RECRUITING

A Study to Learn About How Changing Therapy From Emicizumab to Marstacimab Affects People With the Severe Hemophilia A.

Conditions

Severe Hemophilia A Hemophilia A Severe Hemophilia A Without Inhibitors

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Study Overview

This clinical trial focuses on testing the efficacy of different digital interventions to promote re-engagement in cancer-related long-term follow-up care for adolescent and young adult (AYA) survivors of childhood cancer.

Description

The purpose of the study is to learn about safety, how the body processes marstacimab and how it works in patients with severe hemophilia A without inhibitors. Hemophilia A is rare bleeding disorder where the blood doesn't clot normally. This causes a person to bleed a lot, even from a small cut. These patients who are on emicizumab medicine for routine prophylaxis for at least 6 months, and desire to switch to marstacimab medicine. Inhibitors are antibodies that the immune system develops because it sees the infused clotting factor as a foreign substance that needs to be destroyed. Antibodies are proteins that eat up the activated factor before it has time to stop the bleeding. Prophylaxis are preventive medicines. This study is seeking for participants: * with severe Hemophilia A withouth inhibitors who are on emicizumab treatment for at least 6 months. * must be 12 to less than 75 years old * must have a body weight of at least 35 kilograms. The results from this study will serve as a guide to doctors and their hemophilia A patients who will change their medicines in the real-world clinical setting. Patients who can take part in the study will receive marstacimab medicine as weekly injections under the skin of 150 milligrams for 4 months. Study treatment with marstacimab will be initiated no earlier than 14 days after last dose of emicizumab. The study can last up to 6 months. The sponsor will provide marstacimab. Patients will continue their usual treatment with the infused clotting factor for their bleeds when taking part in the study. Roll-over into an optional study treatment extension period will be available to participants who wish to continue prophylaxis with marstacimab in countries where it is not commercially available.

Official Title

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.

Quick Facts

Study Start:2025-05-13

Study Completion:2027-05-05

Study Type:Not specified

Phase:Not Applicable

Enrollment:Not specified

Status:RECRUITING

Study ID

NCT06703606

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Ages Eligible for Study:12 Years to 74 Years

Sexes Eligible for Study:MALE

Accepts Healthy Volunteers:No

Standard Ages:CHILD, ADULT, OLDER_ADULT

Inclusion Criteria	Exclusion 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.	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.

Inclusion Criteria

Exclusion 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.

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.

Contacts and Locations

Study Contact

Pfizer CT.gov Call Center

CONTACT

1-800-718-1021

ClinicalTrials.gov_Inquiries@pfizer.com

Principal Investigator

Pfizer CT.gov Call Center

STUDY_DIRECTOR

Pfizer

Study Locations (Sites)

Orthopaedic Institute for Children

Los Angeles, California, 90007

United States

Collaborators and Investigators

Sponsor: Pfizer

Pfizer CT.gov Call Center, STUDY_DIRECTOR, Pfizer

Study Record Dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Registration Dates

Study Start Date2025-05-13

Study Completion Date2027-05-05

Study Record Updates

Study Start Date2025-05-13

Study Completion Date2027-05-05

Terms related to this study

Keywords Provided by Researchers

Hemophilia A
Severe Hemophilia A
Severe Hemophilia A Without Inhibitors

Additional Relevant MeSH Terms

Severe Hemophilia A