Pharmacokinetics of IFX and TNF Concentrations in Serum, Stool, and Colonic Mucosa in Acute Severe Ulcerative Colitis (PROTOS)

May 29, 2026 updated by: Alimentiv Inc.

Pharmacokinetics of Infliximab and Tumor Necrosis Factor Concentrations in Serum, Stool, and Colonic Mucosa in Acute Severe Ulcerative Colitis

This is an open-label, prospective, observational study with the primary objective to characterize the pharmacokinetics of infliximab in patients with Acute Severe Ulcerative Colitis.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

In Acute Severe Ulcerative Colitis (ASUC), drug exposure may be affected by intestinal protein loss leading to hypoalbuminemia and rapid clearance of infliximab (IFX). Importantly, 2 studies have associated the loss of IFX in stool with poor outcomes. Multiple observational studies have identified that patients with faster IFX clearance have worse clinical outcomes and higher rates of antidrug antibody formation. To better understand optimal dosing of IFX in ASUC, the pharmacokinetics of IFX in association with outcomes must be better defined in this setting.

Study Type

Observational

Enrollment (Actual)

18

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Ontario
      • Toronto, Ontario, Canada, M5G 1X5
        • Mount Sinai Hospital
  • United States
    • California
      • San Diego, California, United States, 92037
        • UCSD
    • New York
      • New York, New York, United States, 10065
        • Cornell University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients diagnosed with acute severe ulcerative colitis, who are biologic-naive or biologic-experienced without a known history of anti-infliximab antibodies and will be receiving infliximab infusion therapy.

Description

Inclusion Criteria:

  • Present to hospital with ASUC based on Truelove and Witts criteria,33 defined as the presence of more than 6 bloody stools per day along with any 1 of the following: tachycardia > 90 beats per minute, fever > 37.8 °C, hemoglobin < 10.5 g/dL, and erythrocyte sedimentation rate (ESR) > 30 mm/h (or CRP > 30 mg/L [high-sensitivity CRP > 300 mg/L]) is a suitable surrogate if ESR is not available1).
  • Have a partial MCS > 7.
  • Have a Mayo Clinic ES ≥ 2 with disease extending 15 cm or more beyond the anal verge.
  • Require rescue inpatient IFX infusion as part of routine care. Note, the IFX treatment regimen is not defined by this protocol and any dosage regimen is acceptable for the purposes of this study, such as standard or accelerated induction regimens.
  • Be able to speak English and participate fully in all aspects of this clinical trial.
  • Provide written informed consent.

Exclusion Criteria:

  • A known history of being positive for anti-IFX antibodies.
  • Have a serious active infection, active malignancy, or any other known condition contraindicated with infliximab therapy, according to current prescribing information.
  • Serious underlying disease other than ASUC, or other physical or psychosocial condition that, in the opinion of the investigator, may interfere with the subject's ability to participate fully in the study.
  • Prior enrollment in the current study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Single Group Study
Patients with Acute Severe Ulcerative Colitis who are either a) biologic-naïve or b) biologic-experienced without a known history of anti-infliximab antibodies requiring infliximab infusion therapy as a part of standard of care.
Drug: Infliximab
Patients will receive infliximab at the discretion of their physician as part of standard of care.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Inter-compartmental Difference in Infliximab Concentration
Time Frame: 22 weeks
Infliximab population pharmacokinetics
22 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Proteome
Time Frame: 22 weeks
Change in Proteomics before and after therapy
22 weeks
Change in Transcriptome
Time Frame: 22 weeks
Change in Transcriptomics before and after therapy
22 weeks
Change in Robarts Histopathologic Index
Time Frame: 22 weeks
Change in Robarts Histopathologic Index before and after therapy The RHI consists of 4 histological items (extent of chronic inflammatory cell infiltration, neutrophils in the lamina propria, neutrophils in the epithelium, and erosions and ulceration) scored from 0 to 3 and multiplied by a weighting factor. The total RHI score is calculated by summing the weighted scores of the histological items, with total scores ranging from 0 (no disease activity) to 33 (severe disease activity).
22 weeks
Change in Mayo Clinic Endoscopic Score
Time Frame: 22 weeks

Change in Mayo Clinic Endoscopic Score before and after therapy The Mayo Clinic score (MCS) scores 4 variables (stool frequency, rectal bleeding, a physician's global assessment and endoscopic findings with flexible sigmoidoscopy). The endoscopic component of the MCS assesses disease activity on a 4-point scale (0-3 points), with higher scores representing more severe disease activity. Mucosal healing is often defined as an endoscopy score of 0 or 1.

Normal or inactive disease = 0 Mild disease (erythema, decreased vascular pattern, mild friability) = 1 Moderate disease (marked erythema, absent vascular pattern, friability, erosions) = 2 Severe (spontaneous bleeding, ulceration) = 3
22 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Alimentiv Inc.

Investigators

  • Study Director: Niels Vande Casteele, UCSD

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 21, 2018

Primary Completion (Actual)

December 22, 2023

Study Completion (Estimated)

December 1, 2027

Study Registration Dates

First Submitted

December 4, 2018

First Submitted That Met QC Criteria

December 4, 2018

First Posted (Actual)

December 5, 2018

Study Record Updates

Last Update Posted (Actual)

June 2, 2026

Last Update Submitted That Met QC Criteria

May 29, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • RP1713

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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