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Selective Estrogen Receptor Modulator

Tamoxifen vs Endoxifen for Advanced Breast Cancer

Phase 2

Waitlist Available

Led By Matthew P Goetz

Research Sponsored by National Cancer Institute (NCI)

Eligibility Criteria Checklist

Specific guidelines that determine who can or cannot participate in a clinical trial

Must have

Patient must have been previously treated with an aromatase inhibitor (letrozole, anastrozole, or exemestane) either in the adjuvant or metastatic setting, and have primary or secondary endocrine resistant disease

Patients with a history of measurable disease as defined by RECIST criteria or bone only disease are eligible

Must not have

Not postmenopausal women

Receiving medications or substances that are strong inhibitors of cytochrome P450 family 2, subfamily D, polypeptide 6 (CYP2D6)

Timeline

Screening 3 weeks

Treatment Varies

Follow Up up to 5 years

Awards & highlights

Approved for 10 Other Conditions

No Placebo-Only Group

All Individual Drugs Already Approved

Summary

This trial compares tamoxifen citrate to z-endoxifen hydrochloride in treating patients with breast cancer that has spread and has estrogen receptors but not human epidermal growth factor receptor 2 (HER2) receptors.

Who is the study for?

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.

What is being tested?

The study compares tamoxifen citrate and z-endoxifen hydrochloride to see which one is better at treating patients whose breast cancer has spread and relies on estrogen to grow. The trial includes lab biomarker analysis and pharmacological studies to assess how well these hormone therapies work.

What are the potential side effects?

Potential side effects may include hot flashes, mood swings, changes in menstrual flow for premenopausal women (not applicable here as participants are postmenopausal), fatigue, vision problems like cataracts or retinopathy, risk of blood clots such as deep vein thrombosis/pulmonary embolism (especially important given the exclusion criteria), and possible liver function changes.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below

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I was treated with an aromatase inhibitor for my cancer and it did not respond well.

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My cancer can be measured by scans or is only in my bones.

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I am not taking strong inhibitors of CYP2D6.

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My breast cancer is confirmed to be estrogen receptor positive and HER2 negative.

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My cancer is not HER2 positive according to specific guidelines.

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I have fully recovered from the side effects of my previous treatments.

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I agree to a biopsy to confirm my breast cancer is ER+ and HER2-.

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I have gone through menopause.

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I can take pills by mouth.

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My cancer is estrogen receptor positive.

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I have had 2 or fewer chemotherapy treatments for my cancer after it spread.

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I haven't had any cancer other than non-melanoma skin cancer in the last 3 years.

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I can take care of myself and am up and about more than half of my waking hours.

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My cancer can be measured by scans or is only in my bones.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:

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I am not postmenopausal.

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I am not taking strong inhibitors of CYP2D6.

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I have not had any cancer other than non-melanoma skin cancer in the last 3 years.

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I cannot swallow pills.

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I have had more than two chemotherapy treatments for cancer that has spread.

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My cancer affects my spinal cord or heart.

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I need considerable assistance and am unable to carry out any work activities.

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My cancer has spread to my internal organs or lymph system.

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I do not have any unmanaged ongoing illnesses.

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I have cancer that has spread to my brain.

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I am currently not on treatments like chemotherapy, immunotherapy, or radiation.

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I have serious eye problems like advanced cataracts or retinopathy.

Timeline

Screening ~ 3 weeks3 visits

Treatment ~ Varies

Follow Up ~ up to 5 years

Screening ~ 3 weeks

Treatment ~ Varies

Follow Up ~up to 5 years

This trial's timeline: 3 weeks for screening, Varies for treatment, and up to 5 years for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.

Primary study objectives

Progression Free Survival (PFS)

Secondary study objectives

Incidence of Adverse Events, Per Common Terminology Criteria for Adverse Events (CTCAE) Version 4.0

Upper arm

Tumor Response Rate by Study Arm, Defined as the Number of Patients With a Complete or Partial Response

Other study objectives

Change in Biochemical Markers of Bone Turnover

DNA

Nuclear Receptor Coactivator 3 (SRC3) Immunohistochemistry Expression Levels

+4 more

Awards & Highlights

Approved for 10 Other Conditions

This treatment demonstrated efficacy for 10 other conditions.

No Placebo-Only Group

All patients enrolled in this study will receive some form of active treatment.

All Individual Drugs Already Approved

Therapies where all constituent drugs have already been approved are likely to have better-understood side effect profiles.

Trial Design

2Treatment groups

Experimental Treatment

Group I: Arm II (tamoxifen citrate)Experimental Treatment3 Interventions

Patients receive tamoxifen citrate PO QD on days 1-21. Courses repeat every 21 days in the absence of disease progression or unacceptable toxicity. Patients with disease progression and bone metastases may cross over to Arm I and receive z-endoxifen hydrochloride starting no later than 28 days after documentation of disease progression.

Group II: Arm I (z-endoxifen hydrochloride)Experimental Treatment3 Interventions

Patients receive z-endoxifen hydrochloride PO on days 1-21. Courses repeat every 21 days in the absence of disease progression or unacceptable toxicity.

Treatment

First Studied

Drug Approval Stage

How many patients have taken this drug

Tamoxifen

FDA approved

0 / 26Eligibility criteria met