A Phase 3, Multicenter, Randomized, Platform Study of p19 Inhibition of the IL-23 Pathway to Establish Efficacy in Pediatric Crohn’s Disease (MACARONI-23)
Published: 11/19/2025
General Information:
To evaluate two different drugs that block IL-23 pathway in the immune system are safe and effective to treat moderate to severe pediatric Crohn’s disease. These two drugs will not be compared against each other.
Eligibility:
Inclusion Criteria:
- Be at least 2 years old to 17 years old at the time you enter the study
- Have moderate to severe Crohn’s disease (CD)
- Have tried a treatment in the past that no longer controls your CD
- Have not been able to tolerate other treatments for your CD
Exclusion Criteria:
- Cannot have ulcerative colitis or indeterminate colitis
- Cannot have complications of CD such as symptomatic strictures or stenosis, short gut syndrome, or any issue or problem that may require surgery in the near future
- Cannot have an abscess
- Cannot have had any kind of bowel surgery within the last 6 months
Study Details:
Study description/explanation of participation :
This study will include about 210 children (2 to 17 years of age) in many countries around the world.
The active treatment phase of the study will take approximately 52 weeks and you will receive the study drug at the study center appointments, either by injection under the skin (subcutaneous) or into a vein (intravenous).
If you are doing well at the end of the study, you may be eligible to keep receiving the study drug by moving to another study.
Description of treatment or intervention (mechanism of action):
Inflammation in your colon and GI tract contributes significantly to the development and ongoing disease activity of CD. A protein called IL-23 works with immune cells to increase inflammation.
The investigational therapies developed by Janssen and Eli Lilly work by blocking IL-23, a key component of inflammation.
Patient Participation Requirements:
If you take part, you will be in the MACARONI-23 Study for about 1.5 years. During this study, you will be asked to:
- Attend regular appointments at the study center (with your parent/caregiver) for assessments to check your health. In the beginning, you will come to the study center at least 2 times for various initial tests to see if the study is suitable for you.
- If the initial tests show that this study is suitable for you, you will be randomly assigned (by a computer) to receive 1 of the 2 study drugs and will enter the next stage of the study. You will receive study drug at each visit. Once you are assigned to the study you will stay on that drug for the entire study.
- Have blood, stool, and urine tests to check your health a few times during the study.
- Have up to 2 endoscopies, which may be with biopsies. A biopsy is where a tiny piece of the intestines – part of the digestive tract – is removed for testing.
- Complete daily electronic diary entries (eDiary) about your CD symptoms and how you feel. You will also answer questions on a tablet when you come to your regular appointments about how your symptoms and how your quality of life is.
Possible risks and side effects:
You may experience side effects as part of receiving the investigational therapies. These risks and side effects may differ based on the study drug that you receive. Eli Lilly and Janssen are working to characterize the profile of these risks based on ongoing studies and will alert trial participants on any changes in the known side effect profile.
Progress to date:
This study is being conducted to provide information on how these drugs work in pediatric trial participants. If you would like to know more about these investigational therapies, you can discuss with your health care provider.