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Recruiting Phase 3 NCT05744921

NCT05744921 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

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Clinical Trial Summary
NCT ID NCT05744921
Status Recruiting
Phase Phase 3
Sponsor Regeneron Pharmaceuticals
Condition Paroxysmal Nocturnal Hemoglobinuria
Study Type INTERVENTIONAL
Enrollment 202 participants
Start Date 2023-03-07
Primary Completion 2028-10-10

Eligibility & Interventions

Sex All sexes
Min Age 18 Years
Max Age N/A
Study Type INTERVENTIONAL
Interventions
PozelimabCemdisiran

Eligibility Fast-Check

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What to Expect as a Participant

You will actively receive the study intervention — which may be a drug, biologic, device, or procedure.

Phase 3 trials are large pivotal studies comparing the treatment to current standard of care or placebo. Your participation directly contributes to the evidence needed for regulatory approval.

This trial targets 202 participants in total. It began in 2023-03-07 with a primary completion date of 2028-10-10.

⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.

Brief Summary

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)

Eligibility Criteria

Key Inclusion Criteria: Patients Entering from the Parent Study 1. Patients with PNH who have completed, without permanent discontinuation, study treatment in the parent study (R3918-PNH-2021\[NCT05133531\]), including the post-Open-label treatment period (OLTP) transition period, if applicable. 2. Willing and able to comply with clinic visits and study-related procedures, including meningococcal vaccinations required per protocol. Patients Entering with C5 polymorphism 1. 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 2. Diagnosis of PNH confirmed by high-sensitivity flow cytometry testing with PNH granulocytes or monocytes 3. Active disease, as defined by the presence of 1 or more PNH-related sign or symptom as described in the protocol 4. LDH level ≥2 × upper limit of normal (ULN) at the screening visit 5. Willing and able to comply with clinic visits and study-related procedures, including meningococcal vaccinations required per protocol Key Exclusion Criteria: Patients Entering from the Parent Study 1. Significant protocol deviation(s) in the parent study based on the investigator's judgment and to the extent that these would (if continued) impact the study objectives and/or safety of the patient 2. Any new condition or worsening of an existing condition which, in the opinion of the investigator, would make the patient unsuitable for enrollment or could interfere with the patient participating in or completing the study Patients Entering with C5 polymorphism 1. 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 2. Receipt of an organ transplant, history of bone marrow transplantation or other hematologic transplant 3. 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 4. Positive hepatitis B surface antigen or hepatitis C virus Ribonucleic acid (RNA) during screening 5. Patients with known HIV with history of opportunistic infections in the last 1 year as described in the protocol 6. Known hereditary complement deficiency 7. Documented history of active, uncontrolled, ongoing systemic autoimmune diseases 8. 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 Inclusion/ Exclusion Criteria apply

Contact & Investigator

Central Contact

Clinical Trials Administrator

✉ clinicaltrials@regeneron.com

📞 844-734-6643

Principal Investigator

Clinical Trial Management

STUDY DIRECTOR

Regeneron Pharmaceuticals

Frequently Asked Questions

Who can join the NCT05744921 clinical trial?

This trial is open to participants of all sexes, aged 18 Years or older, studying Paroxysmal Nocturnal Hemoglobinuria. Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.

What phase is the NCT05744921 trial and what does that mean for participants?

Phase 3 trials are large-scale studies comparing the new treatment to existing standards of care or a placebo. They provide the evidence needed for regulatory approval. This trial targets 202 participants.

Is NCT05744921 currently recruiting?

Yes, NCT05744921 is actively recruiting participants. Contact the research team at clinicaltrials@regeneron.com for enrollment information.

Where is the NCT05744921 trial being conducted?

This trial is being conducted at Toronto, Canada, Medellín, Colombia, Budapest, Hungary, Kochi, India and 11 additional locations.

Who is sponsoring the NCT05744921 clinical trial?

NCT05744921 is sponsored by Regeneron Pharmaceuticals. The principal investigator is Clinical Trial Management at Regeneron Pharmaceuticals. The trial plans to enroll 202 participants.

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ClinicalMetric — Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here — always consult a qualified healthcare professional. Full Disclaimer  ·  Last Reviewed: September 2026  ·  Data Methodology