Clinical trial · Interventional
Tamoxifen Dose Adjustment on Indonesian Female ER+ Breast Cancer Patients Based on CYP2D6 Genotype and Endoxifen Levels
Tamoxifen Dose Adjustment on ER+ Breast Cancer Patients Based on Genomic and Metabolite Concentrations Analysis
NCT04312347CI-TRIAL-00053092completedN/AClinicalTrials.gov clinicaltrialsProvenance
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 8, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260908-000001
Summary
Brief summary (as posted)
The objectives of this study is to perform CYP2D6 genotyping and metabolite concentrations analysis on ER+ breast cancer patients who are taking tamoxifen and give dose recommendations based on the CYP2D6 genotypes and endoxifen levels.
Conditions
Conditions (1)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| ER+ Breast Cancer | Breast Neoplasm | ONTOLOGY_EXACT | 0.90 |
Interventions
Interventions (1)
| Intervention | Type | Mapped drug | Match |
|---|---|---|---|
| Tamoxifen dose adjustment | Drug | — | UNRESOLVED |
Design
Arms and outcomes
Arms (1)
- type
- EXPERIMENTAL
- label
- Personalized dosing of tamoxifen
- description
- Increase tamoxifen dose into 40 mg/day for patients with low endoxifen level and poor/intermediate metabolizer CYP2D6 phenotype.
- interventionNames
- Drug: Tamoxifen dose adjustment
Primary outcomes (3)
- measure
- Effects of genotype and phenotype of CYP2D6 on plasma and serum concentration of tamoxifen and its metabolites
- timeFrame
- 8 weeks after initial tamoxifen intake
- measure
- Effects of dose recommendation of tamoxifen based on CYP2D6 genotyping results on endoxifen levels
- timeFrame
- 8 weeks after dose recommendation
- measure
- Frequencies of CYP2D6 alleles in female Indonesian population
Eligibility
Eligibility (as posted)
- Sex
- Female
- Minimum age
- 18 Years
Show eligibility criteria text
Inclusion Criteria: * Diagnosed with ER+ breast cancer * Have taken tamoxifen daily for at least 2 months Exclusion Criteria: * Have not taken tamoxifen daily for at least 2 months
References
Publications (2)
- BACKGROUNDMadlensky 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. PMID 21430657
- BACKGROUNDFox P, Balleine RL, Lee C, Gao B, Balakrishnar B, Menzies AM, Yeap SH, Ali SS, Gebski V, Provan P, Coulter S, Liddle C, Hui R, Kefford R, Lynch J, Wong M, Wilcken N, Gurney H. Dose Escalation of Tamoxifen in Patients with Low Endoxifen Level: Evidence for Therapeutic Drug Monitoring-The TADE Study. Clin Cancer Res. 2016 Jul 1;22(13):3164-71. doi: 10.1158/1078-0432.CCR-15-1470. Epub 2016 Feb 4. PMID 26847054