Testing Effectiveness of Losartan in Patients With EoE With or Without a CTD

Inclusion Criteria

• Confirmed diagnosis of eosinophilic esophagitis.
• Have been on a high dose proton pump inhibitor for at least 8 weeks prior to a diagnostic endoscopy of eosinophilic esophagitis without histologic resolution.
• Agree to maintain the same diet throughout the duration of the study.
• If participant is female: meet one of the following criteria:
• Is of non-childbearing potential (pre-menarchal or surgically sterile with documentation)
• Is of childbearing potential with a negative urine pregnancy test at screening.

Exclusion Criteria

• Past or planned cardiac surgeries.
• Had an aortic root Z-score greater than 3 on a previous echocardiogram.
• Have intolerance to the study agent such as angioedema, IgE-mediated allergy.
• Have renal dysfunction with creatinine in excess of the upper normal limit for age.
• Have another disorder that causes esophageal eosinophilia (e.g., hypereosinophilic syndrome, Churg Strauss vasculitis, eosinophilic granuloma, or a parasitic infection).
• Diagnosed with hepatic insufficiency.
• History of abnormal gastric or duodenal biopsy or documented gastrointestinal (GI) disorders (e.g., Celiac Disease, Crohn's disease or helicobacter pylori infection.), not including chronic gastritis, chronic duodenitis, mucosal eosinophilia or other eosinophilic gastrointestinal disorders.
• Used anti-immunoglobulin E [IgE] mAb, anti-tumor necrosis factor [TNF] mAb, anti-IL-5 agents, or anti-IL-13 within the last six months.
• Used methotrexate, cyclosporine, interferon-α, or other systemic immunosuppressive or immunomodulating agents within the last three months.
• Have a history of a stricture during an endoscopy procedure that prevents passage of the endoscope.
• Taking or plan to take an angiotensin II receptor blocker (ARB) therapy, angiotensin-converting enzyme inhibitor (ACEI), beta blocker therapy (BB), or calcium channel blocker at the screening visit or at any time during the study, or have you been taking any of these medications for the last three months.
• If the participant is female: pregnant or nursing.
• Taking any investigative drug or device study within the last 30 days.
• Had participated in any investigative biologics study within the last three months prior to the study entry.
• Taking or plan to take hydrochlorothiazide, warfarin, cimetidine, phenobarbital, rifampin, or fluconazole.
• If the participant is female: using a medically accepted effective method of birth control.
• Will be able to complete all study procedures including endoscopy.
• Taking or plan to take potassium supplements or salt substitutes containing potassium.