroid sulfatase inhibitor. A pre-surgical window-of-opportunity study with irosustat was undertaken in estrogen receptor-positive (ER+) breast cancer to assess the effect of irosustat on tumour cell proliferation as measured by 3'-deoxy-3'-[18F] fluorothymidine uptake measured by PET scanning (FLT-PET) and Ki67.
methodsPostmenopausal women with untreated ER+ early breast cancer were recruited, and imaged with FLT-PET at baseline and after at least 2 weeks treatment with irosustat, 40 mg once daily orally. The primary endpoint was changed in FLT uptake; secondary endpoints included safety and tolerability of irosustat, changes in tumoral Ki67 and steroidogenic enzymes expression and circulating steroid hormone levels.
resultsThirteen women were recruited, and ten started irosustat for 2 weeks, followed by repeat FLT-PET scans in eight. Defining response as decreases of ≥20% in standardized uptake value (SUV) or ≥30% in Ki, 1 (12.5% (95% CI 2-47%, p = 0.001)) and 3 (43% (95% CI 16-75%, p = <0.001) patients, respectively, responded. 6 out of 7 patients had a Ki67 reduction (range = -19.3 to 76.4%), and median percentage difference in Ki67 was 52.3% (p = 0.028). In one patient with a low baseline STS expression, a 19.7% increase in Ki67 was recorded. STS decreases were seen in tumours with high basal STS expression, significant decreases were also noted in aromatase, and 17β-hydroxysteroid dehydrogenase type 1 and 2. Irosustat was generally well tolerated with all adverse event CTCAE Grade ≤2.
conclusionsIrosustat resulted in a significant reduction in FLT uptake and Ki67, and is well tolerated. These data are the first demonstrating clinical activity of irosustat in early breast cancer. Baseline expression of STS may be a biomarker of sensitivity to irosustat.
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