5-strain Probiotic Formulation in HR-positive Breast Cancer Receiving Aromatase Inhibitor to Prevent Bone Loss

NCT07044310 | Recruiting Phase 2 DMC FDA Drug

• 3 other identifiers: MC240302NCI-2025-0426724-007055
• Study Type: interventional
• Target: 38
• Locations: 1 country
• Sites: 1

Brief Summary

This phase II trial tests how well a probiotic, WBF-038, works in preventing bone loss in patients with early-stage hormone receptor-positive breast cancer who are starting treatment with aromatase inhibitors. Aromatase inhibitors are a drug that blocks the activity of an enzyme called aromatase, which the body uses to make estrogen in the ovaries and other tissues. Blocking aromatase lowers the amount of estrogen made by the body, which may stop the growth of cancer cells that need estrogen to grow. Aromatase inhibitors are used to treat some types of breast cancer or to keep it from coming back. Aromatase inhibitors can affect bone health, weight, blood sugar, and waist size. WBF-038 is a combination of both prebiotics and probiotics, designed to improve metabolic health. Giving WBF-038 may improve bone turnover, bone health, blood sugar, weight, and waist circumference in patients with early-stage hormone receptor-positive breast cancer starting on adjuvant endocrine therapy with an aromatase inhibitor.

Conditions

Anatomic Stage 0 Breast Cancer AJCC v8; Anatomic Stage I Breast Cancer AJCC v8; Anatomic Stage II Breast Cancer AJCC v8; Anatomic Stage III Breast Cancer AJCC v8; Hormone Receptor-Positive Breast Carcinoma

Outcome Measures

Primary Outcomes (1)

• Change in C-terminal telopeptide of type 1 collagen (CTx)

  Assessed by standard lab tests at baseline (at study enrollment/eligibility assessment before any therapy) followed by 6 study visits. Participants receive aromatase Inhibitor (AI) therapy followed by a one-year course of probiotic WBF-038.

  Baseline; 90 days after start of AI therapy (before beginning WBF-038); 14 days after start of WBF-038; 90 days after start of WBF-038; 180 days after start of WBF-038; 365 days after start of WBF-038; 90 days after stopping WBF-038

Secondary Outcomes (3)

• Change in lumbar spine mineral density

  Baseline; 365 days after start of WBF-038

• Change in hip bone mineral density

  Baseline; 365 days after start of WBF-038

• Incidence of adverse events

  Baseline; 90 days after start of AI therapy (before beginning WBF-038); 90 days after start of WBF-038; 365 days after starting WBF-038; 90 days after stopping WBF-038;

Study Arms (1)

Supportive care (WBF-038)

EXPERIMENTAL

Patients receive WBF-038 PO QD for 365 days in the absence of disease progression or unacceptable toxicity. Patients also undergo blood sample collection and BMD test at screening and on study.

Procedure: Biospecimen Collection; Procedure: Bone Mineral Density Test; Other: Questionnaire Administration; Drug: WBF-038

Interventions

Biospecimen Collection PROCEDURE

Undergo blood sample collection

Also known as: Biological Sample Collection, Biospecimen Collected, Specimen Collection

Supportive care (WBF-038)

Bone Mineral Density Test PROCEDURE

Undergo BMD

Also known as: BMD, bone density, Bone Density Test, bone mass, Bone Mineral Density

Supportive care (WBF-038)

Questionnaire Administration OTHER

Ancillary studies

Supportive care (WBF-038)

WBF-038 DRUG

Given WBF-038 PO

Also known as: Akkermansia muciniphila/Anaerobutyricum hallii/Bifidobacterium infantis/Clostridium beijerinckii/Clostridium butyricum/Inulin WBF-038, Pendulum WBF-038 (SY), Probiotic/Prebiotic Formulation WBF-038 (SY), Synbiotic Formulation WBF-038 (SY), WBF 038 (CN), WBF-038 (CN), WBF038 (CN)

Supportive care (WBF-038)

Eligibility Criteria

• Age: 18 Years+
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Female age ≥ 18 years
• Eastern Cooperative Oncology Group (ECOG) performance status 0, 1, or 2
• Histologically confirmed anatomical stage 0-III hormone receptor-positive breast cancer
• Will be starting on an aromatase inhibitor (letrozole, anastrozole, or exemestane) ± ovarian function suppression (OFS) per treating physician's discretion
• Absolute neutrophil count (ANC) ≥ 1000/mm\^3 (prior to registration)
• Platelet count ≥ 75,000/mm\^3 (prior to registration)
• Hemoglobin ≥ 9.0 g/dL (prior to registration)
• Creatinine ≤ 2 x upper limit of normal (ULN) (prior to registration)
• Serum glutamic-oxaloacetic transaminase (SGOT) (aspartate aminotransferase \[AST\]) ≤ 2 x ULN (prior to registration)
• Albumin ≥ 3 g/dL (prior to registration)
• Willing and able to provide research stool and blood samples
• Negative serum pregnancy test done ≤ 7 days prior to registration, for women of childbearing potential only (\< 60 years old with intact uterus)
• Capable of providing valid informed consent
• Willing to return to enrolling institution for all study visits (blood draws, etc)

You may not qualify if:

• Requires prolonged systemic antibiotic therapy for other conditions and recent systemic antibiotic ≤ 14 days prior to registration
• Fecal microbiota transplant (FMT) ≤ 6 months prior to registration
• FMT with an associated serious adverse event related to the FMT product or procedure
• Co-morbid systemic illnesses or other severe concurrent diseases which, in the judgment of the investigator, would make the patient inappropriate for entry into this study or interfere significantly with the proper assessment of safety and toxicity of over-the-counter probiotics
• Immunocompromised patients including patients known to be HIV positive or those on chronic steroids \> 20 mg prednisone a day or prednisone-equivalent. Note: Must be off systemic steroids ≥ 90 days prior to registration. However, topical steroids, inhalants, or steroid eye drops are permitted
• History of inflammatory bowel disease (IBD), e.g., ulcerative colitis, Crohn's disease, or microscopic colitis
• History of chronic diarrhea
• History of celiac disease
• Currently has a colostomy
• Intraabdominal surgery related to gastrointestinal tract ≤ 60 days prior to registration
• Evidence of active, severe colitis
• History of short gut syndrome or motility disorders
• Requires the daily use of medications to manage bowel hypermotility, such as imodium or lomotil
• Active autoimmune disease that has required systemic treatment in the ≤ 30 days (i.e., with the use of disease-modifying agents, corticosteroids, or immunosuppressive products) prior to registration. Note: Replacement therapy (e.g., thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency) is not considered a form of systemic treatment. Patients with vitiligo, Graves' disease, or psoriasis not requiring systemic treatment ≤ 30 days prior to registration are not excluded
• History of osteoporosis or hyperparathyroidism

Sponsors & Collaborators

• Mayo Clinic: lead

Study Sites (1)

Mayo Clinic in Florida

Jacksonville, Florida, 32224-9980, United States

RECRUITING

Related Links

• Mayo Clinic Clinical Trials

MeSH Terms

Conditions

Breast Carcinoma In Situ

Interventions

Specimen Handling; Bone Density; Probiotics

Condition Hierarchy (Ancestors)

Carcinoma in Situ; Carcinoma; Neoplasms, Glandular and Epithelial; Neoplasms by Histologic Type; Neoplasms; Breast Neoplasms; Neoplasms by Site; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases

Intervention Hierarchy (Ancestors)

Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Investigative Techniques; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Dietary Supplements; Food; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages

Study Officials

• Saranya Chumsri, MD

  Mayo Clinic

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Clinical Trials Referral Office

CONTACT

855-776-0015; mayocliniccancerstudies@mayo.edu

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: SUPPORTIVE CARE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 26, 2025
• First Posted: June 29, 2025
• Study Start: July 25, 2025
• Primary Completion (Estimated): July 25, 2027
• Study Completion (Estimated): July 25, 2027
• Last Updated: July 29, 2025

Record last verified: 2025-07

Locations

US (1)