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

NCT05757856 | Completed Phase 2 FDA Drug

• 1 other identifier: NDX-3315-1001
• Study Type: interventional
• Target: 34
• Locations: 1 country
• Sites: 3

Brief Summary

An open-label phase 2 study to assess the safety and exploratory diagnostic performance of the oral radiopharmaceutical agent NDX-3315 and NDX-3324 in healthy participants and patients with eosinophilic esophagitis (EoE).

Conditions

Eosinophilic Esophagitis

Keywords

Eosinophilic Esophagitis; EoE; Diagnostic

Outcome Measures

Primary Outcomes (4)

• The proportion of all participants with AEs following administration of NDX-3315 and NDX-3324

  An adverse event (AE) is any untoward medical occurrence in a study participant administered a pharmaceutical product and that does not necessarily have causal relationship with this treatment.

  From start of study drug administration up to End of Study (EOS) ( Up to 3 Weeks)

• Peak eosinophil counts per high-power field (HPF)

  A blinded pathologist will perform peak eosinophil counts per high-power field (HPF) on biopsy specimens of the esophagus.

  Up to 10 days after last dose

• Absolute quantification of SPECT imaging

  SPECT images will be analyzed for radioactive per region of interest(ROI) of the esophagus.

  Up to 45 minutes after dose

• Determine Concordance of Outcomes

  Determine concordance rate between 1. eMBP1 immunostaining score on biopsy specimens (esophagus) and 2. NDX-3315 and NDX-3324 absolute quantification of SPECT imaging of esophagus

  Up to 10 Days After Last Dose

Secondary Outcomes (6)

• Partial Thromboplastin Time (PTT) as marker of pharmacodynamics (PD)

  Baseline, 2 hours post-dose (Up to 1 Week)

• Radioactivity of blood collected from participants exposed to NDX-3315 and NDX-3324.

  2.5 hours post-dose (Up to 1 Week)

• Visual ratings of SPECT images

  Up to 45 minutes after dose

• Deposition of eMBP1

  Up to 10 days after last dose

• EoE Endoscopic Reference Score (EREFS)

  Up to 10 days after last dose

Study Arms (2)

Participants Receiving NDX-3315

EXPERIMENTAL

Participants receive NDX-3315 (delivered via oral syringe at \~ 1.5 mL per minute) using Regimen 5 (5 sips administered over approximately 5 minutes) or Regimen 10 (10 sips administered over approximately 10 minutes), followed by SPECT/CT imaging. Both healthy participants and participants with EoE are included.

Drug: NDX-3315; Diagnostic Test: SPECT/CT Imaging

Participants Receiving NDX-3324

EXPERIMENTAL

Participants receive NDX-3324 (delivered via oral syringe at \~ 1.5 mL per minute) using Regimen 10 (10 sips administered over approximately 10 minutes) in a sitting reclined position, followed by SPECT/CT imaging. Both healthy participants and participants with EoE are included.

Drug: NDX-3324; Diagnostic Test: SPECT/CT Imaging

Interventions

SPECT/CT Imaging DIAGNOSTIC_TEST

Participants undergo SPECT/CT imaging following administration of NDX-3315 or NDX-3324.

Participants Receiving NDX-3315; Participants Receiving NDX-3324

NDX-3315 DRUG

Oral solution

Participants Receiving NDX-3315

NDX-3324 DRUG

Oral solution

Participants Receiving NDX-3324

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• NexEos Diagnostics, Inc.: lead

Study Sites (3)

Northwestern Univerisity

Chicago, Illinois, 60611, United States

Location

University of Pennsylvania

Philadelphia, Pennsylvania, 19104, United States

Location

University of Utah

Salt Lake City, Utah, 84132, United States

Location

MeSH Terms

Conditions

Eosinophilic Esophagitis; Disease

Condition Hierarchy (Ancestors)

Esophagitis; Esophageal Diseases; Gastrointestinal Diseases; Digestive System Diseases; Gastroenteritis; Eosinophilia; Leukocyte Disorders; Hematologic Diseases; Hemic and Lymphatic Diseases; Hypersensitivity, Immediate; Hypersensitivity; Immune System Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NON RANDOMIZED
• Masking: NONE
• Masking Details: This is an open-label study. However, the pathologist and immunostaining analyst that receive study participant biopsies for analysis, as well as the radiologist that scores the scans, are blinded to EoE diagnosis and other test results.
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: Participants are enrolled into one of two intervention groups. In Arm 1, participants receive NDX-3315 administered orally using Regimen 5 or Regimen 10, followed by SPECT/CT imaging. In Arm 2, participants receive NDX-3324 administered orally using Regimen 10, followed by SPECT/CT imaging. Both healthy participants and participants with EoE are included in both arms.

Study Record Dates

• First Submitted: February 10, 2023
• First Posted: March 7, 2023
• Study Start: January 20, 2023
• Primary Completion: May 22, 2025
• Study Completion: May 22, 2025
• Last Updated: May 14, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

US (3)