Recruiting
Phase 2

ET

Sponsor:

Jose Pablo Leone

Code:

NCT05501704

Conditions

Male Breast Cancer

Hormone Receptor-positive Breast Cancer

Hormone Receptor Negative Breast Carcinoma

Eligibility Criteria

Sex: Male

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Tamoxifen

Anastrozole

Degarelix

Abemaciclib

Study Details

Brief summary:

This research study is looking to see how well male breast cancer responds to preoperative treatment with endocrine therapy and which endocrine therapy regimen is the most effective treatment for male breast cancer.

The drugs used in this study are:

  • Tamoxifen
  • Anastrozole
  • Degarelix
  • Abemaciclib

Conditions

Male Breast Cancer

Hormone Receptor-positive Breast Cancer

Hormone Receptor Negative Breast Carcinoma

Study ID

NCT05501704

Start date

Oct 11, 2023

Status verified date

Aug, 2026

Completion date

Apr 1, 2036

Anticipated

Primary completion date

Apr 1, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Male

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Men aged 18 years or older, with diagnosis of invasive breast cancer who have not undergone surgical resection of the primary tumor and axillary nodes.
  • Stage I, II, or III per American Joint Committee on Cancer (AJCC) staging 8th edition (112).
  • Breast cancer must be hormone receptor-positive and HER2-negative according to definition below assessed by local pathology.

  • Hormone receptor-positive is defined as: positivity for at least one of the hormone receptors (estrogen receptor \[ER\] or progesterone receptor \[PR\]) by IHC. ER and PR assays are considered positive if there are > 1% positive tumor nuclei in the samples.
  • HER2-negative is defined per the current American Society of Clinical Oncology/College of American Pathologists Clinical Practice Guideline (113).
  • Patients with multifocal or multicentric disease are eligible if the treating investigator has determined the patient should be treated as ER-positive and HER2-negative.
  • Bilateral breast cancers are allowed if the treating investigator has determined the patient should be treated as ER-positive and HER2-negative.
  • Patients with a history of ipsilateral or contralateral DCIS or LCIS are eligible.
  • ECOG performance status ≤ 2.
  • Required laboratory values demonstrating adequate organ function:

  • ANC ≥ 1000/mm3
  • Hemoglobin ≥ 8 g/dl
  • Platelets ≥ 50,000/mm3
  • Serum creatinine ≤ 3.0 x ULN (institutional)
  • Total bilirubin ≤ 2.0 x ULN (institutional).
  • AST and ALT ≤ 5.0 x ULN (institutional)
  • Men with partners of childbearing potential must be willing to use one highly effective form of non-hormonal contraception or two effective forms of non-hormonal contraception by the patient and/or partner and continue its use for the duration of the study treatment and for 6 months after the last dose of study treatment.
  • Non-English-speaking patients are eligible but will be exempt from patient-completed questionnaires.
  • Willing and able to sign informed consent.
  • Willing to undergo breast biopsy after completion of window phase.
  • Patient is able to swallow oral medications.

Exclusion Criteria:

  • Prior endocrine therapy, chemotherapy, radiation therapy, or investigational therapy for the current breast cancer diagnosis.
  • Prior endocrine therapy, systemic therapy, radiation therapy, or investigational therapy for any other malignancy within the past 12 months.
  • Diagnosis of inflammatory breast cancer (T4d).
  • Other concurrent serious diseases that may interfere with planned treatment, including severe cardiac disease, congestive heart failure (CHF) of New York Heart Association (NYHA) Class III or higher, severe pulmonary conditions/illness, uncontrolled infections.
  • The patient has serious and/or uncontrolled preexisting medical condition(s) that, in the judgment of the investigator, would preclude participation in this study (for example, interstitial lung disease, severe dyspnea at rest or requiring oxygen therapy, severe renal impairment \[e.g. estimated creatinine clearance <30ml/min\], history of major surgical resection involving the stomach or small bowel, or preexisting Crohn's disease or ulcerative colitis or a preexisting chronic condition resulting in baseline Grade 2 or higher diarrhea).
  • The patient has active systemic bacterial infection (requiring intravenous \[IV\] antibiotics at time of initiating study treatment), fungal infection, or detectable viral infection (such as known human immunodeficiency virus positivity or with known active hepatitis B or C \[for example, hepatitis B surface antigen positive\]. Screening is not required for enrollment.
  • The patient has a personal history of any of the following conditions: syncope of cardiovascular etiology, ventricular arrhythmia of pathological origin (including, but not limited to, ventricular tachycardia and ventricular fibrillation), or sudden cardiac arrest.

Study Design

Enrollment

60 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Window Phase Arm A: Tamoxifen

Participants will be randomly assigned to receive Tamoxifen 1x daily for 3 weeks (21days).

experimental: Window Phase Arm B: Anastrozole

Participants will be randomly assigned to receive Anastrozole 1x daily for 3 weeks (21days).

experimental: Window Phase Arm C: Anastrozole + Degarelix

Participants will be randomly assigned to receive Anastrozole 1x daily for 3 weeks (21days) and Degarelix on day 1 only.

experimental: Neoadjuvant Phase Arm D: Tamoxifen

Participants will be randomly assigned to receive Tamoxifen 1x daily for 4 cycles (4 months); each study cycle is 28 days.

experimental: Neoadjuvant Phase Arm E: Tamoxifen + Abemaciclib

Participants will be randomly assigned to receive Tamoxifen 1x daily and Abemaciclib 2x daily for 4 cycles (4 months); each study cycle is 28 days.

experimental: Neoadjuvant Phase Arm F: Anastrozole and Degarelix

Participants will be randomly assigned to receive Anastrozole 1x daily and Degarelix on day 1 of each cycle for 4 cycles (4 months); each study cycle is 28 days.

experimental: Neoadjuvant Phase Arm G: Anastrozole + Degarelix + Abemaciclib

Participants will be randomly assigned to receive Anastrozole 1x daily, Degarelix on day 1 of each cycle and Abemaciclib 2x daily for 4 cycles (4 months); each study cycle is 28 days.

Interventions

Tamoxifen

Taken orally

Anastrozole

Taken orally

Degarelix

Subcutaneous (under the skin) injection

Abemaciclib

Taken orally

Primary outcome measure

  • Change in Ki-67 [ Time Frame: At the end of the 3-week window period. ]
  • RCB index [ Time Frame: At time of surgery. ]

Central Contacts and Locations

Central contacts

Jose Pablo Leone, MD

617-789-2903josep_leone@dfci.harvard.edu

Locations

Georgetown University Medical Center

Recruiting

Washington D.C., District of Columbia, United States, 20007

Contacts

Clinical Trials Office Breast Cancer

202-444-2223

Principal Investigator:

Elaine Walsh, MD

Mayo Clinical Hospital Florida

Recruiting

Jacksonville, Florida, United States, 32224

Contacts

Mayo Clinic Cancer Center

904-953-2000Klosowski.angelica@mayo.edu

904-953-7610stark.emily@mayo.edu

Principal Investigator:

Rohit Rao, MD

Dana Farber Cancer Institute

Recruiting

Boston, Massachusetts, United States, 02115

Contacts

Jose Pablo Leone, MD

617-789-2903

Principal Investigator:

Jose Pablo Leone, MD

Mayo Clinic

Recruiting

Rochester, Minnesota, United States, 55905

Contacts

Cancer Trials Referral Office

855-776-0015

Principal Investigator:

Kathryn Ruddy, MD

UNC Lineberger Comprehensive Cancer Center

Recruiting

Chapel Hill, North Carolina, United States, 27599

Contacts

Yara Abdou, MD

yara_abdou@med.unc.edu

Principal Investigator:

Yara Abdou, MD

University of Pennsylvania, Abramson Cancer Center

Recruiting

Philadelphia, Pennsylvania, United States, 19104

Contacts

Igor Makhlin, MD

igor.makhlin@pennmedicine.upenn.edu

Principal Investigator:

Igor Makhlin, MD

University of Pittsburgh Cancer Institute

Recruiting

Pittsburgh, Pennsylvania, United States, 15232

Contacts

Rometa Kerney

(412) 641-5430pollardrr@upmc.edu

Principal Investigator:

Priscilla McAuliffe, MD

Vanderbilt Cancer Center

Recruiting

Nashville, Tennessee, United States, 37232

Contacts

Kathy G Taylor

6153222064Kathy.l.taylor@vumc.org

Jessica Sharpe

615.875.0060jessica.m.sharpe@vumc.org

Principal Investigator:

Jessica Sharpe, MD

M. D. Anderson Cancer Center at University of Texas

Recruiting

Houston, Texas, United States, 77030-4009

Contacts

Clinical Trials Office - M. D. Anderson Cancer Center at the U

713-792-3245

Principal Investigator:

Jasmine Sukumar, M.D

More Information

Sponsor

Jose Pablo Leone

Last update posted

Aug 24, 2026

Last verified

Aug, 2026

Keywords

  • Male Breast Cancer
  • Hormone Receptor-positive Breast Cancer
  • Hormone Receptor Negative Breast Cancer

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-08. This information was provided to ClinicalTrials.gov by Jose Pablo Leone on 2026-08-24.