ClinicalTrials.gov record NCT07154745

A Study to Evaluate How Pozelimab + Cemdisiran Combination Therapy Works in Adult Patients With Paroxysmal Nocturnal Hemoglobinuria (PNH) Whose Current Treatment is Not Working Efficiently

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Jul 27, 2026

A Single Arm Study to Evaluate the Efficacy and Safety of Pozelimab and Cemdisiran Combination Therapy in Patients With Paroxysmal Nocturnal Hemoglobinuria With Inadequate Control of Intravascular Hemolysis on Currently Available C5 Inhibitor Therapy

StatusRecruitingThe study is currently enrolling participants. Only the study team can say whether a particular person can join.
Study typeInterventionalA study in which researchers assign participants to one or more interventions, such as a drug, procedure, device, behavioural programme or other approach, to measure their effects.
PhasePhase 3A later-stage study, usually with more participants, designed to give stronger evidence about how well a treatment works and how safe it is. It often compares the treatment with standard care or a placebo, and results may support an application for approval.
Age18 years old and older
SexAll
LocationBrazil, Canada, Italy, Poland, South Korea, Spain, Turkey
AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This Phase 3, single‑arm study gives all participants the combination of two experimental drugs, pozelimab and cemdisiran, to evaluate their effect on hemolysis in PNH. It is aimed at adults whose PNH remains inadequately controlled despite treatment with a marketed C5 inhibitor (eculizumab, ravulizumab, or crovalimab). The main treatment period is 28 weeks with a 52‑week extension, and the study measures blood markers of hemolysis (LDH), safety, drug levels, and immune responses. Key eligibility gates include being an adult with PNH on a labeled C5 inhibitor for at least 6 months and persistently elevated LDH; meningococcal vaccination and some medical exclusions apply.

What it is studying. The study tests whether giving pozelimab plus cemdisiran to adults with PNH whose disease is inadequately controlled on current C5 inhibitor therapy (for example, persistently elevated LDH) changes intravascular hemolysis (measured by LDH). It also measures safety events, drug concentrations, total C5, complement activity, and whether participants develop antibodies to the study drugs.

What the researchers hope to learn. To measure change in LDH (hemolysis) from baseline; to assess LDH normalization and control (LDH ≤1.5×ULN); to evaluate transfusion avoidance and hemoglobin outcomes; to assess fatigue scores, safety and severity of adverse events; and to measure drug levels, total C5, complement activity, and anti‑drug antibody incidence and magnitude.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

This study is researching a treatment combination with two experimental drugs called pozelimab and cemdisiran referred to as "study drugs". Researchers are looking for a better way to treat Paroxysmal Nocturnal Hemoglobinuria (PNH). The aim of the study is to see how well the pozelimab and cemdisiran combination works to lower hemolysis in participants whose PNH has been not well controlled even after taking other complement component 5 (C5) inhibitors, eculizumab/eculizumab biosimilar, ravulizumab or crovalimab. The study is looking at several other research questions, including:

  • What side effects may happen from taking the study drugs?
  • How much of the study drugs are in the blood at different times?
  • Whether the body makes antibodies against the study drug (which could make the study drugs not work as well or could lead to side effects)

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Drug
  • Pozelimab
  • Cemdisiran

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

  • Diagnosis of PNH confirmed by a history of high-sensitivity flow cytometry from prior testing
  • Currently treated with marketed eculizumab, ravulizumab, or crovalimab at the labeled dose for at least 6 months
  • LDH persistently > 1.5 × Upper Limit of Normal (ULN) in the previous 6 months that the Principal Investigator (PI) attributes is due to intravascular hemolysis
  • At least 2 screening LDH values from different visits as described in the protocol
  • Willing and able to comply with clinic/remote visits and study-related procedures, including completion of the full series of meningococcal vaccinations required per protocol and agreement to continue to remain up to date with these vaccinations during the study
  • Key

Exclusion criteria

  • Receipt of an organ transplant, history of bone marrow transplantation or other hematologic transplants
  • Body weight <40 kilograms at screening visit
  • Patients with a known or suspected C5 mutation that is refractory to their current C5i treatment as described in the protocol
  • Any active or ongoing infection within 2 weeks of screening or during the screening period or any recent infection as described in the protocol
  • Known hereditary complement deficiency
  • Note: Other protocol-defined Inclusion/ Exclusion Criteria apply

Study description and what participation involves

The study's detailed description, as published on ClinicalTrials.gov.

Detailed description from the registry

The treatment period has two parts, a Treatment Period (TP, 28 weeks) and an Extension treatment Period (EP, 52 weeks).

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

Participants will receive the study drugs pozelimab and cemdisiran per the study schedule during a 28-week Treatment Period followed by a 52-week Extension Period. They will attend clinic or remote visits for blood tests (including LDH and drug/antibody measurements), safety monitoring, and complete fatigue questionnaires. Participants must complete and stay up to date with the required meningococcal vaccinations. The study team will monitor for side effects and collect data on hemoglobin levels and transfusion needs as defined in the protocol.

How the study is structured. Interventional, Phase 3, single‑group study with no masking: every enrolled participant receives both pozelimab and cemdisiran. There is a 28‑week treatment period followed by a 52‑week extension; outcomes are measured over these periods. There is no randomized control or placebo arm.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

  • The listed sites are in Brazil, Canada, Italy, Poland, South Korea, Spain, Turkey. Is any of them reachable for me, and does the study help with travel?
  • Which of the eligibility criteria would need to be checked with tests before I could join?

More on paroxysmal nocturnal hemoglobinuria

Clinical trials44 trials listed for paroxysmal nocturnal hemoglobinuriaEvery trial the registry lists for paroxysmal nocturnal hemoglobinuria, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in paroxysmal nocturnal hemoglobinuria researchLatest monthly update: September 2026. Includes: Treatment access. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start
Jun 11, 2026
Primary completion
Jan 18, 2030 (estimated)
Study completion
Dec 4, 2031 (estimated)
Target enrollment
35 participants (estimated)
Last updated on registry
Aug 5, 2026
Data verified
Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor
Regeneron Pharmaceuticals

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Participating sites (20)

  • Hospital das Clinicas da FMRP USPRecruiting

    Ribeirão Preto, São Paulo, 14051-260 · Brazil

  • Faculdade de Medicina do ABCRecruiting

    Santo André, São Paulo, 09060 870 · Brazil

  • Hospital Santa MarcelinaRecruiting

    São Paulo, 08270-070 · Brazil

  • CISSS-CARecruiting

    Lévis, Quebec, G6V 3Z1 · Canada

  • Universita Cattolica del Sacro Cuore - Policlinico Universitario A. GemelliRecruiting

    Rome, Lazio, 00168 · Italy

  • AOU CareggiRecruiting

    Florence, Tuscany, 50134 · Italy

  • SC Hematology, AOU Città della Salute e della Scienza di TorinoRecruiting

    Torino, 10126 · Italy

  • In-Vivo Sp. z o.o.Recruiting

    Bydgoszcz, Kuyavian-Pomeranian Voivodeship, 85-048 · Poland

  • Seoul National University HospitalRecruiting

    Seoul, 03080 · South Korea

  • Severance HospitalRecruiting

    Seoul, 03722 · South Korea

Terms used on this page · explanations by MedicalUpdates.ai

study drug
A treatment that is being tested and has not been approved for this use. It may be approved for a different condition. Being studied does not mean it works or is available outside the study.
Upper Limit of Normal
The highest value of a blood test that a laboratory considers normal. Criteria such as '≤ 3 × ULN' mean the result must be no more than three times that value.
Principal Investigator
The doctor or scientist responsible for running the study at a site or overall.
at screening
The checks done before enrolment to see whether a person qualifies, such as tests, scans or a review of medical history.
refractory
A condition that has not responded to a treatment. 'Relapsed' means it responded and then came back; 'refractory' means it did not respond in the first place.
Exclusion Criteria
The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.
Key Inclusion Criteria
The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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