CClinicalTrials.gg
Status unknownNCT05133674Updated May 25, 2022

Therapeutic Dose Monitoring (TDM) of Tamoxifen

A Phase 2 interventional study of Tamoxifen 20 mg in Breast Cancer, Breast Carcinoma and Breast Tumors, sponsored by Karolinska University Hospital. Status unknown at 1 site in Sweden. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2022-05-25.

Sponsored by Karolinska University Hospital · Phase 2, Interventional, and Treatment

The sponsor has not verified this record recently (last verified May 2022), so the status shown — last known as Active, not recruiting — may be out of date.
Phase
Phase 2
Study type
Interventional
Enrollment
40
Allocation
Not applicable
Ages
18 Years and older
Sex
Female
01

Study summary

Tamoxifen is a potent and effective drug reducing the risk of dying from breast cancer in the adjuvant setting. Although more modern drugs have partly replaced tamoxifen, it is helpful in the neoadjuvant and metastatic settings as a single drug. Despite that, in the adjuvant setting, it is a valuable drug.

This study aims to validate and study the feasibility of serial assessments, including therapeutic drug monitoring of tamoxifen, 4-hydroxytamoxifen and Z-endoxifen by capillary blood sampling, combined with patient-reported symptom scores. This will provide preliminary data to allow us to develop a future multicentre randomised clinical trial of personalised dose monitoring and adjustment of adjuvant tamoxifen therapy to enhance the quality of life and breast cancer outcomes.

Read the detailed description

This repeated-measures, prospective, open-label, single-centre study is designed for women with stage 0-3 breast cancer receiving adjuvant tamoxifen 20 mg/day.

Inclusion criteria:

  1. Female patients aged ≥ 18 years with hormone-positive stage 0-3 breast cancer.
  2. Performance status Eastern Cooperative Oncology Group (ECOG) 0-2.
  3. Ongoing daily adjuvant tamoxifen minimum of 2 months ± gonadotropin-releasing hormone (GnRH) analogues ± radiation therapy (RT) for stage 3 breast cancer.
  4. Locally recurrent disease, previously treated with adjuvant tamoxifen.
  5. Able to use software applications developed specifically for small, wireless computing devices, such as smartphones and tablets.
  6. Have small, wireless computing devices, such as smartphones and tablets.

Exclusion Criteria:

  1. Fulfilling any of the contraindications for tamoxifen.
  2. Metastatic (stage IV) breast cancer.
  3. Included in other clinical studies receiving not approved investigational medicinal drug.
  4. Ongoing pregnancy or lactation.
  5. Any psychological, familial, sociological, or geographical condition potentially hampering compliance with the study protocol and follow-up schedule.

No. Of Subjects: 40 female subjects.

Measured components: Tamoxifen, 4-hydroxytamoxifen and Z-endoxifen

Study design: Blood samples for measurement of tamoxifen, 4-hydroxytamoxifen and Z-endoxifen will be drawn capillary in total at 4-time points, at inclusion (baseline), and after 1, 2, and 3 weeks for each participant; and venously in total at 2-time points, at inclusion (baseline), and after 3 weeks for each participant.

At each time, participants will be asked to leave 2 vials of capillary blood (50ul x2) using the rhelise™ kit and 2 samples of conventional venous blood for blood and plasma (5 ml x 2).

02

Conditions studied

  • Breast Cancer
  • Breast Carcinoma
  • Breast Tumors
  • Cancer of Breast
  • Malignant Neoplasm of Breast

Keywords

  • Adjuvant Tamoxifen
  • Endoxifen
  • Patient reported outcomes
  • Adjuvant endocrine treatment
  • Selective Estrogen Receptor Modulators
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In context

Breast Neoplasms

12,544 studies on the registry are indexed under Breast Neoplasms; 2,892 are open to participants now.

This study's enrollment of 40 is below the median of 72 across 9,303 interventional studies indexed under Breast Neoplasms.

Browse Breast Neoplasms studies →

Lead sponsor

Karolinska University Hospital is the lead sponsor of 275 studies on the registry; 54 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
Female
Accepts healthy volunteers
No

Inclusion criteria

  1. Female patients aged ≥ 18 years with hormone-positive stage 0-3 breast cancer.
  2. Performance status ECOG 0-2.
  3. Ongoing daily adjuvant tamoxifen minimum of 2 months ± GnRH analogues ± RT for stage 3 breast cancer.
  4. Locally recurrent disease, previously treated with adjuvant tamoxifen.
  5. Able to use software applications developed specifically for small, wireless computing devices, such as smartphones and tablets.
  6. Have small, wireless computing devices, such as smartphones and tablets.

Exclusion criteria

Exclusion Criteria:

  1. Fulfilling any of the contraindications for tamoxifen.
  2. Metastatic (stage IV) breast cancer.
  3. Included in other clinical studies receiving not approved investigational medicinal drug.
  4. Ongoing pregnancy or lactation.
  5. Any psychological, familial, sociological, or geographical condition potentially hampering compliance with the study protocol and follow-up schedule.
05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
40 participants (actual)

Study arms

  • Experimental
    0

    Blood concentrations of tamoxifen, 4-hydroxytamoxifen and Z-endoxifen will be measured.

    Drug: Tamoxifen 20 mg

Interventions

  • DrugTamoxifen 20 mg

    i) a self-testing capillary kit, the rhelise™ kit for measuring the concentrations of tamoxifen, 4-hydroxytamoxifen and Z-endoxifen and ii) a patient interactive digital tool (app) mBraze to collect data about symptoms and guide breast cancer patients on adjuvant tamoxifen.

06

What researchers measure

Primary outcomes

  1. To validate the rhelise™ kit for monitoring tamoxifen, 4-hydroxytamoxifen and Z-endoxifen among patients recommended or who have ongoing adjuvant tamoxifen.

    Blood concentrations of tamoxifen, 4-hydroxytamoxifen and Z-endoxifen at baseline, two weeks, 1, 2, and 3 weeks by capillary and venous blood sampling (whole blood/plasma).

    Time frame: At at inclusion (baseline) for each participant.

  2. To validate the rhelise™ kit for monitoring tamoxifen, 4-hydroxytamoxifen and Z-endoxifen among patients recommended or who have ongoing adjuvant tamoxifen.

    Blood concentrations of tamoxifen, 4-hydroxytamoxifen and Z-endoxifen at baseline, two weeks, 1, 2, and 3 weeks by capillary and venous blood sampling (whole blood/plasma).

    Time frame: At week 3 after inclusion for each participant.

Secondary outcomes

  1. To test the correlations of concentrations found in the capillary sample (rhelise™ kit) and the venous blood sample (gold standard).

    Correlations of blood concentrations of tamoxifen, 4-hydroxytamoxifen and Z-endoxifen between venous blood samples and capillary blood samples (Sensitivity and specificity).

    Time frame: At 4-time points, at inclusion (baseline), and after 1, 2, and 3 weeks for each participant.

  2. To validate user acceptability and feasibility of self-testing the capillary kit.

    Capillary blood test concentrations of tamoxifen, 4-hydroxytamoxifen and Z-endoxifen were taken by the patient and the research nurse.

    Time frame: At 4-time points, at inclusion (baseline), and after 1, 2, and 3 weeks for each participant.

  3. Symptom distresses scores measured by the patient interactive digital tool (application) mBraze.

    Time frame: at baseline and 3 weeks.

  4. To compare and correlate blood concentrations of tamoxifen, 4-hydroxytamoxifen and Z-endoxifen with patient-reported outcome measures and the application mBraze for symptom self-monitoring.

    Correlations between tamoxifen, 4-hydroxytamoxifen and Z-endoxifen concentrations and symptom distress score ((fatigue, insomnia, pain, body image, and systemic therapy side-effect and cognitive-, emotional-, role-, sexual and social functioning). Correlations between tamoxifen, 4-hydroxytamoxifen and Z-endoxifen concentrations and symptom distress in the same patient.

    Time frame: at baseline and 3 weeks

  5. To validate the user experience of the mBraze app.

    - The interview on user acceptability and attitudes toward mBraze.

    Time frame: at 3 weeks.

  6. To validate the usability of the mBraze app.

    - Self-reported usability and user experience of the mBraze app measured with system usability scale (SUS).

    Time frame: at 3 weeks.

  7. To determine user acceptability and attitudes toward self-testing.

    - The interview on user acceptability and attitudes toward self-testing.

    Time frame: at 3 weeks.

07

Study locations

1 site
  • Karolinska University Hospital
    Stockholm, 171 76, Sweden
08

References and documents

Publications

  • Early Breast Cancer Trialists' Collaborative Group (EBCTCG); Davies C, Godwin J, Gray R, Clarke M, Cutter D, Darby S, McGale P, Pan HC, Taylor C, Wang YC, Dowsett M, Ingle J, Peto R. Relevance of breast cancer hormone receptors and other factors to the efficacy of adjuvant tamoxifen: patient-level meta-analysis of randomised trials. Lancet. 2011 Aug 27;378(9793):771-84. doi: 10.1016/S0140-6736(11)60993-8. Epub 2011 Jul 28. PubMed 21802721 ↗
  • Early Breast Cancer Trialists' Collaborative Group (EBCTCG). Aromatase inhibitors versus tamoxifen in early breast cancer: patient-level meta-analysis of the randomised trials. Lancet. 2015 Oct 3;386(10001):1341-1352. doi: 10.1016/S0140-6736(15)61074-1. Epub 2015 Jul 23. PubMed 26211827 ↗
  • Eriksson M, Eklund M, Borgquist S, Hellgren R, Margolin S, Thoren L, Rosendahl A, Lang K, Tapia J, Backlund M, Discacciati A, Crippa A, Gabrielson M, Hammarstrom M, Wengstrom Y, Czene K, Hall P. Low-Dose Tamoxifen for Mammographic Density Reduction: A Randomized Controlled Trial. J Clin Oncol. 2021 Jun 10;39(17):1899-1908. doi: 10.1200/JCO.20.02598. Epub 2021 Mar 18. PubMed 33734864 ↗
  • He W, Fang F, Varnum C, Eriksson M, Hall P, Czene K. Predictors of Discontinuation of Adjuvant Hormone Therapy in Patients With Breast Cancer. J Clin Oncol. 2015 Jul 10;33(20):2262-9. doi: 10.1200/JCO.2014.59.3673. Epub 2015 Jun 1. PubMed 26033800 ↗
  • Madlensky L, Natarajan L, Tchu S, Pu M, Mortimer J, Flatt SW, Nikoloff DM, Hillman G, Fontecha MR, Lawrence HJ, Parker BA, Wu AH, Pierce JP. Tamoxifen metabolite concentrations, CYP2D6 genotype, and breast cancer outcomes. Clin Pharmacol Ther. 2011 May;89(5):718-25. doi: 10.1038/clpt.2011.32. Epub 2011 Mar 23. PubMed 21430657 ↗
  • Fabian CJ. Will a Low-Dose Option Improve Uptake of Tamoxifen for Breast Cancer Risk Reduction? J Clin Oncol. 2019 Jul 1;37(19):1595-1597. doi: 10.1200/JCO.19.00656. Epub 2019 May 13. No abstract available. PubMed 31082270 ↗
  • Smith SG, Sestak I, Forster A, Partridge A, Side L, Wolf MS, Horne R, Wardle J, Cuzick J. Factors affecting uptake and adherence to breast cancer chemoprevention: a systematic review and meta-analysis. Ann Oncol. 2016 Apr;27(4):575-90. doi: 10.1093/annonc/mdv590. Epub 2015 Dec 8. PubMed 26646754 ↗
  • Thoren L, Lindh JD, Ackehed G, Kringen MK, Hall P, Bergh J, Molden E, Margolin S, Eliasson E. Impairment of endoxifen formation in tamoxifen-treated premenopausal breast cancer patients carrying reduced-function CYP2D6 alleles. Br J Clin Pharmacol. 2021 Mar;87(3):1243-1252. doi: 10.1111/bcp.14500. Epub 2020 Aug 9. PubMed 32713032 ↗
  • Borges S, Desta Z, Li L, Skaar TC, Ward BA, Nguyen A, Jin Y, Storniolo AM, Nikoloff DM, Wu L, Hillman G, Hayes DF, Stearns V, Flockhart DA. Quantitative effect of CYP2D6 genotype and inhibitors on tamoxifen metabolism: implication for optimization of breast cancer treatment. Clin Pharmacol Ther. 2006 Jul;80(1):61-74. doi: 10.1016/j.clpt.2006.03.013. PubMed 16815318 ↗
  • Jin Y, Desta Z, Stearns V, Ward B, Ho H, Lee KH, Skaar T, Storniolo AM, Li L, Araba A, Blanchard R, Nguyen A, Ullmer L, Hayden J, Lemler S, Weinshilboum RM, Rae JM, Hayes DF, Flockhart DA. CYP2D6 genotype, antidepressant use, and tamoxifen metabolism during adjuvant breast cancer treatment. J Natl Cancer Inst. 2005 Jan 5;97(1):30-9. doi: 10.1093/jnci/dji005. PubMed 15632378 ↗
  • Ferraldeschi R, Newman WG. The Impact of CYP2D6 Genotyping on Tamoxifen Treatment. Pharmaceuticals (Basel). 2010 Apr 15;3(4):1122-1138. doi: 10.3390/ph3041122. PubMed 27713292 ↗
  • Cronin-Fenton DP, Damkier P. Tamoxifen and CYP2D6: A Controversy in Pharmacogenetics. Adv Pharmacol. 2018;83:65-91. doi: 10.1016/bs.apha.2018.03.001. Epub 2018 May 7. PubMed 29801584 ↗
  • Sanchez-Spitman AB, Swen JJ, Dezentje VO, Moes DJAR, Gelderblom H, Guchelaar HJ. Effect of CYP2C19 genotypes on tamoxifen metabolism and early-breast cancer relapse. Sci Rep. 2021 Jan 11;11(1):415. doi: 10.1038/s41598-020-79972-x. PubMed 33432065 ↗
  • Bergqvist J, Lundstrom S, Wengstrom Y. Patient interactive digital support for women with adjuvant endocrine therapy in order to increase compliance and quality of life. Support Care Cancer. 2021 Jan;29(1):491-497. doi: 10.1007/s00520-020-05476-z. Epub 2020 May 13. PubMed 32405965 ↗

Individual participant data

Plan to share: No

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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on May 25, 2022, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT05133674
Lead sponsor
Karolinska University Hospital
Responsible party
Elham Hedayati (MD, PhD, Karolinska University Hospital) — Principal investigator
First posted
Nov 24, 2021
Start date
Apr 4, 2022
Primary completion
Dec 31, 2022 (estimated)
Completion
Mar 1, 2023 (estimated)
Last update
May 25, 2022

Study contacts

Elham Hedayati, MD PhD
principal investigator · Karolinska University Hospital

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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