Switching from Emicizumab to Marstacimab in Severe Hemophilia A

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This study aims to evaluate the safety and pharmacokinetics of marstacimab in patients with severe hemophilia A who have been on emicizumab for at least six months. It involves a non-randomized, open-label design with approximately 10-15 participants aged 12 to less than 75 years. After a 14-day wash-out period from emicizumab, participants will receive marstacimab for four months while continuing their standard care for breakthrough bleeds. The study will assess adverse events and measure how the body processes the new medication.

Why it matters

Who can join: the full rules

Inclusion Criteria:

1. Male and 12 to \<75 years of age with a minimum body weight of 35 kg at the time of signing the informed consent.
2. Diagnosis of severe hemophilia A (FVIII activity \<1%) without inhibitors.
3. On emicizumab therapy at a standard clinical dose for ≥6 months.

Exclusion Criteria:

1. Previous or current treatment for or history of coronary artery diseases, venous or arterial thrombosis, or ischemic disease.
2. Any medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study.
3. Known hemostatic defect other than hemophilia A.
4. Current use of any prohibited concomitant medication(s) or unwillingness or inability to use a required concomitant medication(s).
5. Previous administration of an investigational product (drug or vaccine) within 30 days or 5 half-lives preceding the first dose of study intervention used in this study (whichever is longer). Participation in studies of other investigational products (drug or vaccine) at any time during participation in this study.
6. Platelet count \<100,000/μl or hemoglobin \<10 g/dL.
7. Clinically significant renal or hepatic function abnormality based on laboratory results at screening, or known kidney or liver disease.
8. CD4 cell count ≤200/μl if HIV positive.
9. Screening 12-lead ECG that demonstrates clinically significant abnormalities that, in the opinion of the investigator, may affect participant safety or interpretation of study results.
10. Known planned surgical procedure.
11. Hypersensitivity or allergic reaction to hamster protein or other components of the study intervention.
12. Investigator site staff directly involved in the conduct of the study and their family members, site staff otherwise supervised by the investigator, and sponsor and sponsor-delegate employees directly involved in the conduct of the study and their family members.

Where it's running

• Orthopaedic Institute for Children/Orthopaedic Hemophilia Treatment Center
  Los Angeles, California, United States Recruiting
• Brody School of Medicine at East Carolina University
  Greenville, North Carolina, United States Recruiting
• ECU Health Medical Center
  Greenville, North Carolina, United States Recruiting
• Nirmal Hospital Pvt Ltd.
  Surat, Gujarat, India Recruiting
• K J Somaiya Hospital & Research Centre
  Mumbai, Maharashtra, India Recruiting
• Ege University Faculty of Medicine Dean's Office
  Bornova, İzmir, Turkey (Türkiye) Recruiting

Study contacts

• Study coordinator: Pfizer CT.gov Call Center
• Email: ClinicalTrials.gov_Inquiries@pfizer.com
• Phone: 1-800-718-1021

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Using Nuwiq to manage bleeding in hemophilia A patients during major surgery

  This study is testing if Nuwiq can help prevent bleeding during major surgery for boys and men over 12 with severe hemophilia A who are already using another treatment called emicizumab.

  Recruiting at 17 sites Phase 4 Octapharma · Dallas, Texas and 17 other locations · NCT05935358

• Understanding antibody changes in hemophilia A patients treated with emicizumab

  This study looks at how the immune system reacts to emicizumab treatment in people with severe hemophilia A by checking leftover samples from their regular doctor visits.

  Recruiting Goethe University · Frankfurt am Main, Hesse · NCT05802836

• Marstacimab for mild to moderate hemophilia A or B in people without inhibitors

  This study tests whether weekly injections of marstacimab can reduce bleeding in adolescents and adults with mild to moderate hemophilia A or B who don’t have inhibitors.

  Recruiting Phase 3 Pfizer · Flowood, Mississippi · NCT07923981

• NXT007 versus emicizumab to prevent bleeds in people with Hemophilia A

  This will test whether NXT007 prevents bleeding better than emicizumab in people aged 12 and older with Hemophilia A, including those with or without factor VIII inhibitors.

  Recruiting at 63 sites Phase 3 Hoffmann-La Roche · Orange, California and 62 other locations · NCT07416604

• Emicizumab prophylaxis for people with Type 3 von Willebrand disease

  This trial will test whether regular emicizumab injections reduce bleeds compared with on-demand standard therapy for people aged 1 month and older with Type 3 von Willebrand disease, while also studying people already on prophylaxis using their prior data.

  Recruiting at 29 sites Phase 3 Hoffmann-La Roche · Sacramento, California and 28 other locations · NCT06998524

• Marstacimab experiences in adolescents and adults with hemophilia

  This registry will collect experiences from adolescents and adults with hemophilia who are receiving marstacimab to see if they prefer subcutaneous injections and to track treatment burden and bleeding rates.

  Recruiting at 2 sites Institute of Hematology & Blood Diseases Hospital, China · Xiamen, Fujian and 1 other locations · NCT06992076

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.