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

Inclusion Criteria: * Healthy Participants: • Participants who are healthy as determined by medical evaluation including medical history, physical examination, laboratory tests, and electrocardiogram (ECG) assessment. * 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. Exclusion Criteria: * 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 i…