Marstacimab for Hemophilia A

Overseen By Pfizer CT.gov Call Center

Age: Any Age

Sex: Male

Trial Phase: Phase 1

Sponsor: Pfizer

Must be taking: Emicizumab

Disqualifiers: Coronary artery disease, Thrombosis, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

Duration: 16 weeks

15 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new medicine called marstacimab for individuals with severe hemophilia A, a condition where blood doesn't clot normally, leading to excessive bleeding. The study aims to assess the safety of marstacimab, how the body processes it, and its effectiveness in patients. Participants should have severe hemophilia A without inhibitors and should have been on emicizumab (a preventive treatment) for at least six months. Eligible participants will receive weekly injections of marstacimab for four months. The goal is to help doctors understand how marstacimab can be used in real-world settings for patients seeking to switch treatments. As a Phase 1 trial, this research focuses on understanding how marstacimab works in people, offering participants the opportunity to be among the first to receive this new treatment.

Do I need to stop my current medications to join the trial?

You will need to stop taking emicizumab at least 14 days before starting marstacimab. However, you can continue using your usual treatment for bleeding during the study.

Is there any evidence suggesting that marstacimab is likely to be safe for humans?

Previous studies have generally shown that patients tolerate marstacimab well. Research indicates there were no deaths or cases of blood clots reported. Common side effects were mild, including reactions at the injection site. The safety profile from various studies suggests that marstacimab is safe for people with hemophilia A, as it did not cause serious harm to those who used it. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising?

Unlike the standard treatments for Hemophilia A, which often involve intravenous infusions of clotting factors, Marstacimab offers a new approach. This drug is administered subcutaneously, meaning it can be delivered under the skin like an insulin shot, which is generally easier and less invasive than intravenous methods. Marstacimab works by targeting tissue factor pathway inhibitor (TFPI), a mechanism different from traditional therapies that replace missing clotting factors. Researchers are excited about Marstacimab because it promises a potentially more convenient treatment option with a novel mechanism that could improve outcomes for people with Hemophilia A.

What evidence suggests that marstacimab might be an effective treatment for hemophilia A?

Research has shown that marstacimab, the investigational treatment in this trial, can help reduce bleeding in people with hemophilia. One study showed that marstacimab lowered the yearly bleeding rate by 91.6% compared to treating bleeds only when they occur. It also performed as well as standard preventive treatments. Another study found a 35.2% drop in bleeding episodes, highlighting its potential to control bleeds. These results suggest that marstacimab could significantly help manage hemophilia A by reducing the frequency of bleeds. ^{4 6 7 8 9}

Who Is on the Research Team?

Pfizer CT.gov Call Center

Principal Investigator

Pfizer

Are You a Good Fit for This Trial?

This trial is for males aged 12 to under 75 with severe Hemophilia A, weighing at least 35 kg. They must have been on emicizumab therapy for routine prophylaxis for over 6 months. It's not specified who can't join the trial.

Inclusion Criteria

I am a male, aged 12-74, and weigh at least 35 kg.

I have severe hemophilia A with less than 1% factor VIII activity.

I have been on emicizumab for at least 6 months.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Wash-out

14-day wash-out period following discontinuation of emicizumab

2 weeks

Treatment

Participants receive marstacimab 150 mg subcutaneous injections once weekly for 4 months

16 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Marstacimab

Trial Overview The study tests marstacimab in patients with severe Hemophilia A switching from emicizumab. Participants will receive weekly injections of marstacimab (150 mg) for four months, starting no sooner than two weeks after their last dose of emicizumab.

How Is the Trial Designed?

Group I: MARSTACIMAB Experimental Treatment 1 Intervention

Marstacimab 150 mg subcutaneous (SC) once weekly (QW)

Who Is Running the Clinical Trial?

Pfizer

Lead Sponsor

Trials

4,712

Recruited

50,980,000+

Known For

Vaccine Innovations

Top Products

Viagra, Zoloft, Lipitor, Prevnar 13

Albert Bourla

Pfizer

Chief Executive Officer since 2019

PhD in Biotechnology of Reproduction, Aristotle University of Thessaloniki

Patrizia Cavazzoni

Pfizer

Chief Medical Officer

MD from McGill University

Citations

1. pfizer.com pfizer.com/news/press-release/press-release-detail/pfizer-announces-positive-topline-phase-3-results

Pfizer Announces Positive Topline Phase 3 Results for ... Study demonstrates superiority, showing both statistically significant and clinically meaningful reduction in annualized bleeding rate with ...

2. hematologyadvisor.com hematologyadvisor.com/news/hemophilia-marstacimab-efficacy-inhibitors-treatment-risk/

Marstacimab Shows Efficacy in Hemophilia With Inhibitors In a cohort of 48 participants living with hemophilia with inhibitors, marstacimab reduced annualized bleeding rate by 93% over 12 months ...

3. bleeding.org bleeding.org/news/pfizer-announces-phase-3-trial-results-for-hemophiliainhibitor-therapy

Pfizer Announces Phase 3 Trial Results for Hemophilia ... The topline results showed that marstacimab-hncq achieved a 93% reduction in ABR over 12 months (1.39 ABR with marstacimab-hncq vs 19.78 ABR ...

4. ashpublications.org ashpublications.org/ashclinicalnews/news/8684/Marstacimab-Shows-Long-Term-Efficacy-in-Severe

Marstacimab Shows Long-Term Efficacy in Severe ... The mean ABR for treated bleeds with routine prophylaxis stood at 7.9 during the observation phase, reducing by 35.2% to 5.1 with marstacimab.

5. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC12205756/

Marstacimab for the Treatment of Hemophilia A or B - PMC In Phase 3, marstacimab reduced annualized bleed rates by 91.6% compared with episodic treatment and was non-inferior to factor prophylaxis.

6. ashpublications.org ashpublications.org/blood/article/144/Supplement%201/1210/532115/Safety-Biomarkers-in-Participants-With-Severe

Safety Biomarkers in Participants With Severe Hemophilia A ... The efficacy and safety of marstacimab administration up to 450 mg ... Here, we present safety biomarker data from the BASIS study.

7. pfizer.com pfizer.com/news/press-release/press-release-detail/marstacimab-phase-3-data-presented-ash-2023-demonstrate

Marstacimab Phase 3 Data Presented at ASH 2023 ... The safety profile for marstacimab was consistent with Phase 1/2 results and treatment was generally well-tolerated. No deaths were reported ...

8. ema.europa.eu ema.europa.eu/en/documents/product-information/hympavzi-epar-product-information_en.pdf

Hympavzi, INN-marstacimab - European Medicines Agency Safety data in Table 1 are based on pooled data from the Phase 3 safety and efficacy study (BASIS) and its open-label extension (OLE) study ...

9. accessdata.fda.gov accessdata.fda.gov/drugsatfda_docs/nda/2024/761369Orig1s000IntegratedR.pdf

761369Orig1s000 INTEGRATED REVIEW - accessdata.fda.gov The primary safety profile for marstacimab is based on safety data from the active treatment phase (ATP) of Study B7841005. As per study ...