Clinical trials are carefully designed research studies to determine whether new drugs or treatments work to control or cure a disease, symptom, side effect or improve quality of life.

The sponsor of this clinical trial is Atossa Therapeutics.  Atossa is a biopharmaceutical company headquartered in Seattle, Washington, whose mission is to develop innovative medicines in areas of significant unmet medical needs in oncology with a focus on breast cancer. 

(Z)-endoxifen is an investigational drug, meaning it has not been approved by the FDA. (Z)-endoxifen belongs to a class of drugs called selective estrogen receptor modulators (SERMs).  SERMs are a type of hormonal therapy medicine used to treat estrogen receptor-positive (ER+) breast cancer. 

SERMs block your body’s natural estrogen from binding with cancer cells in the breast. By cutting off the supply of estrogen, SERMs can stop ER+ cancer from growing and spreading in some patients.  In addition, there is evidence that (Z)-endoxifen may have additional anti-cancer properties through other mechanisms.

In premenopausal women, or those who still have periods, adequately treating ER+ breast cancer often includes additional medications that further cut off the supply of estrogen produced by functioning ovaries (also known as ovarian function suppression or OFS). In the EVANGELINE study, we will observe the safety and anti-cancer benefits of (Z)-endoxifen plus OFS.

This is an open-label, , Phase 2 pre-surgical (also called neoadjuvant) study in premenopausal women 18 years of age and older with newly diagnosed early-stage ER+/HER2- breast cancer. Participants will receive endocrine treatment for up to 24 weeks and then have surgery.  The primary goal of the study is to: 

1) Part 1 - (Completed) Find a dose of (Z)-endoxifen that reaches certain levels in the blood that researchers have shown produce enhanced anti-cancer benefits.  This dose will be used in Part 2 of the study.

In Part 1, patients were treated with (Z)-endoxifen, either alone or with Ovarian Function Suppression (OFS), to determine the dosing regimen for Part 2. A total of 22 patients received (Z)-endoxifen, with or without OFS. The comprehensive analysis of the data from Part 1 was used to select the appropriate dosing amount for Part 2.

2) Part 2 – (replaced with Part 3)  See if (Z)-endoxifen is just as effective at decreasing cancer cell growth compared to a standard treatment.

In Part 2 participants were assigned to one of three groups: receive (Z)-endoxifen once daily with goserelin, (Z)-endoxifen alone without goserelin,  or the current standard of care.

3) Part 3- (Enrolling) See if (Z)-endoxifen is an effective alternative to current Aromatase Inhibitor-based regimens and to expand endocrine therapy options for this population of breast cancer patients. This part will enroll about 65 participants who will receive (Z)-endoxifen once daily by mouth + one injection of goserelin every 28 days.  You will be closely monitored for safety (with blood draws, tests, and interviews) and disease progression (by MRIs). Biopsies will be taken from your tumor at the start of treatment and after 4 weeks of treatment. Biopsies will help your doctor decide if your cancer is sensitive to treatment by measuring Ki-67, a commonly studied marker of breast cancer cell growth. 

If after 4 weeks of treatment, your biopsy shows the treatment is not working for you, you  will discontinue study treatment. Once treatment is complete, approximately 24 weeks, you will go on to have surgery.  If you respond to treatment, your surgery may be less invasive.

Additional information can be obtained from the national clinical study register, Clinicaltrials.gov. (click here NCT05607004).

There are no placebos in this study. Everyone will receive treatment for their breast cancer.

No, the focus of this study is premenopausal women. If you are not having periods and you are unsure if you are menopausal, your doctor will take a blood test to confirm.

Your trial doctor will make the decision if you are eligible for the study.  

It depends on how well you respond to treatment.  It could be as short as 3 months or as long as 9 months.

About 65

Your primary care physician or oncologist may be able to refer you to one of the clinical trial sites.