Phase 3 Haemophilia Trial, Recruiting

Written by an AI model from ClinicalTrials.gov eligibility criteria and checked on a sample basis. Please confirm against the original criteria.

Who might be able to join this trial:

• Participants must be male and meet a minimum weight requirement for their age group.
• Teenagers aged 12 to 17 must weigh at least 25 kg (about 55 lbs) at the time of signing up.
• Children aged 6 to 11 must weigh at least 19 kg (about 42 lbs) at the time of signing up.
• The minimum weight for children aged 1 to 5 has not yet been set (confirm with trial site).
• Participants must have been diagnosed with severe hemophilia A, or moderately severe to severe hemophilia B.
• Participants must have at least one year of diary entries or medical records showing their bleeding episodes and treatments in the 12 months before signing up.

For participants WITHOUT inhibitors (antibodies that block clotting factor treatments), you must also:

• Have no current inhibitors and no history of inhibitors in the past 5 years.
• Have received clotting factor replacement treatment on at least 50 separate occasions.
• Have followed a regular preventive treatment schedule at least 80% of the time for the past 12 months.

For participants WITH inhibitors, you must also:

• Have a currently documented inhibitor at either a high or low level that makes standard clotting factor treatment ineffective (confirm with trial site).
• Participants who previously had high-level inhibitors but don't currently meet the exact measurement criteria may be considered individually after discussion with the study medical team.
• Hemophilia A participants must have had at least 12 bleeding episodes in the past 12 months requiring bypass treatment; hemophilia B participants must have had at least 8 such episodes.
• Must have been using bypass treatment only when needed (not as routine prevention) during the past 12 months.

Who may not be able to join:

• People with known heart disease, blood clot disorders, or certain inherited or acquired conditions that affect blood clotting, such as Factor V Leiden or antiphospholipid syndrome.
• People who are planning to have surgery during the time the study will be running.
• People who have a bleeding disorder other than hemophilia A or B.
• People with abnormal blood, kidney, or liver test results at the screening stage.
• People with other serious physical or mental health conditions that could make participation risky or affect the study results, in the opinion of the study doctor.
• People who are known to be allergic to hamster protein or any other ingredient in the study treatment.
• People currently using routine preventive treatment with bypass agents, or certain non-factor therapies such as emicizumab, or anyone who has previously received gene therapy for hemophilia.
• People with inhibitors who are on a routine preventive bypass treatment plan, or who have previously used certain non-factor hemophilia therapies (such as fitusiran, concizumab, or emicizumab), may be considered on a case-by-case basis only (confirm with trial site).
• People who regularly use immune-modifying medications such as IVIG, long-term steroids, or rituximab.
• People using certain blood-clot-dissolving medications, blood-thinning medications, or certain anti-inflammatory painkillers within 5 days before the first dose or during the study.
• People who are currently using or planning to use immune tolerance therapy, or routine preventive clotting factor replacement, once the study treatment has started.
• People who have taken part in another clinical trial involving an experimental drug or vaccine within the past 30 days (or longer, depending on local rules) or within 5 half-lives of the other drug before joining.
• People who have previously received the study drug, marstacimab, in another clinical trial.
• People who are HIV-positive with a CD4 cell count of 200 or below (a measure of immune system health).
• People with a significant abnormal heart rhythm or ECG result that could affect their safety or the study results.
• Staff members working directly on this study, their family members, or employees of the study sponsor directly involved in running the study and their family members.

Important: Always verify eligibility with the trial site directly before applying.