CD55-deficient Protein-losing EnteropathyPhase 2/3NCT04209634
Open-Label Efficacy and Safety Study of Pozelimab in Patients With CD55-Deficient Protein-Losing Enteropathy (CHAPLE Disease)
A Phase 2/3 study testing Pozelimab in people with CD55-deficient Protein-losing Enteropathy and CHAPLE, run by Regeneron Pharmaceuticals at 3 sites in 3 countries.
Trial summary
The primary objective of the study is to determine the effect of pozelimab on active CD55-deficient protein-losing enteropathy (PLE; CHAPLE). The secondary objectives of the study are: To evaluate the safety and tolerability of pozelimab in patients with CD55-deficient PLE disease To evaluate the effect of pozelimab… Read more about this study
- Who is it for?
- Ages 1 year and older
- Conditions the study is for
- CD55-deficient Protein-losing Enteropathy, CHAPLE
- What is being tested?
- Pozelimab
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 10 participants
- Where
- 3 sitesin 3 countries
- Study dates
- 27 Jan 2020to 2 May 2024
- Phase
- Phase 2/3
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Clinical diagnosis of CD55-deficient PLE/CHAPLE disease (based on a history of PLE), confirmed by biallelic CD55 loss-of-function mutation detected by genotype analysis
- Active disease as defined by the protocol or inactive disease on eculizumab therapy (and whose treating physician has the expectation of future access to renewed eculizumab treatment should this be required), and is willing to discontinue eculizumab during screening and start pozelimab at baseline with no eculizumab wash-out
Who cannot join
- History of meningococcal infection
- No documented meningococcal vaccination within 3 years prior to screening and patient unwilling to undergo vaccination during the study
- No documented vaccination for Haemophilus influenzae and Streptococcus pneumoniae if applicable based on local practice or guidelines prior to screening and patient unwilling to undergo vaccination during the study if required per local practice or guidelines
- Presence of a concomitant disease that leads to hypoproteinemia at the time of starting pozelimab
- A concomitant disease that leads to secondary intestinal lymphangiectasia such as a fontan procedure for congenital heart disease
- Note: Other protocol-defined Inclusion/Exclusion criteria apply.
Trial locations and contacts
3 sites in 3 countries.
3 sites in 3 countries
About this study
Official title: An Open-Label Efficacy and Safety Study of Pozelimab in Patients With CD55-Deficient Protein-Losing Enteropathy (CHAPLE Disease)
The primary objective of the study is to determine the effect of pozelimab on active CD55-deficient protein-losing enteropathy (PLE; CHAPLE).
The secondary objectives of the study are:
- To evaluate the safety and tolerability of pozelimab in patients with CD55-deficient PLE disease
- To evaluate the effect of pozelimab on CD55-deficient PLE (both patients with active disease at baseline and those with inactive disease on eculizumab, switching to pozelimab)
- To determine the effects of pozelimab on albumin and other serum proteins (total protein, immunoglobulins)
- To determine the effects of pozelimab on ascites
- To determine the effects of pozelimab on stool consistency
- To determine the effect of pozelimab on health-related quality of life
- To determine the effect of pozelimab on lab abnormalities observed in CD55-deficient PLE such as hypertriglyceridemia, thrombocytosis, and hypovitaminosis B12
- To describe the effects of pozelimab on the sparing of concomitant medications and reduction in hospitalization days
- To determine the effects of pozelimab on growth
- To characterize the concentration of pozelimab in patients with CD55-deficient PLE
- To assess the incidence of treatment-emergent ADA for pozelimab in patients with CD55-deficient PLE disease
- Conditions
- CD55-deficient Protein-losing Enteropathy, CHAPLE
- Being tested
- Pozelimab
- Keywords
- CD55-deficient PLE, complement hyperactivation, angiopathic thrombosis, protein-losing enteropathy (CHAPLE disease)
- 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 REGN3918
Single loading intravenous (IV) dose on day 1, then fixed doses sub-cutaneous (SC) (based on body weight) QW (±2 days) over the treatment period.
| Study group | Role | What they receive |
|---|---|---|
| Active PLE | Experimental | Patients aged 1 year and older with a clinical diagnosis of CD55-deficient PLE disease Receives: Drug: Pozelimab |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of Participants With Active Disease at Baseline Who Achieved Normalization of Serum Albumin and Improvement in Prespecified Clinical Outcomes at Week 24
Normalization of serum albumin was defined as serum albumin within the normal range at least 70 percent (%) of measurements between weeks 12 and 24, and no single albumin measurement of <2.5 grams per deciliter (g/dL) between weeks 12 and 24, and no requirement for albumin infusion between weeks 12 and 24. Improvement in the following 4 prespecified clinical outcomes that were evaluable for improvement at baseline, without worsening of the others: Daily bowel movement frequency, the presence and severity of facial edema (physician-reported), the presence and severity of peripheral edema (physician-reported), and the participant/caregiver assessment of frequency of problematic abdominal pain. Percentage of participants with active disease at baseline who achieved normalization of serum albumin and improvement in prespecified clinical outcomes at Week 24 were reported.
Measured: At Week 24
Secondary outcomes (57)
Number of Participants With Treatment-emergent Adverse Events (TEAEs) and Severity of TEAEs
TEAEs are defined as AEs that developed or worsened during the on-treatment period. The on-treatment period is defined as the time from first dose of investigational product up to 21 weeks after the last dose of investigational product. Severity of TEAEs was graded according to the following scale: Mild: Does not interfere in a significant manner with the patient's normal functioning level, Moderate: Produces some impairment of functioning but is not hazardous to health and Severe: Produces significant impairment of functioning or incapacitation and is a definite hazard to the participants health.
Measured: From start of study drug administration up to approximately 144 weeks
Number of Participants With Improvement in Most Bothersome Signs and Symptoms at Week 24
Improvement in most bothersome sign/symptom determined using semi-structured concept elicitation interview, from 'core' clinical endpoints of frequency of bowel movements, peripheral edema, facial edema, abdominal pain frequency, nausea, vomiting, stool consistency.
Measured: At Week 24
Number of Bowel Movements Per Day Based on a 1-week Average up to Week 24
Daily bowel movements captured by e-diary. The number of bowel movements per day was calculated each week of the study. It was based on a 1-week average and calculated as the sum of the number of bowel movements in a given week divided by the number of days with non-missing bowel movement frequency data. If more than 3 days of bowel movement data was missing in a given week, bowel movement frequency data was considered missing for that week.
Measured: Baseline, Weeks 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,12,13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 and 24
Number of Days Per Week With >=1 Bowel Movement of Loose/Watery Stool Consistency at Week 24
The number of days per week with >=1 loose/watery bowel movement, is calculated each week of the study as the sum of the number of days with >=1 loose/watery bowel movement in a given week divided by the number of days with non-missing stool consistency data and then multiplied by 7, is presented. If more than 3 days of stool consistency data was missing in a given week, stool consistency data was considered missing for that week.
Measured: Baseline, Weeks 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,12,13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 and 24
Number of Participants With Abdominal Ascites at Week 24
The measurement of abdominal ascites (excess abdominal fluid) was based on abdominal circumference. Abdominal circumference was measured regardless of the physician's assessment of the presence or absence of ascites.
Measured: Baseline up to Week 24
Absolute Value of Albumin at Specified Timepoints up to Week 24
Blood samples were collected from participants at defined time points for the assessment of albumin. Absolute value of albumin at specified timepoints was reported.
Measured: Baseline, Day 2, Weeks 1, 2, 3, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22 and 24
Absolute Values of Protein, and Immunoglobulin G (IgG) at Baseline and Week 24
Blood samples were collected from participants at defined time points for the assessment of protein and IgG. Absolutes values of protein and IgG measured as g/L at baseline and Week 24 was reported.
Measured: Baseline, Week 24
Absolute Values of Immunoglobulin (Ig), Immunoglobulin M (IgM), and Immunoglobulin A (IgA) at Baseline and Week 24
Blood samples were collected from participants at defined time points for the assessment of Ig, IgM and IgA. Absolute value of Ig, IgM and IgA measured as mg/dL at baseline and Week 24 was reported.
Measured: Baseline, Week 24
Absolute Values of Vitamin B12 at Baseline and Week 24
Blood samples were collected from participants at defined time points for the assessment of vitamin B12. Absolute values of vitamin B12 at baseline and Week 24 was reported.
Measured: Baseline, Week 24
Absolute Values of Iron and Unsaturated Iron Binding Capacity at Baseline and Week 24
Blood samples were collected from participants at defined time points for the assessment of iron indices. Absolute values of unsaturated iron and unsaturated iron binding capacity measured as micromoles per liter (mcmol/L) at baseline and Week 24 was reported.
Measured: Baseline, Week 24
Absolute Values of Vitamin B9 up to Week 24
Absolute Values of Vitamin B9 - Central Lab
Measured: Baseline up to Week 24
Absolute Values of Ferritin at Baseline and Week 24
Blood samples were collected from participants at defined time points for the assessment of iron indices. Absolute values of ferritin was reported.
Measured: Baseline, Week 24
Absolute Values of Magnesium, Total Cholesterol, and Triglycerides at Week 24
Blood samples were collected from participants at defined time points for the assessment of magnesium, total cholesterol, and triglycerides. Absolute values of magnesium, total cholesterol, and triglycerides measured as mmol/L at baseline and Week 24 was reported.
Measured: Baseline, Week 24
Change From Baseline in Alpha-1 Antitrypsin Levels in Stool at Week 12 and Week 24
Measured: Week 12, Week 24
Change From Baseline in Alpha-1 Antitrypsin Levels in Blood at Week 12 and Week 24
Measured: Week 12, Week 24
Percentage of Participants With Active Disease at Baseline Who Maintained Disease Control
Measured by normalization of serum albumin, no worsening of facial or peripheral edema, increase in bowel movement, or increase in abdominal pain frequency, no increase in dose of permitted concomitant medication for the treatment of PLE at any time as described in the protocol
Measured: Weeks 12 to 48; Weeks 12 to 144; Weeks 24 to 48; Weeks 48 to 96; Weeks 96 to 144
Change From Baseline in Physician Assessment of Facial Edema Based on a 5-point Likert Rating Scale
The physician assessment of facial edema is based on a 5-point Likert scale ranging from no edema (1) to very severe edema (5).
Measured: Baseline and Week 144
Change From Baseline in Physician Assessment of Peripheral Edema Based on a 5-point Likert Rating Scale
The physician assessment of peripheral edema is based on a 5-point Likert scale ranging from no edema (1) to very severe edema (5).
Measured: Baseline and Week 144
Change From Baseline in Food and Drink Limitations as Assessed by the PedsQL™ GI Symptom Scales' Food and Drink Limits Sub-scale
Frequency of limitations is assessed on a 5-point Likert response scale, ranging from never a problem (0) to almost always a problem (4). Items were reverse scored and linearly transformed to a 0 to 100 scale, where lower scores indicate more frequent problems with food and drink limitations.
Measured: Baseline and Week 144
Change From Baseline in Health-Related Quality of Life (HRQoL) as Assessed by the PedsQL™ Generic Core Scales
Physical functioning, emotional functioning, social functioning, and school/work/studies functioning is assessed using a 5-point Likert scale, ranging from never a problem (0) to almost always a problem (4). Items were reverse-scored and linearly transformed to a 0 to 100 scale, with higher scores indicating better HRQoL. The total scale score is computed as the sum of all the items over the number of items answered on individual scales. Subscale score is calculated as the sum of the items in the scale divided by the number of items answered in the scale.
Measured: Baseline and Week 144
Number of Participants With Albumin Infusion by 24 Week Periods
Measured: Weeks 0 to 24; Weeks 24 to 48; Weeks 48 to 72; Weeks 72 to 96; Weeks 96 to 120; Weeks 120 to 144
Change From Baseline in Albumin Values
Measured: Baseline and Week 144
Percentage Change From Baseline in Albumin Values
Measured: Baseline and Week 144
Time to First Normalization for Albumin Values
Measured: Baseline up to Week 144
Change From Baseline in Protein Values
Measured: Baseline and Week 144
Time to First Normalization for Total Protein
Measured: Baseline up to Week 144
Change From Baseline in Immunoglobulin (Ig) Values
Measured: Baseline and Week 144
Time to First Normalization for Ig Values
Measured: Baseline up to Week 144
Change From Baseline in IgG Values
Measured: Baseline and Week 144
Time to First Normalization for IgG Values
Measured: Baseline up to Week 144
Change From Baseline in IgM Values
Measured: Baseline and Week 144
Time to First Normalization for IgM Values
Measured: Baseline up to Week 44
Change From Baseline in IgA Values
Measured: Baseline and Week 144
Time to First Normalization for IgA Values
Measured: Baseline up to Week 144
Change From Baseline in Vitamin B12 Values
Measured: Baseline and Week 144
Time to First Normalization for Vitamin B12 Values
Measured: Baseline up to Week 144
Change From Baseline in Vitamin B9 (Folate) Values
Measured: Baseline and Week 144
Time to First Normalization for Vitamin B9 (Folate) Values
Measured: Baseline up to Week 144
Change From Baseline in Iron Values
Measured: Baseline and Week 144
Time to First Normalization for Iron Values
Measured: Baseline up to Week 144
Change From Baseline in Unsaturated Iron Binding Capacity
Measured: Baseline and Week 144
Time to First Normalization for Unsaturated Iron Binding Capacity
Measured: Baseline up to Week 144
Change From Baseline in Ferritin Values
Measured: Baseline and Week 144
Time to First Normalization for Ferritin Values
Measured: Baseline up to Week 144
Change From Baseline in Magnesium Values
Measured: Baseline and Week 144
Time to First Normalization for Magnesium Values
Measured: Baseline up to Week 144
Change From Baseline in Fasting Cholesterol Values
Measured: Baseline and Week 144
Time to First Normalization for Fasting Cholesterol Values
Measured: Baseline up to Week 144
Change From Baseline in Fasting Triglycerides Values
Measured: Baseline and Week 144
Time to First Normalization for Fasting Triglycerides Values
Measured: Baseline up to Week 144
Number of Participants Who Used Concomitant Medication
Measured: Baseline up to Week 144
Number of Hospitalization Days by 24 Week Period
Measured: Weeks 0 to 24; Weeks 24 to 48; Weeks 48 to 72; Weeks 72 to 96; Weeks 96 to 120; Weeks 120 to 144
Change From Baseline in Body Weight Z-Score
Weight-for-age z-score compares a participant's weight to children of the same age and sex from a healthy reference population. A z-score reflects an individual score as compared to a population mean and is expressed in units of standard deviation above (positive values) and below (negative values). Body weight z-score, regardless of magnitude, represents catch-up growth.
Measured: Baseline and Week 144
Change From Baseline in Height Z-Score
Height-for-age z-score compares a participant's height to children of the same age and sex from a healthy reference population. A z-score reflects an individual score as compared to a population mean and is expressed in units of standard deviation above (positive values) and below (negative values). Any increase in height z-score, regardless of magnitude, represents catch-up growth.
Measured: Baseline and Week 144
Change From Baseline in Total Complement Activity Complement Hemolytic Assay (CH50)
Measured: Baseline and Week 144
Concentrations of Total Pozelimab in Serum
Measured: Baseline up to Week 164
Number of Participants With Treatment-emergent Anti-drug Antibodies (ADA) to Pozelimab
Measured: Baseline up to Week 164
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Dec 2019
- Study start27 Jan 2020
- Primary completion9 Nov 2021
- Study completion2 May 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for CD55-deficient Protein-losing EnteropathyStudies 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 2/3
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 10 participants (actual)
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
- NCT04209634
- Sponsor's protocol ID
- R3918-PLE-1878
- Status last verified
- Aug 2025
- First submitted
- 20 Dec 2019
- Last updated
- 29 Aug 2025
- Results posted
- Yes, on ClinicalTrials.gov
- 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
Publications
Litcher-Kelly L, Ozen A, Ollis S, Feldman HB, Yaworsky A, Medrano P, Chongsrisawat V, Perlee L, Walker M, Pradeep S, Turner-Bowker DM, Kurolap A, Adiv OE, Lenardo MJ, Harari OA, Jalbert JJ. The patient experience of CHAPLE disease: results from interviews conducted as part of a clinical trial for an ultra-rare condition. Orphanet J Rare Dis. 2025 Feb 11;20(1):68. doi: 10.1186/s13023-024-03436-y.
PubMed 39934837Can S, Yorgun Altunbas M, Ozen A. An evaluation of pozelimab for the treatment of CHAPLE disease. Expert Opin Biol Ther. 2025 Jan;25(1):1-7. doi: 10.1080/14712598.2024.2438740. Epub 2024 Dec 12.
PubMed 39657032Litcher-Kelly L, Ozen A, Ollis S, Feldman HB, Yaworsky A, Medrano P, Chongsrisawa V, Brackin T, Perlee L, Walker M, Pradeep S, Lenardo MJ, Harari OA, Jalbert JJ. Pozelimab for CHAPLE disease: results from in-trial interviews and clinical outcome assessments. Orphanet J Rare Dis. 2024 Aug 8;19(1):290. doi: 10.1186/s13023-024-03277-9.
PubMed 39118150Ozen A, Chongsrisawat V, Sefer AP, Kolukisa B, Jalbert JJ, Meagher KA, Brackin T, Feldman HB, Baris S, Karakoc-Aydiner E, Ergelen R, Fuss IJ, Moorman H, Suratannon N, Suphapeetiporn K, Perlee L, Harari OA, Yancopoulos GD, Lenardo MJ; Pozelimab CHAPLE Working Group. Evaluating the efficacy and safety of pozelimab in patients with CD55 deficiency with hyperactivation of complement, angiopathic thrombosis, and protein-losing enteropathy disease: an open-label phase 2 and 3 study. Lancet. 2024 Feb 17;403(10427):645-656. doi: 10.1016/S0140-6736(23)02358-9. Epub 2024 Jan 23.
PubMed 38278170
Study at a glance
From the registry record, last updated by the sponsor on 29 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open-Label Efficacy and Safety Study of Pozelimab in Patients With CD55-Deficient Protein-Losing Enteropathy (CHAPLE Disease)
- ClinicalTrials.gov ID
- NCT04209634
- Acronym / sponsor ID
- R3918-PLE-1878
- Conditions
- CD55-deficient Protein-losing Enteropathy, CHAPLE
- Keywords
- CD55-deficient PLE, complement hyperactivation, angiopathic thrombosis, protein-losing enteropathy (CHAPLE disease)
- Phase
- Phase 2/3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 10 participants (actual)
- Lead sponsor
- Regeneron PharmaceuticalsIndustry (pharma, biotech, devices)
- Study start
- 27 Jan 2020 (actual)
- Primary completion
- 9 Nov 2021 (actual)
- Study completion
- 2 May 2024 (actual)
- First posted
- 24 Dec 2019 (actual)
- Results
- Posted 30 Oct 2023
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The primary objective of the study is to determine the effect of pozelimab on active CD55-deficient protein-losing enteropathy (PLE; CHAPLE).
The secondary objectives of the study are:
- To evaluate the safety and tolerability of pozelimab in patients with CD55-deficient PLE disease
- To evaluate the effect of pozelimab on CD55-deficient PLE (both patients with active disease at baseline and those with inactive disease on eculizumab, switching to pozelimab)
- To determine the effects of pozelimab on albumin and other serum proteins (total protein, immunoglobulins)
- To determine the effects of pozelimab on ascites
- To determine the effects of pozelimab on stool consistency
- To determine the effect of pozelimab on health-related quality of life
- To determine the effect of pozelimab on lab abnormalities observed in CD55-deficient PLE such as hypertriglyceridemia, thrombocytosis, and hypovitaminosis B12
- To describe the effects of pozelimab on the sparing of concomitant medications and reduction in hospitalization days
- To determine the effects of pozelimab on growth
- To characterize the concentration of pozelimab in patients with CD55-deficient PLE
- To assess the incidence of treatment-emergent ADA for pozelimab in patients with CD55-deficient PLE disease
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Active PLE | Experimental | Drug: PozelimabPatients aged 1 year and older with a clinical diagnosis of CD55-deficient PLE disease |
Who may qualify
- Ages
- 1 year and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (2 listed)
- Clinical diagnosis of CD55-deficient PLE/CHAPLE disease (based on a history of PLE), confirmed by biallelic CD55 loss-of-function mutation detected by genotype analysis
- Active disease as defined by the protocol or inactive disease on eculizumab therapy (and whose treating physician has the expectation of future access to renewed eculizumab treatment should this be required), and is willing to discontinue eculizumab during screening and start pozelimab at baseline with no eculizumab wash-out
Key exclusion criteria (6 listed)
- History of meningococcal infection
- No documented meningococcal vaccination within 3 years prior to screening and patient unwilling to undergo vaccination during the study
- No documented vaccination for Haemophilus influenzae and Streptococcus pneumoniae if applicable based on local practice or guidelines prior to screening and patient unwilling to undergo vaccination during the study if required per local practice or guidelines
- Presence of a concomitant disease that leads to hypoproteinemia at the time of starting pozelimab
- A concomitant disease that leads to secondary intestinal lymphangiectasia such as a fontan procedure for congenital heart disease
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: REGN3918Single loading intravenous (IV) dose on day 1, then fixed doses sub-cutaneous (SC) (based on body weight) QW (±2 days) over the treatment period. | Drug | Active PLE |
Primary outcome
Percentage of Participants With Active Disease at Baseline Who Achieved Normalization of Serum Albumin and Improvement in Prespecified Clinical Outcomes at Week 24
Time frame: At Week 24
Normalization of serum albumin was defined as serum albumin within the normal range at least 70 percent (%) of measurements between weeks 12 and 24, and no single albumin measurement of <2.5 grams per deciliter (g/dL) between weeks 12 and 24, and no requirement for albumin infusion between weeks 12 and 24. Improvement in the following 4 prespecified clinical outcomes that were evaluable for improvement at baseline, without worsening of the others: Daily bowel movement frequency, the presence and severity of facial edema (physician-reported), the presence and severity of peripheral edema (physician-reported), and the participant/caregiver assessment of frequency of problematic abdominal pain. Percentage of participants with active disease at baseline who achieved normalization of serum albumin and improvement in prespecified clinical outcomes at Week 24 were reported.
57 secondary outcomes
Number of Participants With Treatment-emergent Adverse Events (TEAEs) and Severity of TEAEs
Time frame: From start of study drug administration up to approximately 144 weeks
Number of Participants With Improvement in Most Bothersome Signs and Symptoms at Week 24
Time frame: At Week 24
Number of Bowel Movements Per Day Based on a 1-week Average up to Week 24
Time frame: Baseline, Weeks 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,12,13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 and 24
Number of Days Per Week With >=1 Bowel Movement of Loose/Watery Stool Consistency at Week 24
Time frame: Baseline, Weeks 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,12,13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 and 24
Number of Participants With Abdominal Ascites at Week 24
Time frame: Baseline up to Week 24
Absolute Value of Albumin at Specified Timepoints up to Week 24
Time frame: Baseline, Day 2, Weeks 1, 2, 3, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22 and 24
Absolute Values of Protein, and Immunoglobulin G (IgG) at Baseline and Week 24
Time frame: Baseline, Week 24
Absolute Values of Immunoglobulin (Ig), Immunoglobulin M (IgM), and Immunoglobulin A (IgA) at Baseline and Week 24
Time frame: Baseline, Week 24
Absolute Values of Vitamin B12 at Baseline and Week 24
Time frame: Baseline, Week 24
Absolute Values of Iron and Unsaturated Iron Binding Capacity at Baseline and Week 24
Time frame: Baseline, Week 24
Absolute Values of Vitamin B9 up to Week 24
Time frame: Baseline up to Week 24
Absolute Values of Ferritin at Baseline and Week 24
Time frame: Baseline, Week 24
Absolute Values of Magnesium, Total Cholesterol, and Triglycerides at Week 24
Time frame: Baseline, Week 24
Change From Baseline in Alpha-1 Antitrypsin Levels in Stool at Week 12 and Week 24
Time frame: Week 12, Week 24
Change From Baseline in Alpha-1 Antitrypsin Levels in Blood at Week 12 and Week 24
Time frame: Week 12, Week 24
Percentage of Participants With Active Disease at Baseline Who Maintained Disease Control
Time frame: Weeks 12 to 48; Weeks 12 to 144; Weeks 24 to 48; Weeks 48 to 96; Weeks 96 to 144
Change From Baseline in Physician Assessment of Facial Edema Based on a 5-point Likert Rating Scale
Time frame: Baseline and Week 144
Change From Baseline in Physician Assessment of Peripheral Edema Based on a 5-point Likert Rating Scale
Time frame: Baseline and Week 144
Change From Baseline in Food and Drink Limitations as Assessed by the PedsQL™ GI Symptom Scales' Food and Drink Limits Sub-scale
Time frame: Baseline and Week 144
Change From Baseline in Health-Related Quality of Life (HRQoL) as Assessed by the PedsQL™ Generic Core Scales
Time frame: Baseline and Week 144
Number of Participants With Albumin Infusion by 24 Week Periods
Time frame: Weeks 0 to 24; Weeks 24 to 48; Weeks 48 to 72; Weeks 72 to 96; Weeks 96 to 120; Weeks 120 to 144
Change From Baseline in Albumin Values
Time frame: Baseline and Week 144
Percentage Change From Baseline in Albumin Values
Time frame: Baseline and Week 144
Time to First Normalization for Albumin Values
Time frame: Baseline up to Week 144
Change From Baseline in Protein Values
Time frame: Baseline and Week 144
Time to First Normalization for Total Protein
Time frame: Baseline up to Week 144
Change From Baseline in Immunoglobulin (Ig) Values
Time frame: Baseline and Week 144
Time to First Normalization for Ig Values
Time frame: Baseline up to Week 144
Change From Baseline in IgG Values
Time frame: Baseline and Week 144
Time to First Normalization for IgG Values
Time frame: Baseline up to Week 144
Change From Baseline in IgM Values
Time frame: Baseline and Week 144
Time to First Normalization for IgM Values
Time frame: Baseline up to Week 44
Change From Baseline in IgA Values
Time frame: Baseline and Week 144
Time to First Normalization for IgA Values
Time frame: Baseline up to Week 144
Change From Baseline in Vitamin B12 Values
Time frame: Baseline and Week 144
Time to First Normalization for Vitamin B12 Values
Time frame: Baseline up to Week 144
Change From Baseline in Vitamin B9 (Folate) Values
Time frame: Baseline and Week 144
Time to First Normalization for Vitamin B9 (Folate) Values
Time frame: Baseline up to Week 144
Change From Baseline in Iron Values
Time frame: Baseline and Week 144
Time to First Normalization for Iron Values
Time frame: Baseline up to Week 144
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Aug 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 39934837Litcher-Kelly L, Ozen A, Ollis S, Feldman HB, Yaworsky A, Medrano P, Chongsrisawat V, Perlee L, Walker M, Pradeep S, Turner-Bowker DM, Kurolap A, Adiv OE, Lenardo MJ, Harari OA, Jalbert JJ. The patient experience of CHAPLE disease: results from interviews conducted as part of a clinical trial for an ultra-rare condition. Orphanet J Rare Dis. 2025 Feb 11;20(1):68. doi: 10.1186/s13023-024-03436-y.
- Derived from this study: PubMed 39657032Can S, Yorgun Altunbas M, Ozen A. An evaluation of pozelimab for the treatment of CHAPLE disease. Expert Opin Biol Ther. 2025 Jan;25(1):1-7. doi: 10.1080/14712598.2024.2438740. Epub 2024 Dec 12.
- Derived from this study: PubMed 39118150Litcher-Kelly L, Ozen A, Ollis S, Feldman HB, Yaworsky A, Medrano P, Chongsrisawa V, Brackin T, Perlee L, Walker M, Pradeep S, Lenardo MJ, Harari OA, Jalbert JJ. Pozelimab for CHAPLE disease: results from in-trial interviews and clinical outcome assessments. Orphanet J Rare Dis. 2024 Aug 8;19(1):290. doi: 10.1186/s13023-024-03277-9.
- Derived from this study: PubMed 38278170Ozen A, Chongsrisawat V, Sefer AP, Kolukisa B, Jalbert JJ, Meagher KA, Brackin T, Feldman HB, Baris S, Karakoc-Aydiner E, Ergelen R, Fuss IJ, Moorman H, Suratannon N, Suphapeetiporn K, Perlee L, Harari OA, Yancopoulos GD, Lenardo MJ; Pozelimab CHAPLE Working Group. Evaluating the efficacy and safety of pozelimab in patients with CD55 deficiency with hyperactivation of complement, angiopathic thrombosis, and protein-losing enteropathy disease: an open-label phase 2 and 3 study. Lancet. 2024 Feb 17;403(10427):645-656. doi: 10.1016/S0140-6736(23)02358-9. Epub 2024 Jan 23.
- A Plain Language Summary is available on TrialSummaries.comLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing
Related trials for CD55-deficient Protein-losing Enteropathy
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. This study is not recruiting at the moment.
Clinical Trial Management study director
Regeneron Pharmaceuticals
3 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2/3 study testing Pozelimab in people with CD55-deficient Protein-losing Enteropathy and CHAPLE, run by Regeneron Pharmaceuticals at 3 sites in 3 countries.
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 2 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: finished, as of the sponsor's last update on 29 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in United States, Thailand, 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 combined phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 30 Oct 2023). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Percentage of Participants With Active Disease at Baseline Who Achieved Normalization of Serum Albumin and Improvement in Prespecified Clinical Outcomes at Week 24 (time frame: At Week 24). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04209634, which also lists 4 linked publications.
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 29 Aug 2025.