Effect of Oral (Z)-Endoxifen in Premenopausal Women With Measurable Breast Density

  • End date
    Dec 31, 2024
  • participants needed
  • sponsor
    Atossa Genetics, Inc.
Updated on 26 March 2022
Accepts healthy volunteers


This is a randomized, double-blinded, placebo-controlled dose-response efficacy study of oral (Z)-endoxifen in premenopausal women with measurable breast density. There will be 5 in-clinic visits (Screening, Day 1, Months 1, 3 and 6) and 3 self-report visits (Months 2, 4 and 5). Standard of care mammograms will be used for the screening mammogram as well as the 24-month follow up visit.

Condition Breast Density
Treatment Placebo, Z-Endoxifen
Clinical Study IdentifierNCT05068388
SponsorAtossa Genetics, Inc.
Last Modified on26 March 2022


Yes No Not Sure

Inclusion Criteria

Premenopausal women (defined as having at least one menstruation during the prior 12 months; women with an intrauterine device are considered premenopausal if <52 years)
Women of childbearing potential using a highly effective method of birth control throughout the study period and willing to comply with monthly pregnancy testing
Screening mammogram performed within 3 month of study inclusion
Mammographic density assessed as BI-RADS® score B, C, or D
Must have given written informed consent before any study-related activities are carried out and must be able to understand the full nature and purpose of the trial, including possible risks and adverse effects

Exclusion Criteria

Mammographic BI-RADS® malignancy code ≥3 at baseline mammography
Any previous diagnosis of breast cancer, including carcinoma in situ, or any other cancer (non-melanoma skin cancer and in situ cancer of the cervix are not exclusion criteria)
A history of breast surgery, e.g., reduction or enlargement, which might affect mammographic density measurements
Current medical conditions
APC (activated protein C) resistance, an inherited coagulation disorder
Systolic pressure higher than 160 mm Hg or diastolic higher than 100 mm Hg
Uncontrolled diabetes (defined as HbA1c >50 mmol/mol)
Abnormal lab values deemed clinically significant by Investigator
BMI > 30
Women who have an increased risk of venous thrombosis due to immobilization, e.g., using wheelchair
Agents that have the potential to decrease endoxifen levels through increased metabolic clearance
Certain anti-epileptic therapies (carbamazepine, fenytoin, fenobarbital, lamotrigine)
Certain antibiotics (rifamycins)
St John's wort (in Swedish: johannesört)
Certain HIV medications (efavirenz, ritonavir)
Lactating, pregnant, or plan to become pregnant in the next year
History of thromboembolic disease such as embolus, deep vein thrombosis, stroke, TIA (transient ischemic attack) or myocardial infarction
Allergy to endoxifen or any of its components
Previous treatment with an anti-oestrogen, including experimental drug studies (e.g., Karma CREME, Karisma-1 or Karisma-2)
Prescribed and regular use of anticoagulants (defined as substances included in group B01A in the ATC-system)
Participation in another investigational clinical trial in the last 6 months
Not willing or able to understand the study information and/or informed consent
Clear my responses

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Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

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If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

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Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

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