Tamoxifen vs Endoxifen for Advanced Breast Cancer
What You Need to Know Before You Apply
What is the purpose of this trial?
This randomized phase II trial studies how well tamoxifen citrate works compared with z-endoxifen hydrochloride in treating patients with breast cancer that has spread to nearby tissue or lymph nodes or other parts of the body and has estrogen receptors but not human epidermal growth factor receptor 2 (HER2) receptors on the surface of its cells. Estrogen can cause the growth of tumor cells. Hormone therapy using tamoxifen citrate or z-endoxifen hydrochloride may fight breast cancer by lowering the amount of estrogen the body makes. It is not yet known whether tamoxifen citrate or z-endoxifen hydrochloride is more effective in treating patients with breast cancer.
Will I have to stop taking my current medications?
The trial does not specify if you must stop taking your current medications, but you cannot be on strong inhibitors of CYP2D6 or other investigational agents. You also need to stop any chemotherapy, immunotherapy, biologic therapy, hormonal therapy, monoclonal antibodies, radiation therapy, or targeted therapy at least 2 weeks before starting the study.
Is Tamoxifen and Endoxifen safe for humans?
Tamoxifen has been used by millions of women for breast cancer and is generally considered safe, with few serious side effects. However, there is a slightly increased risk of endometrial cancer and some concerns about tolerability. Endoxifen, a metabolite of Tamoxifen, has been evaluated in early studies, but more research is needed to fully understand its safety profile.12345
How does the drug Endoxifen differ from other treatments for advanced breast cancer?
Endoxifen is a metabolite of tamoxifen, and its use in advanced breast cancer is being explored as it may offer benefits in cases where tamoxifen resistance has developed. Unlike tamoxifen, which is a selective estrogen receptor modulator (SERM), Endoxifen directly targets the estrogen receptor, potentially providing a more effective option for patients who do not respond to traditional therapies.678910
What data supports the effectiveness of the drug Endoxifen Hydrochloride and Tamoxifen Citrate for advanced breast cancer?
Who Is on the Research Team?
Matthew P Goetz
Principal Investigator
Alliance for Clinical Trials in Oncology
Are You a Good Fit for This Trial?
This trial is for postmenopausal women with advanced or metastatic estrogen receptor-positive, HER2-negative breast cancer. Participants must have been treated previously with an aromatase inhibitor and can't be on strong CYP2D6 inhibitors or have had more than two chemotherapy treatments in the metastatic setting. They should not have brain metastases, uncontrolled illnesses, certain blood disorders, or a recent history of significant blood clots.Inclusion Criteria
Exclusion Criteria
Timeline for a Trial Participant
Screening
Participants are screened for eligibility to participate in the trial
Treatment
Participants receive either z-endoxifen hydrochloride or tamoxifen citrate orally on days 1-21, with courses repeating every 21 days in the absence of disease progression or unacceptable toxicity.
Follow-up
Participants are monitored for safety and effectiveness after treatment completion, with follow-up occurring yearly for up to 5 years.
What Are the Treatments Tested in This Trial?
Interventions
- Endoxifen Hydrochloride
- Tamoxifen Citrate
Find a Clinic Near You
Who Is Running the Clinical Trial?
National Cancer Institute (NCI)
Lead Sponsor