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

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.

NCT Number	NCT07044310
Lead Sponsor	Mayo Clinic
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
Enrollment	38 participants
Start Date	2025-07-25
Primary Completion	2027-07-25 (estimated)
Study Completion	2027-07-25 (estimated)
Updated on ClinicalTrials.gov	2026-08-10