CHAPLE DiseasePhase 4NCT07142343
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
A Phase 4 study testing Pozelimab in people with CHAPLE Disease, run by Regeneron Pharmaceuticals at 1 site in Turkey (Türkiye).
Trial 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. Read more about this study
- Who is it for?
- Ages 1 year to 5 years
- Conditions the study is for
- CHAPLE Disease
- What is being tested?
- Pozelimab
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 5 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 19 Mar 2026to 12 Feb 2030
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 1 year to 5 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- 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
Who cannot join
- 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
- Note: Other Protocol Defined Inclusion/ Exclusion Criteria Apply
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Marmara University Hospital
Istanbul, 10 34899
About this study
Official title: An Open-Label, Single-Arm Study Evaluating the Safety, Pharmacokinetics, Pharmacodynamics, and Immunogenicity of Pozelimab in Pediatric Patients 1 to 5 Years of Age With CD55-Deficient Protein-Losing Enteropathy (CHAPLE Disease)
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).
Read more
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
- Being tested
- Pozelimab
- Keywords
- CD55-deficient PLE (CHAPLE disease), CD55 loss-of-function mutation, Complement hyperactivation, Angiopathic thrombosis, Protein-losing enteropathy, Total Complement Hemolytic Activity Assay (CH50)
- Medical subject headings
- Protein-Losing Enteropathies
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PozelimabDrug
Also called VEOPOZ
Administered per the protocol
| Study group | Role | What they receive |
|---|---|---|
| Active CHAPLE | Experimental | Not described Receives: Drug: Pozelimab |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of Treatment-Emergent Adverse Event (TEAEs)
Measured: Through week 52
Severity of TEAEs
Measured: Through week 52
Secondary outcomes (12)
Concentrations of total pozelimab
Measured: Through week 52
Concentrations of total C5 in serum
Measured: Through week 52
Absolute change from baseline of albumin concentration in serum
Measured: Through week 52
Percent change from baseline of albumin concentration in serum
Measured: Through week 52
Absolute change from baseline of total protein
Measured: Through week 52
Percent change from baseline of total protein
Measured: Through week 52
Absolute change from baseline of total Immunoglobulin G (IgG)
Measured: Through week 52
Percent change from baseline of total IgG
Measured: Through week 52
Incidence of Anti-Drug Antibody (ADA) to pozelimab over time
Measured: Through week 52
Titer of ADA to pozelimab over time
Measured: Through week 52
Change from baseline of total complement activity CH50 over time
Measured: Through week 52
Percent change from baseline of CH50 over time
Measured: Through week 52
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Aug 2025
- Study start19 Mar 2026
- Primary completion12 Feb 2030 (estimated)
- Study completion12 Feb 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for CHAPLE DiseaseStudies of the same condition, open and under way.
- More trials run by Regeneron PharmaceuticalsThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 5 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Regeneron Pharmaceuticals
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Clinical Trial Management, Study director, Regeneron Pharmaceuticals
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07142343
- Sponsor's protocol ID
- R3918-PLE-2399
- Status last verified
- Apr 2026
- First submitted
- 19 Aug 2025
- Last updated
- 13 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing
Study at a glance
From the registry record, last updated by the sponsor on 13 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open-Label, Single-Arm Study Evaluating the Safety, Pharmacokinetics, Pharmacodynamics, and Immunogenicity of Pozelimab in Pediatric Patients 1 to 5 Years of Age With CD55-Deficient Protein-Losing Enteropathy (CHAPLE Disease)
- ClinicalTrials.gov ID
- NCT07142343
- Acronym / sponsor ID
- R3918-PLE-2399
- 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)
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 5 participants (estimated)
- Lead sponsor
- Regeneron PharmaceuticalsIndustry (pharma, biotech, devices)
- Study start
- 19 Mar 2026 (actual)
- Primary completion
- 12 Feb 2030 (estimated)
- Study completion
- 12 Feb 2030 (estimated)
- First posted
- 26 Aug 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Active CHAPLE | Experimental | Drug: Pozelimab |
Who may qualify
- Ages
- 1 year to 5 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (4 listed)
- 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
Key exclusion criteria (6 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PozelimabAlso: VEOPOZAdministered per the protocol | Drug | Active CHAPLE |
Primary outcome
Incidence of Treatment-Emergent Adverse Event (TEAEs)
Time frame: Through week 52
Severity of TEAEs
Time frame: Through week 52
12 secondary outcomes
Concentrations of total pozelimab
Time frame: Through week 52
Concentrations of total C5 in serum
Time frame: Through week 52
Absolute change from baseline of albumin concentration in serum
Time frame: Through week 52
Percent change from baseline of albumin concentration in serum
Time frame: Through week 52
Absolute change from baseline of total protein
Time frame: Through week 52
Percent change from baseline of total protein
Time frame: Through week 52
Absolute change from baseline of total Immunoglobulin G (IgG)
Time frame: Through week 52
Percent change from baseline of total IgG
Time frame: Through week 52
Incidence of Anti-Drug Antibody (ADA) to pozelimab over time
Time frame: Through week 52
Titer of ADA to pozelimab over time
Time frame: Through week 52
Change from baseline of total complement activity CH50 over time
Time frame: Through week 52
Percent change from baseline of CH50 over time
Time frame: Through week 52
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Apr 2026.
- Individual participant dataSharing planned: Yes. All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Clinical Trial Management study director
Regeneron Pharmaceuticals
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Pozelimab in people with CHAPLE Disease, run by Regeneron Pharmaceuticals at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 13 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Clinical Trials Administrator (844-734-6643, clinicaltrials@regeneron.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of Treatment-Emergent Adverse Event (TEAEs) (time frame: Through week 52). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Apr 2026.