Understanding hemophilia
Explore the world of hemophilia and approaches to treatment.
What is hemophilia?
Hemophilia is a rare, genetic disease that affects the body’s ability to properly form blood clots.
In our bodies, clots are formed through a cascade of proteins. These proteins, known as clotting factors, work together to help blood clot properly and stop bleeding.
In hemophilia, at least one of these factors is missing or at levels too low to be effective at forming a clot and stopping a bleed. People with hemophilia A have low levels of factor VIII. People with hemophilia B have low levels of factor IX.
In the United States, as many as 33,000 males live with hemophilia
Soucie JM, et al. Hemophilia. 2020.
76% hemophilia A
(factor VIII deficiency)
24% hemophilia B
(factor IX deficiency)
.
Soucie JM, et al. Hemophilia. 2020.
How does someone get hemophilia?
Hemophilia is a recessive trait, generally inherited at birth through the X chromosome. In rare cases, females can have two altered X chromosomes, while males can have hemophilia with only a single altered X chromosome.
Because of this, the majority of cases (~79%) are present in males. Females with only one altered X are considered carriers, but can experience hemophilia symptoms as well.
Inheritance from female carrier:
Inheritance from male with hemophilia:
How severities determine treatment options
A hemophilia diagnosis can range from mild to moderate to severe based on someone’s baseline factor level.
A factor levels test should be administered to determine hemophilia severity, anticipate symptoms, and guide treatment.
Treatment options include:
- On-demand therapy
Taken as needed after bleeding starts - Prophylactic therapy
Taken routinely to prevent bleeds - Gene therapy
One-time infusion to prevent bleeds
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Treatment considerations for inhibitors
Another consideration is factor inhibitors, which are antibodies to factor that some people may develop. These inhibitors cause further complications around clotting and the ability to treat with factor replacement.
Always consult a doctor about your own individual condition and what treatments are best for you.
If someone has 4% of clotting factor VIII activity, what’s their diagnosis?
Low factor VIII is associated with hemophilia A, and 4% clotting activity would be considered moderate.
Current treatments
Hemophilia requires lifelong care but thanks to the success of modern treatments, people with hemophilia are able to live longer, healthier lives. Therapy options available today improve factor levels, prevent excessive bleeding, and may reduce the risk of long-term joint health concerns.
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Evolving care
Alternate treatment approaches currently being studied may be able to help address some additional needs in hemophilia, such as administration frequency, inhibitor risk, and modes of delivery.
Significant progress has been made in the past decade; gene therapy and mimetic options have recently been approved in the US, and rebalancing research continues to advance through clinical trials.
Gene therapy for hemophilia is a one-time infusion for adult males that may offer long-term bleed protection. For some people, it may allow them to stop routine prophylaxis treatment...
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Gene therapy for hemophilia is a one-time infusion for adult males that may offer long-term bleed protection. For some people, it may allow them to stop routine prophylaxis treatment.
There are gene therapy options that can be used to treat either hemophilia A or B, where a functioning gene informs the body to produce either factor VIII or factor IX, respectively.
It’s important to talk to your doctor about gene therapy, as it may not be appropriate for all people with hemophilia.
Rebalancing is an investigational approach to restoring hemostasis, or limiting blood loss, by reducing anticoagulants. Anticoagulants promote blood flow.........
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Rebalancing is an investigational approach to restoring hemostasis, or limiting blood loss, by reducing anticoagulants. Anticoagulants promote blood flow.
There is an imbalance in favor of bleeding when either factor VIII or factor IX is limited. Rebalancing aims to inhibit certain anticoagulants to improve clotting function.
One anticoagulant being evaluated in clinical trials is tissue factor pathway inhibitor (TFPI) because it limits clotting activity at an early stage in the clotting process.
Rebalancing through TFPI inhibition is being explored for people with hemophilia A and B, and for those with and without inhibitors.
Hemophilia challenges
At times, symptoms of hemophilia might feel “invisible” and hidden under the surface. Whether they’re minor or chronic, obvious or unseen, occasional or every day—these burdens go beyond just bleeds and should be acknowledged by and addressed with your doctor.
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Life disruptions
1 out of 3 people with hemophilia find storing, preparing, and mixing prophylaxis disruptive to their daily routine.
Adherence issues
About 1 out of 2 people with hemophilia experience worry over treatment issues. The potential negative impact of stress could result in poor adherence.
Venous access
A year-long, multicenter study in France found that 37% of people with hemophilia experienced venous access difficulty. Even in the general population, venous access can become challenging in later years.
Joint pain
For those with severe hemophilia, too many bleeds can lead to joint damage, and over time, mobility loss. Even young adults may experience hemophilic arthropathy.
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Pfizer has been committed to innovation in hemophilia for over 25 years
Pfizer has a long history of supporting the hemophilia community, and we remain committed to innovation and continued research. While significant progress has been made, we believe even more can be done to improve treatment.