MedTrace Logo

Dose-determining and Dose-confirmatory Study to Investigate the Optimal Dose of Tamoxifen in Breast Cancer Patients According to Genotype Status of TCF20 rs932376

NCT04961632 · Status: ACTIVE_NOT_RECRUITING · Phase: PHASE1 · Type: INTERVENTIONAL · Enrollment: 75

Last updated 2024-02-01

No results posted yet for this study

Summary

The investigators hypothesize that the TCF20 rs932376 locus controls endoxifen levels in estrogen receptor (ER)-positive breast cancer patients on tamoxifen therapy and that the requirement of tamoxifen dose to achieve therapeutic levels of endoxifen varies according to the genotype status of the patient's at the TCF20 rs932376 locus.

Patients will receive escalating doses of tamoxifen according to their TCF20 rs932376 genotype status. Patients on 20mg tamoxifen daily for 8 weeks or longer will provide blood samples for analysis of tamoxifen and its metabolites. Patients assess with \>30nM endoxifen concentrations will continue with 20mg tamoxifen dose. Patients who have endoxifen concentrations \<30nM will receive dose increments of 10mg every 8 weeks until they achieve endoxifen threshold of \>30nM or reach maximum dose level of 40mg/day.

Conditions

Interventions

DRUG

Tamoxifen

Patients taking 20mg tamoxifen will receive dose increments of 10mg every 8 weeks until endoxin threshold of \>30nM or the maximum dose of 40mg/day is reached. The escalated dose will be taken for 1 year before reverting back to 20mg.

DRUG

Tamoxifen

Patients will take tamoxifen at the ascribed genotype-determined dose as determined in the dose-determination phase.

Sponsors & Collaborators

  • National Medical Research Council (NMRC), Singapore

    collaborator OTHER_GOV

  • National Cancer Centre, Singapore

    lead OTHER

Principal Investigators

  • Elaine Lim · National Cancer Centre, Singapore

Study Design

Allocation
NON_RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Model
SEQUENTIAL

Eligibility

Min Age
21 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2020-12-23
Primary Completion
2025-11-30
Completion
2025-11-30

Countries

  • Singapore

Study Locations

More Related Trials

Entities

Diseases

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT04961632 on ClinicalTrials.gov