A Study to Investigate Safety and Tolerability of NDX-3315 and NDX-3324 in Healthy Participants and Patients with Eosinophilic Esophagitis

Eligibility Criteria

• * Healthy Participants:
• * EoE Participants:
• * Documented diagnosis of EoE (based on prior endoscopy with biopsies showing eosinophils ≥15 / HPF); AND
• * History (by patient report) of recurrent dysphagia and/or other related EoE symptoms (with intake of solids off anti-inflammatory therapy) prior to screening; dysphagia is defined as trouble swallowing solid food, or having solid food stuck, by patient report.
• * Medical Conditions:
• * Participant with presence of any other disease of the GI tract, including cancer, autoimmune esophageal disease, GERD which is symptomatic or uncontrolled, Barrett's esophagus, eosinophilic gastritis, enteritis, colitis, or proctitis; inflammatory bowel disease; or celiac disease. Known motility disorder of esophagus; achalasia or suspicion thereof.
• * Sleep apnea, if considered by the investigator a concern for the endoscopic procedure.
• * History of recurrent aspiration pneumonia.
• * History of bleeding disorders, liver cirrhosis or esophageal varices.
• * A current malignancy or previous history of cancer in remission for less than 5 years prior to Screening (participants will not be excluded if they had localized carcinoma of the skin that was resected for cure).
• * Participant with a Body Mass Index \>40 m2/kg or inability to undergo a CT (or SPECT scan) due to weight limitations.
• * Participant is pregnant or nursing.
• * Prior/Concomitant Therapy:
• * Participant who is on anticoagulation therapy that, in the investigator or Medical Monitor's opinion, cannot safely come off medication.
• * Use of chronic aspirin (with the exception of low-dose aspirin as long as the dose remains stable and not increased while on study), nonsteroidal agents, or anti-coagulants within 2 weeks prior to screening.
• * Use of systemic corticosteroids within 3 months or swallowed topical corticosteroids within 6 weeks prior to Screening visit.
• * Participant is being treated with systemic immunosuppression, carafate (sucralfate), or investigational agent of any kind within less than 3 months or 5 half-lives, whichever is longer, prior to Screening visit (this also includes investigational formulations of marketed products).
• * Diagnostic Assessments:
• * Evidence of clinically significant abnormality in the hematological and biochemical assessments at Screening Visit, specifically: International Normalized Ratio (INR) \>1.4; platelet count \<80,000/μL and creatinine level \>2 mg/dL.
• * ECG: QTcF ≥450 msec for males and QTcF ≥470 msec for females at the time of screening.
• * Other