Losartan in Prevention of Radiation-Induced Heart Failure

The Role of Losartan in the Prevention of Early Structural Changes Associated With Radiation-Induced Heart Failure

This study is being done to see if losartan affects the chances of developing radiation-induced heart failure in patients who are receiving radiation therapy as part of standard of care treatment for breast cancer. The interventions involved in this study are: Losartan Radiation Therapy (standard of care)

This is a pilot study examining whether losartan prevents radiation therapy-induced myocardial fibrosis (thickening of the heart tissue), which can cause heart failure, in breast cancer patients receiving radiation therapy. Losartan is an U.S. Food and Drug Administration (FDA) approved drug used to treat hypertension (high blood pressure) and heart failure. The U.S. Food and Drug Administration (FDA) has not approved losartan for use in the treatment of breast cancer. The FDA has approved radiation therapy as a treatment option for breast cancer. The research study procedures include: screening for eligibility and study treatment including evaluations and follow up visits. It is expected participants will be on the study for 1 year. It is expected that about 10 people will take part in this research study.

Participants will receive radiation therapy 5x weekly over 1-6 weeks. Participants will receive Losartan 1x daily during radiation therapy and for up to 6 months afterward then be followed for 1 year

The secondary objective of this study is to compare pre- and post-Radiation Therapy changes in serum TGF-β levels

Inclusion Criteria: ->18 years of age Non-metastatic Breast Cancer patients who are scheduled to receive conventional left breast/chest wall RT inclusive of treatment to the internal mammary lymph nodes (IMNs) Prior chemotherapy is permitted Patients must have Left-sided Breast Cancer Ability to understand and the willingness to sign a written informed consent document No contraindication to MRI Exclusion Criteria: Person who is pregnant or breastfeeding. Patient unable to swallow oral medication. Patients receiving any other investigational agent will not be excluded from study eligibility, unless the patient is already enrolled in an interventional study evaluating cardiac toxicity Patients already receiving ACE/ARBs. Patients with a history of allergic reactions to Losartan biosimilars.

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