Making Strides Toward Preventing Inhibitors in Bleeding Disorders

CDC’s Division of Blood Disorders is committed to reducing the occurrence of inhibitors. Find out what they are doing to reach their goal.

Centers for Disease Control and Prevention’s (CDC’s) Division of Blood Disorders (DBD) is committed to reducing the occurrence of inhibitors which are the most significant and costly complication affecting people with bleeding disorders like hemophilia and von Willebrand Disease (VWD).

In March 2012, DBD hosted the first Inhibitor Summit, a national meeting on inhibitors to discuss the urgent need for a system to monitor this serious complication of treatment. This discussion informed efforts by DBD to begin collecting and monitoring information on inhibitor development, treatment, and outcomes by building onto an existing healthcare monitoring system.

Nearly five years later, DBD held the Second Inhibitor Summit on January 30, 2017. This meeting of over 40 key stakeholders and subject matter experts evaluated the current state of patient enrollment in the system and how to improve accuracy and representativeness, discussed how inhibitors are currently being monitored, and generated ideas for how this monitoring system can be better used or improved to prevent inhibitors.

What are inhibitors?

People with hemophilia, and many with VWD type 3, use treatment products called clotting factor concentrates (“factor”). These treatment products improve blood clotting, and they are used to stop or prevent a bleeding episode. When a person develops an inhibitor, the body stops accepting the factor treatment product as a normal part of blood. The body thinks the factor is a foreign substance and tries to destroy it with an inhibitor. The inhibitor keeps the treatment from working, which makes it more difficult to stop a bleeding episode. A person who develops an inhibitor will require special treatment until his or her body stops making inhibitors. Inhibitors most often appear during the first 50 times a person is treated with clotting factor concentrates, but they can appear at any time. In addition, it is estimated that 1 out of every 5 people with hemophilia will develop an inhibitor in their lifetimes.

Why are inhibitors an important area of study for CDC?

Treatment for people with an inhibitor poses special challenges. The healthcare costs associated with inhibitors can be staggering because of the amount and type of treatment product required to stop bleeding. Also, people with hemophilia or VWD who develop an inhibitor are twice as likely to be hospitalized for a bleeding complication, and they are at increased risk of death. CDC is working to reduce the number of people who develop inhibitors, decrease healthcare costs for people with bleeding disorders, and ensure that all treatment products are safe and effective for people with bleeding disorders.

What is the system CDC uses to monitor inhibitors?

The system CDC uses to monitor inhibitors is called the Community Counts Registry for Bleeding Disorders Surveillance. This registry monitors the health of people who receive care at Hemophilia Treatment Centers (HTCs). It is funded by CDC through a cooperative agreement awarded to the American Thrombosis and Hemostasis Network in partnership with the U.S. Hemophilia Treatment Center Network. The program gathers and shares valuable information on a variety of health outcomes, including those related to inhibitors. For example, through the Registry, CDC can establish estimates of the number of participants with new and existing inhibitors, identify unexpected increases in how often inhibitors develop, and identify risks for inhibitor development.

What was the purpose of the Second Inhibitor Summit?

CDC held the meeting to discuss how inhibitors are currently being monitored and how this monitoring system can be better used or improved to prevent inhibitors.

The goals of the meeting were to

• Share information about the Community Counts Registry for Bleeding Disorders Surveillance and the current state of national inhibitor monitoring,
• Identify steps to collect the most accurate and representative national data possible on the occurrence of inhibitors,
• Determine strategies to make sure that inhibitor testing methods are accurate, and
• Explore the need for a national, coordinated inhibitor science agenda.

Who attended the Summit?

Meeting attendees included

• Federal partners: In addition to CDC, representatives from the National Institutes of Health (NIH), the Health Resources and Services Administration (HRSA) and the Food and Drug Administration (FDA) attended,
• Bleeding disorder community partners: National Hemophilia Foundation (NHF), Hemophilia Federation of America (HFA), World Federation of Hemophilia, American Thrombosis and Hemostasis Network,
• Representatives of scientific organizations: NHF’s Medical and Scientific Advisory Committee, Hemostasis and Thrombosis Research Society, International Society of Thrombosis and Haemostasis, and others, and
• Representatives of pharmaceutical companies with an interest: Bayer Healthcare Pharmaceuticals, Grifols, Novo Nordisk, Pfizer, and others.

What’s next?

• CDC is working with partners to develop educational materials for patients and care providers about the importance of regular testing for inhibitors.
• CDC is working with other Federal partners, including the NIH, HRSA, and FDA, to strengthen support for prevention efforts.
• CDC is working with 130 federally supported HTCs located throughout the United States to strengthen the monitoring system for people who receive care at HTCs and to learn more about what causes inhibitors.

What does CDC want people with hemophilia or VWD type 3 to know?

CDC encourages people with hemophilia or VWD type 3 to

• Get tested for inhibitors once a year,
• Take advantage of the free inhibitor testing at federally funded HTCs through the CDC Community Counts Registry for Bleeding Disorders Surveillance program,
• Seek support and learn from other individuals and families who have been affected by inhibitors, and
• Consider participating in research studies that can result in new prevention programs that help reduce medical complications and lead to improved quality of life.