Comparing Pozelimab with Cemdisiran for paroxysmal nocturnal hemoglobinuria
Official title: A Study in Adult Patients With Paroxysmal Nocturnal Hemoglobinuria (PNH) to Evaluate How Safe Long-term Treatment With Pozelimab + Cemdisiran Combination Therapy is and How Well it Works
An Open-Label Extension Study to Evaluate the Long-Term Safety, Tolerability, and Efficacy of Pozelimab and Cemdisiran Combination Therapy in Patients With Paroxysmal Nocturnal Hemoglobinuria
- Phase 3
- 2 groups
- One site, in Toronto
- Recruiting
Interventions
- Medication
Pozelimab
Administered per the protocol
- Medication
Cemdisiran
Administered per the protocol
Canadian Sites (1)
1 of 1 recruiting
- Recruiting
Toronto General Hospital
Toronto, Ontario
Eligibility Criteria
See who this study is looking for22 criteria
The trial’s own eligibility text, word for word from the registry. Only the trial site can say who takes part.
Inclusion
- +Patients Entering from the Parent Study
- +Patients with PNH who have completed, without permanent discontinuation, study treatment in the parent study (R3918-PNH-2021\[NCT05133531\]), including the post-Open-labelOpen-labelEveryone knows which treatment is being given — nothing is hidden.Read more → treatment period (OLTP) transition period, if applicable.
- +Willing and able to comply with clinic visits and study-related procedures, including meningococcal vaccinations required per protocolProtocolThe detailed plan a study must follow.Read more →.
- +Patients Entering with C5 polymorphism
- +Patients with PNH who have a documented C5 polymorphism rendering them refractory to eculizumab or ravulizumab (eg, p.Arg885His, p.Arg885Cys), as described in the protocol
- +Diagnosis of PNH confirmed by high-sensitivity flow cytometry testing with PNH granulocytes or monocytes
- +Active disease, as defined by the presence of 1 or more PNH-related sign or symptom as described in the protocol
- +LDH level ≥2 × upper limit of normal (ULN) at the screening visitScreeningThe checks done before joining, to see whether a study fits.Read more →
- +Willing and able to comply with clinic visits and study-related procedures, including meningococcal vaccinations required per protocol
Exclusion
- −Positive hepatitis B surface antigen or hepatitis C virus Ribonucleic acid (RNA) during screeningScreeningThe checks done before joining, to see whether a study fits.Read more →
- −Patients with known HIV with history of opportunistic infections in the last 1 year as described in the protocolProtocolThe detailed plan a study must follow.Read more →
- −Patients Entering from the Parent Study
- −Significant protocol deviation(s) in the parent study based on the investigatorPrincipal investigatorThe doctor or researcher responsible for running the study at a site.Read more →'s judgment and to the extent that these would (if continued) impact the study objectives and/or safety of the patient
- −Any new condition or worsening of an existing condition which, in the opinion of the investigator, would make the patient unsuitable for enrollmentEnrolmentThe number of participants a study plans to include, or has included.Read more → or could interfere with the patient participating in or completing the study
- −Patients Entering with C5 polymorphism
- −Prior treatment with complement inhibitors within 5 half-lives of the respective agent prior to screening, except for prior eculizumab or ravulizumab which are not exclusionary
- −Receipt of an organ transplant, history of bone marrow transplantation or other hematologic transplant
- −Not meeting meningococcal vaccination requirements and, at a minimum, documentation of quadrivalent meningococcal vaccination within 5 years prior to enrollment and serotype B vaccine within 3 years prior to enrollment as described in the protocol
- −Known hereditary complement deficiency
- −Documented history of active, uncontrolled, ongoing systemic autoimmune diseases
- −Documented history of liver cirrhosis or patients with liver disease with evidence of current impaired liver function or patients with elevations in Alanine aminotransferase (ALT) or Aspartate aminotransferase (AST) (unrelated to PNH or its complications) as described in the protocol
- −Note: Other protocol-defined InclusionInclusion criteriaThe things you must have or be for a study to consider you.Read more →/ Exclusion CriteriaExclusion criteriaThe things that would prevent someone from taking part.Read more → apply
In plain language
Assembled directly from this trial’s registry record. Every sentence traces to a field below — nothing here is generated or interpreted.
What this study is
This study is testing a treatment for a condition.
Phase 3Phase 3A large study comparing a treatment against the current standard.Read more → — a large study comparing this against the current standard, usually across many hospitals.
From the trial registry
Built from these fields:
- designModule.designInfo.primaryPurpose
- designModule.phases
Who receives what
There are 2 groups in this study.
Groups A and B receive one or more of: Pozelimab and Cemdisiran.
Registry label: A: PNH Transition Patients · B: C5 Polymorphism Patients
From the trial registry
Built from these fields:
- armsInterventionsModule.armGroups[].label
- armsInterventionsModule.armGroups[].type
- armsInterventionsModule.armGroups[].interventionNames
How the study is run
Groups are assigned by the study team using set rules, rather than by chance.
This study is open-labelOpen-labelEveryone knows which treatment is being given — nothing is hidden.Read more →: everyone knows which treatment is being given, including you and the study team.
From the trial registry
Built from these fields:
- designModule.designInfo.allocation
- designModule.designInfo.maskingInfo.masking
Is there a placebo?
This study does not list a placeboPlaceboA dummy treatment with no active medicine, used for comparison.Read more → group.
From the trial registry
Built from these fields:
- armsInterventionsModule.armGroups[].type
- armsInterventionsModule.armGroups[].interventionNames
Who the study is looking for
The study lists a minimum age of 18 years, with no upper limit given.
The study is open to people of any sex.
The study does not accept healthy volunteersHealthy volunteerSomeone without the condition being studied who takes part anyway.Read more →.
These are the criteria the study lists. Only the trial siteTrial siteA hospital or clinic where a study is actually run.Read more → can decide whether someone can take part.
From the trial registry
Built from these fields:
- eligibilityModule.minimumAge
- eligibilityModule.sex
- eligibilityModule.healthyVolunteers
How big and how long
The study aims to enrol about 202 people.
The study is currently expected to finish around October 2028.
The main measurement is taken over: Up to week 108.
From the trial registry
Built from these fields:
- designModule.enrollmentInfo.count
- statusModule.completionDateStruct.date
- outcomesModule.primaryOutcomes[].timeFrame
What the study measures
Incidence of treatment-emergent serious adverse eventsSerious adverse eventAn adverse event meeting a formal severity threshold, such as requiring hospital admission.Read more → (SAEs) — measured over Up to week 108.
Severity of treatment-emergent SAEs — measured over Up to week 108.
Incidence of treatment emergent adverse eventsAdverse eventAny medical problem that happens during a study, whether or not the treatment caused it.Read more → of special interest (AESIs) — measured over Up to week 108.
Severity of treatment emergent AESIs — measured over Up to week 108.
The study lists 3 further main measurements.
From the trial registry
Built from these fields:
- outcomesModule.primaryOutcomes[].measure
- outcomesModule.primaryOutcomes[].timeFrame
Source: NCT05744921 on ClinicalTrials.gov. The full registry text is further down this page — this summary never replaces it.
Not medical advice. What do these terms mean?
What is being tested — in plain terms
About PozelimabDrug
Administered per the protocol
From the trial registry — its own words, unedited.
What a drug is here: A medicine — a chemical or small-molecule treatment — given as the thing being studied.
Read the full explanation → · in clinical review
About CemdisiranDrug
Administered per the protocol
From the trial registry — its own words, unedited.
What a drug is here: A medicine — a chemical or small-molecule treatment — given as the thing being studied.
Read the full explanation → · in clinical review
Common questions
Answered from this trial’s registry record. Where the record doesn’t say, these answers say so rather than filling the gap.
Am I eligible for this trial?
Only the trial siteTrial siteA hospital or clinic where a study is actually run.Read more → can decide whether someone can take part. Concord cannot make that determination, and neither can any tool that has not examined you.
What the study lists: a minimum age of 18 years.
The full inclusionInclusion criteriaThe things you must have or be for a study to consider you.Read more → and exclusion criteriaExclusion criteriaThe things that would prevent someone from taking part.Read more → are published on this page, exactly as the study team wrote them.
The useful next step is to bring this trial to your doctor. Answering a few questions first gives them something concrete to review.
From the trial registry
- eligibilityModule.minimumAge
- eligibilityModule.eligibilityCriteria
Is there a placebo?
This study does not list a placeboPlaceboA dummy treatment with no active medicine, used for comparison.Read more → group.
From the trial registry
- armsInterventionsModule.armGroups[].type
Would I know which treatment I am getting?
This study is open-labelOpen-labelEveryone knows which treatment is being given — nothing is hidden.Read more →: everyone knows which treatment is being given, including you and the study team.
Groups are assigned by the study team using set rules, rather than by chance.
From the trial registry
- designModule.designInfo.maskingInfo.masking
- designModule.designInfo.allocation
Who can join?
The study lists a minimum age of 18 years, with no upper limit given.
It is open to people of any sex.
It does not accept healthy volunteersHealthy volunteerSomeone without the condition being studied who takes part anyway.Read more →.
Only the trial siteTrial siteA hospital or clinic where a study is actually run.Read more → can confirm whether a particular person can take part.
From the trial registry
- eligibilityModule.minimumAge
- eligibilityModule.sex
- eligibilityModule.healthyVolunteers
How long would this take?
The study's main measurement is taken over: Up to week 108.
The study as a whole is currently expected to finish around 2028-10-10.
How long any one person takes part can differ from the study length. The study team can tell you what the schedule looks like in practice.
From the trial registry
- outcomesModule.primaryOutcomes[].timeFrame
- statusModule.completionDateStruct.date
How many people are taking part?
The study aims to enrol about 202 people.
From the trial registry
- designModule.enrollmentInfo.count
Where is this happening?
This study lists one location: Toronto, Ontario, Canada.
Sites can open and close during a study, so confirm with the team before travelling.
From the trial registry
- trial_locations
About This Trial
This study is researching an experimental treatment combination with two experimental drugs called pozelimab and cemdisiran. The study is focused on people with paroxysmal nocturnal hemoglobinuria (PNH). The aim of this study is to see how safe and effective the pozelimab + cemdisiran combination is for people with PNH in the long term. The pozelimab + cemdisiran combination may be referred to as "study drugs" in this section. This study is looking at several other research questions, including: * How effective is the pozelimab + cemdisiran combination? * What side effects may happen from taking the study drugs? * How much of each study drug is in the blood at different times? * Whether the body makes antibodies against the study drugs (which could make the drugs less effective or could lead to side effects)
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See if this trial could fit youThis page is for informational purposes only and does not constitute medical advice. Clinical trial eligibility can only be determined by the trial site after proper screening. Trial information is sourced from ClinicalTrials.gov and may not reflect the most current status. Always consult your healthcare provider before making decisions about clinical trial participation.