(Z)-Endoxifen for the Treatment of Premenopausal Women With ER+/HER2- Breast Cancer (EVANGELINE)

A Phase 2 Trial of (Z)-Endoxifen + Goserelin as Neoadjuvant Treatment for Premenopausal Women With ER+, HER2-, Breast Cancer

This open-label research study is studying (Z)-endoxifen as a possible treatment for pre-menopausal women with ER+/HER2- breast cancer. (Z)-endoxifen belongs to a group of drugs called selective estrogen receptor modulators or "SERM", which help block estrogen from attaching to cancer cells. This study has two parts: a pharmacokinetic part and a treatment part.

The PK part (how the body processes the drug) will enroll about 18 participants. All participants will take (Z)-endoxifen capsules daily. Twelve participants will be randomly assigned (50/50 chance) to take (Z)-endoxifen alone or (Z)-endoxifen with a monthly injection of goserelin a drug that temporarily stops the ovaries from making estrogen. This part will help determine the best dose of (Z)-endoxifen by measuring the drug levels in the blood and how long the body takes to remove it.

The Treatment Cohort has been simplified to a single study arm (Z)-endoxifen + goserelin. Up to 20 participants will be enrolled that have a baseline Ki-67 ≤ 10% and 45 participants will be enrolled that have a baseline Ki-67>10%.

A key goal of the study is to see if (Z)-endoxifen can slow down or stop tumor growth as measured by a reduction in Ki-67 levels. Tumor tissue samples will be taken by breast biopsy after about 4 weeks of treatment to check levels of this biomarker. If the tumor shows signs of response, participants can continue treatment for up to 24 weeks or until they have surgery.

Study participation is up to 6 months (24 weeks of treatment) followed by surgery and a one-month follow up visit.

Study Overview

• Status: Recruiting
• Conditions: Breast Neoplasms; Invasive Breast Cancer; HER2-negative Breast Cancer; Estrogen-receptor-positive Breast Cancer
• Intervention / Treatment: Drug: goserelin; Drug: (Z)-endoxifen

• Study Type: Interventional
• Enrollment (Estimated): 87
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Hayley Erickson; Phone Number: 206-486-1872; Email: hayley.erickson@atossainc.com

Study Locations

• United States
  • Arizona
    • Phoenix, Arizona, United States, 85054
      • Recruiting
      • Mayo Clinic Arizona
      • Principal Investigator: Lida Mina, MD
    • Tucson, Arizona, United States, 85719
      • Recruiting
      • University of Arizona
      • Principal Investigator: Sima Ehsani, MD
  • California
    • Los Angeles, California, United States, 90027
      • Recruiting
      • California Research Institute
      • Principal Investigator: Ghassan Al-Jazayrly, MD
  • Florida
    • Jacksonville, Florida, United States, 32224
      • Recruiting
      • Mayo Clinic Florida
      • Principal Investigator: Pooja Advani, MD
  • Illinois
    • Chicago, Illinois, United States, 60611
      • Recruiting
      • Northwestern University
      • Principal Investigator: Seema Khan, MD
  • Kentucky
    • Edgewood, Kentucky, United States, 41017
      • Recruiting
      • St. Elizabeth Healthcare
      • Principal Investigator: Daniel Flora, MD
  • Michigan
    • Detroit, Michigan, United States, 48202
      • Recruiting
      • Henry Ford Cancer Institute
      • Principal Investigator: Vrushali Dabak, MD
  • Minnesota
    • Rochester, Minnesota, United States, 55905
      • Recruiting
      • Mayo Clinic Rochester
      • Principal Investigator: Matthew Goetz, MD
  • Missouri
    • St Louis, Missouri, United States, 63110
      • Recruiting
      • Washington University School of Medicine
      • Principal Investigator: Nusayba Bagegni, MD
  • South Dakota
    • Sioux Falls, South Dakota, United States, 57105
      • Recruiting
      • Avera Cancer Institute
      • Principal Investigator: Jason Jones, MD
  • Tennessee
    • Nashville, Tennessee, United States, 37204
      • Recruiting
      • Vanderbilt Ingram Cancer Center
      • Principal Investigator: Vandana Abramson, MD
  • Texas
    • Houston, Texas, United States, 77054
      • Recruiting
      • Baylor University
      • Principal Investigator: Ahmed Elkhanany, MD
    • Webster, Texas, United States, 77598
      • Withdrawn
      • Tranquility Research
  • Virginia
    • Midlothian, Virginia, United States, 23114
      • Recruiting
      • Bon Secours Cancer Institute
      • Principal Investigator: William Irvin, MD
  • Washington
    • Seattle, Washington, United States, 98109
      • Recruiting
      • Fred Hutchinson Cancer Center
      • Principal Investigator: Hannah Linden, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Female sex assigned at birth. Female to male transgender individuals who have not had any hormonal therapy may be considered for the trial after review and approval from the medical monitor and study sponsor.
2. Age 18 years or older
3. Not lactating, pregnant, or planning to become pregnant in the next year and agrees to take adequate steps to prevent becoming pregnant beginning at informed consent, during treatment and for 9 months after last dose and agree to not breast feed during treatment and for 3 months after last dose.
4. Must agree to use at least one non-hormonal highly effective method of contraception for the entire duration of study participation beginning at informed consent. Highly effective methods of birth control are defined as those, alone or in combination, that resulted in a low failure rate of <1% per year when used consistently and correctly such as intrauterine devices (IUDs, non-hormonal such as copper IUD), bilateral tubal occlusion, sexual abstinence or vasectomized partner

5. Premenopausal defined as any female who:

   1. is menstruating or
   2. is not menstruating (last menstrual period > 3 months prior to registration) but has a plasma estradiol in the premenopausal range as assessed locally
6. Pathologic confirmation of strongly estrogen receptor positive (ER+) (defined as estrogen receptor [ER] ≥ 67% or Allred Score 6-8) by local institution protocol
7. Eastern Cooperative Oncology Group ECOG Performance Status (ECOG PS) of 0 to 2
8. Nottingham (Elston-Ellis) Grade 1 or 2
9. HER2- breast cancer (histologically confirmed) using American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines
10. Clinical T2 or T3 invasive breast cancer (per American Joint Committee on Cancer [AJCC] 8th edition clinical staging)
11. Clinical N0 or N1 invasive breast cancer (per American Joint Committee on Cancer [AJCC] 8th edition clinical staging)
12. MRI ≤ 35 days of registration
13. 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
14. Willing to provide blood and breast tissue samples for research purposes at specified timepoints for the duration of their participation in the trial.

Exclusion Criteria:

1. Bilateral invasive breast cancer; Inflammatory breast cancer defined as clinically significant erythema of the breast and/or documented dermal lymphatic invasion or bilateral invasive breast cancer (patients with pre-malignant disease or DCIS/LCIS in contralateral breast are eligible)

2. Prior diagnosis or treatment for breast cancer, including carcinoma in situ, or history of any other active malignancy within the past 2 years prior to study entry with the exception of:

   1. Adequately treated in situ carcinoma of the cervix uteri
   2. Adequately treated basal cell carcinoma or localized squamous cell carcinoma of the skin
   3. Any other malignancy with a life expectancy of less than 2 years

3. Any uncontrolled intercurrent illness including, but not limited to:

   1. Ongoing or active infection requiring systemic treatment with strong inhibitors/inducers of CYP450 enzymes (including bacterial infection, fungal infection, or detectable viral infection).
   2. Symptomatic congestive heart failure,
   3. Unstable angina pectoris,
   4. Uncontrolled symptomatic cardiac arrhythmias
   5. Uncontrolled hypertension
   6. Uncontrolled diabetes (Hemoglobin A1c [HbA1c] >7%)
   7. Marked baseline prolongation of QT/QTc interval (e.g., repeated demonstration of a QTc interval > 470 milliseconds [msec]) using Fridericia's QT correction formula seen ≤ 28 days of registration

4. Any of the following co-morbid conditions:

   1. Known cataracts or retinopathy
   2. History of deep vein thrombosis (DVT)/pulmonary embolism (PE)
   3. Known activated protein C (APC) resistance, an inherited coagulation disorder
   4. End stage kidney disease requiring dialysis

5. Evidence of the following laboratory abnormalities ≤ 28 days prior to registration:

   1. Total bilirubin ≥ 1.5 x upper limit of normal (ULN)
   2. Aspartate aminotransferase (AST) or alanine amino transferase (ALT) ≥ 2.5 x ULN
   3. Platelet count (PLT) ≤ 75,000/mm3
   4. Hemoglobin (Hb) ≤ 10 g/dL
6. Hormonal therapies including birth control and hormone replacement therapy, or prior use of androgen-based therapy during the study or within 1 week of registration. If subject has a prior medical history of Depo-Provera®, it is recommended that the last dose of 3-month contraceptive agents are > 2.5 months from registration.
7. Allergy to endoxifen, goserelin, or exemestane or any of their components
8. Participation in another investigational clinical trial ≤ 6 months of registration
9. Known metastatic disease

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: PK Cohort; (Z)-endoxifen capsules orally once daily for 4 weeks. Initial (Z)-endoxifen dose evaluated will be 40 mg with an option to evaluate 20 mg or 80 mg. The PK Cohort participants may extend treatment based on Ki-67% at Week 4. If Ki-67 ≤ 10% at Week 4, participant will be offered option to continue on this treatment for up to 6 cycles/Week 24. Each cycle is 28 days. If Ki-67 > 10% at Week 4, participant will be withdrawn and go on to surgery.	Drug: (Z)-endoxifen; (Z)-endoxifen capsules. Doses of (Z)-endoxifen to be evaluated include 20 mg (two x 10 mg capsules), 40 mg (one 40 mg capsule) and 80 mg (two x 40 mg capsules).; Other Names: endoxifen
Experimental: PK Cohort 80 mg; (Z)-endoxifen 80 mg capsules orally once daily for 4 weeks. The PK Cohort participants may extend treatment based on Ki-67% at Week 4. If Ki-67 ≤ 10% at Week 4, participant will be offered option to continue on this treatment for up to 6 cycles/Week 24. Each cycle is 28 days. If Ki-67 > 10% at Week 4, participant will be withdrawn and go on to surgery.	Drug: (Z)-endoxifen; (Z)-endoxifen capsules. Doses of (Z)-endoxifen to be evaluated include 20 mg (two x 10 mg capsules), 40 mg (one 40 mg capsule) and 80 mg (two x 40 mg capsules).; Other Names: endoxifen
Experimental: PK Cohort 80 mg + OFS; (Z)-endoxifen 80 mg capsules orally once daily for 4 weeks + goserelin 3.6 mg by subcutaneous implant approximately every 28 days. The PK Cohort participants may extend treatment based on Ki-67% at Week 4. If Ki-67 ≤ 10% at Week 4, participant will be offered option to continue on this treatment for up to 6 cycles/Week 24. Each cycle is 28 days. If Ki-67 > 10% at Week 4, participant will be withdrawn and go on to surgery.	Drug: goserelin; goserelin 3.6 mg subcutaneous implant; Other Names: Zoladex; Drug: (Z)-endoxifen; (Z)-endoxifen capsules. Doses of (Z)-endoxifen to be evaluated include 20 mg (two x 10 mg capsules), 40 mg (one 40 mg capsule) and 80 mg (two x 40 mg capsules).; Other Names: endoxifen
Experimental: Treatment Cohort - Single Treatment Arm; (Z)-endoxifen 40mg capsules orally once daily for 4 weeks + goserelin 3.6 mg by subcutaneous implant approximately every 28 days. (Z)-endoxifen 40mg dose based on results of PK Cohort. If Ki-67 ≤ 10% at Week 4, continue on this treatment for up to 6 cycles/Week 24. Each cycle is 28 days. And then go on to surgery within 3 weeks of Cycle 6 day 26. If Ki-67 > 10% at Week 4, participant will complete early termination assessments.	Drug: goserelin; goserelin 3.6 mg subcutaneous implant; Other Names: Zoladex; Drug: (Z)-endoxifen; (Z)-endoxifen capsules. Doses of (Z)-endoxifen to be evaluated include 20 mg (two x 10 mg capsules), 40 mg (one 40 mg capsule) and 80 mg (two x 40 mg capsules).; Other Names: endoxifen

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
PK Cohort - (Z)-endoxifen steady-state plasma concentrations	(Z)-endoxifen steady-state plasma concentrations (Css) of evaluable subjects who completed at least one cycle of treatment (28 +/- 3 days)	After 4 weeks of treatment
For Analysis of Cohort A (Treatment Cohort): determine whether the week 4 Ki-67≤10% rate is at least 65%	For analysis Cohort A (subjects that have a baseline Ki-67>10%): the primary objective is to determine whether the Week 4 Ki-67 ≤ 10% rate is at least 65% among premenopausal women with primary estrogen receptor positive (ER+), Human Epidermal Growth Factor Receptor 2 negative (HER2-) breast cancer.	After 4 weeks of treatment
For analysis Cohort B (Treatment Cohort): determine the objective tumor response rate at 24 weeks	For analysis Cohort B (subjects have baseline Ki-67≤ 10%): the primary objective is to determine the objective tumor response rate at 24 weeks among premenopausal women with ER+, HER2-, Ki-67 ≤ 10% breast cancer receiving (Z) endoxifen plus goserelin.	After 24 weeks of treatment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
PK Cohort - Area under the plasma (Z)-endoxifen concentration-time curve from time zero to last measurable concentration	Area under the plasma (Z)-endoxifen concentration-time curve from time zero to last measurable concentration (AUC0-24) on Days 1 and 28 of evaluable subjects who completed at least one cycle of treatment (28 +/- 3 days)	Days 1 and 28
PK Cohort - Area under the plasma (E)-endoxifen concentration-time curve from time zero to last measurable concentration	Area under the plasma (E)-endoxifen concentration-time curve from time zero to last measurable concentration (AUC0-24) on Days 1 and 28 of evaluable subjects who completed at least one cycle of treatment (28 +/- 3 days)	Days 1 and 28
PK Cohort - Accumulation and accumulation half-life	Accumulation and accumulation half-life (Day 28 AUC0-24/Day 1 AUC0-24) of evaluable subjects who completed at least one cycle of treatment (28 +/- 3 days)	Days 1 and 28
PK Cohort - (Z)-endoxifen steady-state clearance	(Z)-endoxifen CLss (steady-state clearance) of evaluable subjects who completed at least one cycle of treatment (28 +/- 3 days)	up to 28 days
PK Cohort - (E)-endoxifen steady-state clearance	(E)-endoxifen CLss (steady-state clearance) of evaluable subjects who completed at least one cycle of treatment (28 +/- 3 days)	up to 28 days
PK Cohort - Maximum plasma (Z)-endoxifen concentration	Maximum plasma (Z)-endoxifen concentration (Cmax) of evaluable subjects who completed at least one cycle of treatment (28 +/- 3 days)	up to 28 days
PK Cohort - Maximum plasma (E)-endoxifen concentration	Maximum plasma (E)-endoxifen concentration (Cmax) of evaluable subjects who completed at least one cycle of treatment (28 +/- 3 days)	up to 28 days
PK Cohort - Time to plasma (Z)-endoxifen maximum concentration	Time to plasma (Z)-endoxifen maximum concentration (Tmax) of evaluable subjects who completed at least one cycle of treatment (28 +/- 3 days)	up to 28 days
PK Cohort - Time to plasma (E)-endoxifen maximum concentration	Time to plasma (E)-endoxifen maximum concentration (Tmax) of evaluable subjects who completed at least one cycle of treatment (28 +/- 3 days)	up to 28 days
PK Cohort - plasma (Z)-endoxifen concentration	Trough concentrations of (Z)-endoxifen for subjects in the Treatment Extension	Day 1 up to 12 weeks and up to end of treatment or up to 24 weeks.
PK Cohort - plasma (E)-endoxifen concentration	Trough concentrations of (Z)-endoxifen for subjects in the Treatment Extension	Day 1 up to 12 weeks and up to end of treatment or up to 24 weeks.
Treatment Cohorts - Change in menopause quality of life (MENQOL)	Evaluate changes in menopause symptoms after neoadjuvant treatment	baseline, up to 4 weeks, and up to 24 weeks
Treatment Cohorts - Nodal response rate	Rate of nodal pCR in subjects with biopsy proven nodal disease	At time of surgery or up to 27 weeks
PK Cohort- Endocrine sensitive disease rate based on Ki-67 percent after 4 weeks of treatment	Endocrine sensitive disease rate will be estimated as the percentage of subjects whose 4-week tumor biopsy finds Ki-67 less than or equal to 10 percent among evaluable subjects who began protocol treatment	After 4 weeks of treatment
All Cohorts - Incidence and severity of adverse events per CTCAE by treatment	Incidence and severity of adverse events per CTCAE	Informed consent up to follow up visit or up to 30 weeks
All Cohorts - Incidence of Serious Adverse Events assessed by CTCAE version 5.0	Serious adverse events and adverse events leading to discontinuation of neoadjuvant treatment	Informed consent up to follow up visit or up to 30 weeks
All Cohorts - Incidence of Dose Reductions	The incidence of dose reductions	Informed consent up to end of treatment or up to 24 weeks
All Cohorts - Change in estradiol and estrone	Percent change from baseline in E1 and E2 at 4 weeks, and 24 weeks	Day 1, up to 4 weeks and up to end of treatment or up to 24 weeks.
All Cohorts - Percentage of subjects whose serum thymidine kinase 1 (TK1) is not detectable at 4 weeks and 24 weeks.	Percent of subjects whose serum TK1 is not detectable at 4 weeks and 24 weeks	Day 1, up to 4 weeks and up to end of treatment or up to 24 weeks.
Treatment Cohorts - Assess additional PK parameters of (Z)-endoxifen and (E)-endoxifen	Tissue and plasma (Z)-endoxifen and (E)-endoxifen concentrations at 4 weeks and 24 weeks	Day 1, up to 4 weeks, up to 12 weeks and up to 24 weeks
Treatment Cohorts - Radiographic Response Rate in the breast	Radiographic response rate in the breast at 4, 12, and 24 weeks as assessed by RECIST 1.1 criteria	Baseline Assessment, up to 4 weeks, up to 12 weeks, and up to 24 weeks
Treatment Cohorts - Pathologic Complete Response per American Joint Committee on Cancer staging system at time of surgery	Pathologic Complete Response (pCR) at surgery defined as the absence of residual invasive breast cancer on hematoxylin and eosin evaluation of the resected breast specimen and of all sampled lymph nodes (sentinel ± axillary) removed following completion of neoadjuvant systemic therapy	At time of surgery or up to 27 weeks
Treatment Cohorts - Pre-Operative Endocrine Prognostic Index at time of surgery	Rate of Pre-Operative Endocrine Prognostic Index (PEPI) 0 at time of surgery using residual tumor specimen	At time of surgery or up to 27 weeks
Treatment Cohorts - Residual Cancer Burden at time of surgery	Rate of residual cancer burden class of 0-I at time of surgery	At time of surgery or up to 27 weeks
Treatment Cohorts - Conversion Rate	Evaluate the conversion rate from breast conservation surgery ineligible to breast conservation surgery eligible. Evaluation is based on surgeon's impression of the type of surgery participant is eligible for (candidate for lumpectomy, candidate for modified radical mastectomy, inoperable) at baseline compared to surgeon's impression after completion of neoadjuvant treatment	From baseline to time of surgery or up to 27 weeks
Treatment Cohorts - Actual Conversion Rate	Evaluate the actual rate of breast conservation surgery. Evaluation will be based on the extent of the surgical procedure at the time of surgery (lumpectomy, partial or segmental mastectomy, simple/total mastectomy, skin and/or nipple sparing mastectomy, radical mastectomy or other)	At time of surgery or up to 27 weeks

Collaborators and Investigators

• Sponsor: Atossa Therapeutics, Inc.
• Collaborators: InClin
• Investigators: Principal Investigator: Matthew P Goetz, MD, Mayo Clinic

Study record dates

Study Major Dates

• Study Start (Actual): February 14, 2023
• Primary Completion (Estimated): November 1, 2026
• Study Completion (Estimated): April 1, 2027

Study Registration Dates

• First Submitted: October 26, 2022
• First Submitted That Met QC Criteria: October 31, 2022
• First Posted (Actual): November 7, 2022

Study Record Updates

• Last Update Posted (Estimated): October 30, 2025
• Last Update Submitted That Met QC Criteria: October 29, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Keywords: breast cancer; neoadjuvant; tamoxifen; Stage II; Ki-67; human epidermal growth factor receptor 2 negative; ER+/HER2-; endocrine therapy; (Z)-endoxifen; exemestane; goserelin; estrogen receptor negative; PKCB1
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Skin Diseases; Breast Diseases; Skin and Connective Tissue Diseases; Breast Neoplasms; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Pituitary Hormone-Releasing Hormones; Hypothalamic Hormones; Peptide Hormones; Neuropeptides; Peptides; Amino Acids, Peptides, and Proteins; Oligopeptides; Nerve Tissue Proteins; Proteins; Gonadotropin-Releasing Hormone; Goserelin; 4-hydroxy-N-desmethyltamoxifen
• Other Study ID Numbers: ATOS-Z-201

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No