Breast CancerPhase 1NCT04961632
Dose-determining and Dose-confirmatory Study to Investigate the Optimal Dose of Tamoxifen in Breast Cancer Patients According to Genotype Status of TCF20 rs932376
A Phase 1 study testing Tamoxifen in people with Breast Cancer, run by National Cancer Centre, Singapore at 1 site in Singapore.
Trial 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… Read more about this study
- Who is it for?
- Ages 21 years and older
- Conditions the study is for
- Breast Cancer
- What is being tested?
- Tamoxifen
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 75 participants
- Where
- 1 siteSingapore
- Study dates
- 23 Dec 2020to Nov 2025
- Phase
- Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Histologically or cytologically confirmed stage I to IV breast cancer
- Age greater than 21 years
- Estrogen- or progesterone-receptor positive tumours
- Patients receiving tamoxifen 20mg daily as monotherapy
- Patients currently taking tamoxifen in either adjuvant or metastatic setting for greater than or equal to 8 weeks (for Dose determination and confirmation phases)
- Patients who will commence on tamoxifen therapy in either adjuvant or metastatic setting (for Dose confirmation phase only)
- Written and informed consent from participating patients
Who cannot join
- Patients with expected survival less than 6 months
- Patients who are human epidermal growth factor receptor 2 (HER2)-postitive
- Inability to provide informed consent
- Patients receiving CYP2D6 inhibitors or inducers within the past four weeks from the time of study enrollment. However, patients started in CYP2D6 inhibitors or inducers after commencing on tamoxifen therapy will not be excluded from the study.
- Pregnancy
- Patients with prior malignancies other than those who have received curative treatment for basal cell carcinoma of the skin or carcinoma in situ of the uterine cervix
- Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/ social situations that would limit compliance with study requirements.
- Patients who have documented prior allergic reaction to tamoxifen
Trial locations and contacts
1 site in 1 country.
About this study
Official title: An Open-label, Single-institution, Dose-determining (Part 1) and Dose-confirmatory (Part II) Study to Investigate the Optimal Dose of Tamoxifen in Breast Cancer Patients Harboring Different TCF20 rs932376 Variant Alleles
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
- Breast Cancer
- Being tested
- Tamoxifen
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
TamoxifenDrug
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.
TamoxifenDrug
Patients will take tamoxifen at the ascribed genotype-determined dose as determined in the dose-determination phase.
| Study group | Role | What they receive |
|---|---|---|
| Dose-determination | Experimental | Not described Receives: Drug: Tamoxifen |
| Dose-confirmation | Experimental | Not described Receives: Drug: Tamoxifen |
What is being measured
The primary outcome is the main question the study is designed to answer.
Endoxifen blood concentration
To determine the optimal dose of tamoxifen required to achieve therapeutic endoxifen levels for each TCF20 rs932376 genotype group in the dose-determination phase
Measured: 8 weeks after each tamoxifen dose level at 20mg, 30mg and 40mg
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Jul 2021
- Study start23 Dec 2020
- Primary completionNov 2025 (estimated)
- Study completionNov 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Breast CancerStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 75 participants (actual)
Sponsor and investigators
- Lead sponsor
- National Cancer Centre, Singapore
- Sponsor type
- University, hospital or other
- Collaborators
- National Medical Research Council (NMRC), Singapore
- Responsible party
- Sponsor
- Investigators
- Elaine Lim, Principal investigator, National Cancer Centre, Singapore
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04961632
- Sponsor's protocol ID
- TCF20-BRE-01
- Status last verified
- Jan 2024
- First submitted
- 5 Jul 2021
- Last updated
- 1 Feb 2024
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 1 Feb 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open-label, Single-institution, Dose-determining (Part 1) and Dose-confirmatory (Part II) Study to Investigate the Optimal Dose of Tamoxifen in Breast Cancer Patients Harboring Different TCF20 rs932376 Variant Alleles
- ClinicalTrials.gov ID
- NCT04961632
- Acronym / sponsor ID
- TCF20-BRE-01
- Conditions
- Breast Cancer
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 75 participants (actual)
- Lead sponsor
- National Cancer Centre, SingaporeUniversity, hospital or other
- Collaborators
- National Medical Research Council (NMRC), Singapore
- Study start
- 23 Dec 2020 (actual)
- Primary completion
- Nov 2025 (estimated)
- Study completion
- Nov 2025 (estimated)
- First posted
- 14 Jul 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Dose-determination | Experimental | Drug: Tamoxifen |
| Dose-confirmation | Experimental | Drug: Tamoxifen |
Who may qualify
- Ages
- 21 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Histologically or cytologically confirmed stage I to IV breast cancer
- Age greater than 21 years
- Estrogen- or progesterone-receptor positive tumours
- Patients receiving tamoxifen 20mg daily as monotherapy
- Patients currently taking tamoxifen in either adjuvant or metastatic setting for greater than or equal to 8 weeks (for Dose determination and confirmation phases)
Key exclusion criteria (8 listed)
- Patients with expected survival less than 6 months
- Patients who are human epidermal growth factor receptor 2 (HER2)-postitive
- Inability to provide informed consent
- Patients receiving CYP2D6 inhibitors or inducers within the past four weeks from the time of study enrollment. However, patients started in CYP2D6 inhibitors or inducers after commencing on tamoxifen therapy will not be excluded from the study.
- Pregnancy
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| TamoxifenPatients 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 | Dose-determination |
| TamoxifenPatients will take tamoxifen at the ascribed genotype-determined dose as determined in the dose-determination phase. | Drug | Dose-confirmation |
Primary outcome
Endoxifen blood concentration
Time frame: 8 weeks after each tamoxifen dose level at 20mg, 30mg and 40mg
To determine the optimal dose of tamoxifen required to achieve therapeutic endoxifen levels for each TCF20 rs932376 genotype group in the dose-determination phase
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Feb 2024.
Related trials for Breast Cancer
Enrolling by invitationObservational study
Natural History Study of Early Life Exposures in Agriculture (ELEA)
Prostate Cancer, Leukemia
RecruitingPhase 3
A Study Evaluating the Efficacy and Safety of Inavolisib Plus CDK4/6 Inhibitor and Letrozole vs Placebo + CDK4/6i and Letrozole in Participants With Endocrine-Sensitive PIK3CA-Mutated, Hormone Receptor-Positive, HER2-Negative Advanced Breast Cancer
Breast Cancer
Not yet recruitingPhase 1
Safety and Biodistribution of [68Ga]Ga DOTA-5G in Subjects With Metastatic Breast Cancer (BC)
Metastatic Breast Cancer
Active, not recruiting
Peer Navigator Education in Improving Survivorship Care in African American Breast Cancer Survivors
Breast Cancer
RecruitingObservational study
Improved Facial Skin Quality and Quality of Life After VYC-12L Treatment in Breast Cancer Survivors
Quality of Life, Breast Neoplasms
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Elaine Lim principal investigator
National Cancer Centre, Singapore
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Tamoxifen in people with Breast Cancer, run by National Cancer Centre, Singapore at 1 site in Singapore.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 1 Feb 2024. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Singapore. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Endoxifen blood concentration (time frame: 8 weeks after each tamoxifen dose level at 20mg, 30mg and 40mg). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Feb 2024.