A Phase 2a Safety and Efficacy Open-Label Study of Tulisokibart (MK-7240/PRA023) in Participants With Moderately to Severely Active Crohn's Disease (MK-7240-006) (APOLLO-CD)

March 31, 2026 updated by: Prometheus Biosciences, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA)

A Phase 2a, Multi-Center, Open-Label Study to Evaluate the Safety, Efficacy, and Pharmacokinetics of PRA023 in Subjects With Moderately to Severely Active Crohn's Disease

The purpose of this study is to assess the safety and efficacy of tulisokibart (MK-7240) in participants with moderately to severely active Crohn's Disease.

After the completion of the 12-week Induction Period, eligible participants have the option to enter an Open-label Extension (OLE) Period for up to 170 weeks.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

55

Phase

  • Phase 2

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

  • Australia
    • New South Wales
      • Bankstown, New South Wales, Australia, 2146
        • Prometheus Biosciences Selected Site
    • Queensland
      • Woolloongabba, Queensland, Australia, 4102
        • Prometheus Biosciences Selected Site
    • South Australia
      • Adelaide, South Australia, Australia, 5000
        • Prometheus Biosciences Selected Site
  • Belgium
      • Leuven, Belgium, 3000
        • Prometheus Biosciences Selected Site
      • Liège, Belgium, 4000
        • Prometheus Biosciences Selected Site
  • Canada
    • Ontario
      • London, Ontario, Canada, N6A 5W9
        • Prometheus Biosciences Selected Site
  • Czechia
      • Brno, Czechia
        • Prometheus Biosciences Selected Site
      • Slaný, Czechia, 274 01
        • Prometheus Biosciences Selected Site
  • France
      • Clichy, France, 92110
        • Prometheus Biosciences Selected Site
      • Nice, France, 06202
        • Prometheus Biosciences Selected Site
      • Saint-Priest-en-Jarez, France, 42270
        • Prometheus Biosciences Selected Site
      • Vandœuvre-lès-Nancy, France, 54511
        • Prometheus Biosciences Selected Site
  • Georgia
      • Tbilisi, Georgia
        • Prometheus Biosciences Selected Site
  • Poland
      • Krakow, Poland, 31-501
        • Prometheus Biosciences Selected Center
      • Rzeszów, Poland, 35-326
        • Prometheus Biosciences Selected Site
      • Sopot, Poland, 81-756
        • Prometheus Biosciences Selected Site
      • Torun, Poland, 87-100
        • Prometheus Biosciences Selected Site
      • Warsaw, Poland, 00-635
        • Prometheus Biosciences Selected Center
      • Warsaw, Poland, 03-580
        • Prometheus Biosciences Selected Site
      • Warsaw, Poland, 52-416
        • Prometheus Biosciences Selected Center
      • Wroclaw, Poland, 52-416
        • Prometheus Biosciences Selected Site
  • United States
    • California
      • Los Angeles, California, United States, 90045
        • Prometheus Biosciences Selected Site
      • Los Angeles, California, United States, 90048
        • Prometheus Biosciences Selected Site
    • Kansas
      • Liberty, Kansas, United States, 64098
        • Prometheus Biosciences Selected Site
    • Michigan
      • Chesterfield, Michigan, United States, 48047
        • Prometheus Biosciences Selected Site
      • Ypsilanti, Michigan, United States, 48197
        • Prometheus Biosciences Selected Site
    • Missouri
      • St Louis, Missouri, United States, 63141
        • Prometheus Biosciences Selected Site
    • New Hampshire
      • Lebanon, New Hampshire, United States, 03756
        • Prometheus Biosciences Selected Site
    • New York
      • New York, New York, United States, 10065
        • Prometheus Biosciences Selected Site
    • Texas
      • Garland, Texas, United States, 75044
        • Prometheus Biosciences Selected Site
      • Lubbock, Texas, United States, 79410
        • Prometheus Biosciences Selected Site
      • Lubbock, Texas, United States, 79424
        • Prometheus Biosciences Selected Site
      • San Antonio, Texas, United States, 78229
        • Prometheus Biosciences Selected Site
      • Southlake, Texas, United States, 78229
        • Prometheus Biosciences Selected Site
      • Tyler, Texas, United States, 75702
        • Prometheus Biosciences Selected Site
    • Washington
      • Bellevue, Washington, United States, 98004
        • Prometheus Biosciences Selected Site
      • Tacoma, Washington, United States, 98405
        • Prometheus Biosciences Selected Site

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

Description

Inclusion Criteria:

  • Confirmed diagnosis of Crohn's disease (CD)
  • Moderately to severely active CD as defined by Crohn's disease activity index (CDAI) score and centrally read endoscopy
  • Must have corticosteroid dependence or have had no response, insufficient response, loss of response and/or intolerance to at least one of the following therapies: corticosteroid, immunosuppressants, or an approved anti-tumor necrosis factor (TNF), anti-integrin, or anti-interleukin (IL)12/23
  • Able to provide written informed consent and understand and comply with the requirements of the study

Exclusion Criteria:

  • Women of child bearing potential (WOCBP) and men with female partner of childbearing potential who are unwilling to use two highly effective methods of contraception to avoid pregnancy for the entire study period and up to 12 weeks after the last dose of study drug
  • Diagnosis of ulcerative colitis (UC) or indeterminate colitis
  • CD isolated to the stomach, duodenum, jejunum, or perianal region, without colonic and/or illeal involvement
  • Suspected or diagnosed intra-abdominal or perianal abscess at screening
  • Current stoma or need for colostomy or ileostomy
  • Previous small bowel resection with a combined resected length of >100 cm or previous colonic resection of > 2 segments
  • Surgical bowel resection within 3 months before screening
  • Past or current evidence of definite low-grade or high-grade colonic dysplasia not completely removed
  • Participants in the opinion of the investigator are at an unacceptable risk for participation in the study
  • Participants who meet the protocol criteria for important laboratory exclusion criteria

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

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Induction Tulisokibart
During the 12-week Induction Period, participants receive tulisokibart administered by intravenous (IV) infusion at 1000 mg on Day 1 of Week 0, and 500 mg on Day 1 of Weeks 2, 6, and 10.
Biological: Tulisokibart
Tulisokibart administered by IV infusion as directed by the protocol
Other Names:
  • PRA023
  • MK-7240
Diagnostic test: Companion Diagnostic (CDx)
PRA023 CDx Genotyping Assay
Experimental: OLE Tulisokibart 100 mg
After completing the 12-week Induction Period, eligible participants have the option to enter the OLE Period for up to 170 weeks. Participants are randomized into the OLE Period to receive 100 mg tulisokibart by IV infusion every 4 weeks (q4w).
Biological: Tulisokibart
Tulisokibart administered by IV infusion as directed by the protocol
Other Names:
  • PRA023
  • MK-7240
Experimental: OLE Tulisokibart 250 mg
After completing the 12-week Induction Period, eligible participants have the option to enter the OLE Period for up to 170 weeks. Participants are randomized into the OLE Period to receive 250 mg tulisokibart by IV infusion q4w.
Biological: Tulisokibart
Tulisokibart administered by IV infusion as directed by the protocol
Other Names:
  • PRA023
  • MK-7240

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Adverse Events
Time Frame: Week 12
Number of participants who experienced treatment-emergent adverse events (AEs)
Week 12
Serious Adverse Events
Time Frame: Week 12
Number of participants who experienced serious adverse events (SAEs)
Week 12
Adverse Events Leading to Discontinuation
Time Frame: Week 12
Number of participants who experienced AEs leading to discontinuation
Week 12
Endoscopic Improvement
Time Frame: Week 12
Number of participants achieving induction of endoscopic improvement (decrease in simple endoscopy score for Crohn's disease [SES-CD] ≥ 50% from Baseline)
Week 12

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Clinical Remission
Time Frame: Week 12
Number of participants achieving clinical remission, as defined by Crohn's disease activity index [CDAI] score < 150
Week 12
Endoscopic and Clinical Improvement
Time Frame: Week 12
Number of participants who achieved a decrease in SES-CD ≥ 50% AND reduction in CDAI ≥ 100 points from Baseline or CDAI<150
Week 12
Number of Participants Achieving a Composite Response
Time Frame: Week 12
Composite response is defined as a decrease by at least 50% in hsCRP or fecal calprotectin from baseline and a reduction of either CDAI ≥ 100 points from Baseline or CDAI<150 in subjects with at least one elevated biomarker at baseline.
Week 12
Normalization of C-reactive Protein
Time Frame: Week 12
Number of participants with normalization of hsCRP (as defined by hsCRP < 5 mg/L), among subjects with elevated concentrations at Baseline, at Week 12
Week 12
Normalization of Fecal Calprotectin
Time Frame: Week 12
Number of participants with normalization of fecal calprotectin (fecal calprotectin < 250 ug/g), among subjects with elevated concentrations at Baseline, at Week 12
Week 12
Clinical Response
Time Frame: Week 12
Clinical response is defined as either a reduction of either CDAI ≥ 100 points from Baseline or CDAI<150.
Week 12
Two Component Patient-reported Outcome (PRO-2) Remission
Time Frame: Week 12
Number of subjects with PRO-2 remission (defined as average daily abdominal pain score ≤ 1 point and average daily stool frequency ≤ 3 points with abdominal pain and stool frequency no worse than Baseline) at Week 12.
Week 12
Change From Baseline in Simple Endoscopy Score for Crohn's Disease (SES-CD)
Time Frame: Baseline and Week 12
Assessment of change in simple endoscopy score for Crohn's Disease (SES-CD) from Baseline. Measure Description: The SES-CD evaluates 4 endoscopic variables (ulcer size, ulcerated surface, affected surface, and narrowing, each on a scale from 0 (none) to 3 in 5 segments assessed during ileocolonoscopy (ileum, right colon, transverse colon, sigmoid and left colon, and rectum). The total score is the sum of the 4 endoscopic variable scores and ranges from 0 to 56, where higher scores indicate more severe disease.
Baseline and Week 12
Serum Concentration of PRA023 (MK-7240)
Time Frame: Week 12
Blood samples were obtained for PK analysis of the serum concentration of PRA023 at week 12.
Week 12
Number of Participants Positive for Anti-drug Antibody (ADA)
Time Frame: Up to approximately 12 weeks
Blood samples were collected for the determination of anti-PR023 antibodies based on confirmatory assay. The number of participants with confirmed positive anti-PR023 antibodies results at any visit during the study is presented.
Up to approximately 12 weeks
Number of Participants With Positive Neutralizing Anti-Bodies (NAB)
Time Frame: Up to approximately 12 weeks
Blood samples were collected for the determination of NAB. The number of participants with positive NAB results at any visit during the study is presented.
Up to approximately 12 weeks

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Endoscopic Improvement and clinical remission by companion diagnostic (CDx) status
Time Frame: Week 12
Proportion of CDx+ participants achieving primary and key secondary efficacy outcome measures
Week 12

Collaborators and Investigators

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

Sponsor

Prometheus Biosciences, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA)

Investigators

  • Study Director: Medical Director, Merck Sharp & Dohme LLC

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

Helpful Links

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)

July 28, 2021

Primary Completion (Actual)

September 23, 2022

Study Completion (Actual)

May 27, 2025

Study Registration Dates

First Submitted

August 13, 2021

First Submitted That Met QC Criteria

August 13, 2021

First Posted (Actual)

August 19, 2021

Study Record Updates

Last Update Posted (Actual)

April 21, 2026

Last Update Submitted That Met QC Criteria

March 31, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • PR200-103 (Other Identifier: Prometheus Biosciences)
  • 2021-000092-37 (EudraCT Number)
  • 7240-006 (Other Identifier: MSD)
  • 2023-509742-35-00 (Registry Identifier: EU CT)
  • U1111-1309-6108 (Registry Identifier: UTN)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

Yes

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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