Switching from Emicizumab to Marstacimab in Severe Hemophilia A

A PHASE 1B OPEN-LABEL NON-RANDOMIZED STUDY TO ASSESS THE SAFETY, PHARMACOKINETICS, AND PHARMACODYNAMICS OF MARSTACIMAB TREATMENT FOLLOWING THE DISCONTINUATION OF EMICIZUMAB THERAPY IN ADOLESCENT AND ADULT PARTICIPANTS WITH SEVERE HEMOPHILIA A WITHOUT INHIBITORS.

This study is testing if switching from emicizumab to marstacimab is safe and how well the body handles the new medication in people with severe hemophilia A.

Quick facts

• Phase: Phase 1
• Study type: Interventional
• Enrollment: 15 (estimated)
• Ages: 12 Years to 74 Years
• Sex: Male
• Sponsor: Pfizer (Industry-sponsored)
• Drugs / interventions: emicizumab, marstacimab
• Locations: 4 sites (Los Angeles, California and 3 other locations)
• Trial ID: NCT06703606 on ClinicalTrials.gov

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.

Who should consider this trial

Good fit: Ideal candidates are males aged 12 to less than 75 years with severe hemophilia A who have been on emicizumab therapy for at least six months.

Not a fit: Patients with other hemostatic defects or those with a history of certain cardiovascular conditions may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a new treatment option for patients with severe hemophilia A, potentially improving their bleeding management.

How similar studies have performed: While this approach is novel in the context of switching therapies for severe hemophilia A, similar studies have shown promise in evaluating new treatments for bleeding disorders.

Eligibility criteria

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 this trial is running

Los Angeles, California and 3 other locations

• Orthopaedic Institute for Children/Orthopaedic Hemophilia Treatment Center — Los Angeles, California, 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

Conditions Severe Hemophilia A; Hemophilia A; Severe Hemophilia A Without Inhibitors