A Study to Test the Safety of Pozelimab in Pediatric Participants 1 to 5 Years of Age With a Rare Disease Called CHAPLE (Complement Hyperactivation, Angiopathic Thrombosis, Protein-losing Enteropathy) Disease

NCT07142343 | Recruiting Phase 4 FDA Drug

• 1 other identifier: R3918-PLE-2399
• Study Type: interventional
• Target: 5
• Locations: 1 country
• Sites: 1

Brief Summary

This study is researching a drug called pozelimab (called "study drug"). The main aim of this study is to monitor the safety and tolerability of the study drug. The study is focused on young children 1 to 5 years of age, who have CHAPLE disease. CHAPLE is a very rare hereditary disease that can cause potentially life-threatening symptoms related to the stomach and intestines (gastrointestinal symptoms), and symptoms related to the heart and blood vessels (cardiovascular symptoms). The study is also looking at several other research questions, including:

• What side effects may happen from taking the study drug
• How much study drug is in the blood at different times
• Whether the study drug blocks Complement 5 (C5) in the body
• Whether the study drug changes the level of a substance called CH50 measured in the blood
• Whether the study drug changes the levels of albumin and other proteins
• Whether the body makes antibodies against study drug, which could make the study drug less effective or could lead to side effects

Conditions

CHAPLE Disease

Keywords

CD55-deficient PLE (CHAPLE disease); CD55 loss-of-function mutation; Complement hyperactivation; Angiopathic thrombosis; Protein-losing enteropathy; Total Complement Hemolytic Activity Assay (CH50)

Outcome Measures

Primary Outcomes (2)

• Incidence of Treatment-Emergent Adverse Event (TEAEs)

  Through week 52

• Severity of TEAEs

  Through week 52

Secondary Outcomes (12)

• Concentrations of total pozelimab

  Through week 52

• Concentrations of total C5 in serum

  Through week 52

• Absolute change from baseline of albumin concentration in serum

  Through week 52

• Percent change from baseline of albumin concentration in serum

  Through week 52

• Absolute change from baseline of total protein

  Through week 52

Study Arms (1)

Active CHAPLE

EXPERIMENTAL

Drug: Pozelimab

Interventions

Pozelimab DRUG

Administered per the protocol

Also known as: VEOPOZ

Active CHAPLE

Eligibility Criteria

• Age: 1 Year - 5 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Clinical diagnosis of CD55-deficient CHAPLE disease as described in the protocol
• Parent(s)/legal guardian(s) are willing and able to comply with participant's clinic visits and study-related procedures, including participant's completion of the full series of meningococcal vaccinations required per protocol.
• Parent(s)/legal guardian(s) are willing to provide written informed consent
• Participant has active CHAPLE disease as described in the protocol

You may not qualify if:

• History of meningococcal infection
• No documented meningococcal quadrivalent (serotype ACWY) vaccination prior to screening and participant's parent(s)/legal guardian(s) are unwilling for participant to undergo vaccination during the study as described in the protocol
• No documented vaccination for Haemophilus influenzae and Streptococcus pneumoniae if applicable based on local practice or guidelines prior to screening as described in the protocol
• Prior treatment with a complement inhibitor as described in the protocol
• Presence of a concomitant disease that leads to hypoproteinemia or secondary intestinal lymphangiectasia as described in the protocol

Sponsors & Collaborators

• Regeneron Pharmaceuticals: lead

Study Sites (1)

Marmara University Hospital

Istanbul, 10 34899, Turkey (Türkiye)

RECRUITING

MeSH Terms

Conditions

Protein-Losing Enteropathies

Condition Hierarchy (Ancestors)

Intestinal Diseases; Gastrointestinal Diseases; Digestive System Diseases

Study Officials

• Clinical Trial Management

  Regeneron Pharmaceuticals

  STUDY DIRECTOR

Central Study Contacts

Clinical Trials Administrator

CONTACT

844-734-6643; clinicaltrials@regeneron.com

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 19, 2025
• First Posted: August 26, 2025
• Study Start: March 19, 2026
• Primary Completion (Estimated): February 12, 2030
• Study Completion (Estimated): February 12, 2030
• Last Updated: April 13, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR, ANALYTIC CODE
• Time Frame: When Regeneron has: * received marketing authorization from major health authorities (e.g., FDA, European Medicines Agency (EMA), Pharmaceuticals and Medical Devices Agency (PMDA), etc.) for the product and indication or has globally discontinued development of the product for all indications on or after April 2020 and has no plans for future development * made results publicly available (e.g., scientific publication, scientific conference, clinical trial registry) * the legal authority to share the data, and * ensured the ability to protect participant privacy
• Access Criteria: Qualified researchers can submit a proposal for access to individual patient or aggregate level data from a Regeneron-sponsored clinical trial through Vivli. Regeneron's Independent Research Request Evaluation Criteria can be found at: https://www.regeneron.com/sites/default/files/Regeneron-External-Data-Sharing-Policy-and-Independent-Research-Request-Evaluation-Criteria.pdf

Locations

TU (1)