Gastrointestinal STRING Test With Oral Immunotherapy

Stanford University (Other)
Overall Status
Enrolling by invitation ID

Study Details

Study Description

Brief Summary

This STRING study will examine markers of esophageal inflammation using a minimally-invasive testing device, the esophageal string test (EST). The primary objective is to determine the effect of omalizumab (Xolair) and dupilumab (Dupixent) on markers of eosinophilic inflammation in the esophagus of subjects treated with omalizumab-facilitated mOIT(mult-allergen oral immunotherapy) and/or mOIT with concurrent dupilumab.

Condition or Disease Intervention/Treatment Phase
  • Device: Entero-tracker

Detailed Description

This is a companion study to a phase 2 randomized, controlled, double-blind clinical trial using biologics to improve multi-allergen oral immunotherapy (mOIT) outcomes. The parent study (COMBINE NCT03679676) consists of a screening period, 8 weeks of omalizumab or placebo injections, and 24 weeks of OIT with dupilumab or placebo injections followed by an off-treatment period.

This STRING companion study will examine markers of esophageal inflammation during the COMBINE study using a minimally-invasive testing device, the esophageal string test (EST). If participants of COMBINE consent to this companion study, they will undergo an esophageal string test at the following time points in COMBINE:

  • During screening, prior to week 0, which will be baseline for the STRING esophageal test

  • Week 8, After the 8 weeks of treatment with omalizumab/placebo

  • If dose-related gastrointestinal (GI) side effects occur during the week 10-32 treatment period (OIT and dupilumab/placebo)

  • At Week 32, after 24 weeks of treatment with OIT and dupilumab or placebo

Study Design

Study Type:
Anticipated Enrollment :
50 participants
Observational Model:
Time Perspective:
Official Title:
Monitoring Gastrointestinal Responses In Food Oral Immunotherapy Using the Esophageal STRING Test
Actual Study Start Date :
May 17, 2021
Anticipated Primary Completion Date :
Dec 31, 2022
Anticipated Study Completion Date :
Dec 31, 2022

Arms and Interventions

Arm Intervention/Treatment
String Test

Participants in the COMBINE study will have an EST performed at pre- specified timepoints (screening, week 8, and week 32) and as needed depending on GI symptoms.

Device: Entero-tracker
Esophageal STRING test (Entero-tracker)

Outcome Measures

Primary Outcome Measures

  1. Comparison of the proportion of subjects with esophageal eosinophilia (EE) [32 weeks]

    (defined as an EST score ≥ 2.9) in subjects receiving omalizumab-facilitated mOIT and/or mOIT with concurrent

Secondary Outcome Measures

  1. Comparison of EST scores [8 weeks]

    Comparison of EST scores (composite measure of eosinophilic inflammation) before and after treatment with omalizumab

Eligibility Criteria


Ages Eligible for Study:
5 Years to 55 Years
Sexes Eligible for Study:
Accepts Healthy Volunteers:

Inclusion Criteria: • Participants, aged 5-55 years enrolled in the parent COMBINE trial

  • Able to swallow the EST.

Exclusion Criteria: • Allergy to, or inability to ingest, gelatin


Contacts and Locations


Site City State Country Postal Code
1 Sean N Parker Center for Allergy and Asthma Research at Stanford University Mountain View California United States 94040

Sponsors and Collaborators

  • Stanford University


  • Principal Investigator: Sharon Chinthrajah, MD, Stanford University

Study Documents (Full-Text)

None provided.

More Information


None provided.
Responsible Party:
R. Sharon Chinthrajah, Medical Director, Clinical Research Uni, Stanford University Identifier:
Other Study ID Numbers:
  • 58997
First Posted:
Jun 29, 2021
Last Update Posted:
Sep 5, 2021
Last Verified:
Sep 1, 2021
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD:
Studies a U.S. FDA-regulated Drug Product:
Studies a U.S. FDA-regulated Device Product:
Additional relevant MeSH terms:

Study Results

No Results Posted as of Sep 5, 2021