Factor I Deficiency

Factor I deficiency is a collective term for three rare inherited fibrinogen deficiencies: afibroginenemia, hypofibrinogenemia and dysfibrinogenemia.

• Afibrinogenemia occurs when fibrinogen is missing from the blood altogether.
• Hypofibrinogenemia occurs when fibrinogen is present in only very low levels in the blood.
• Dysfibrinogenemia occurs when fibrinogen is present in normal quantities but defective.

About 1 to 2 people out of 1 million will have factor I deficiency. It is inherited and, unlike hemophilia, is equally likely to affect men and women.

Afibrinogenemia and hypofibrinogenemia are usually diagnosed in newborns who can present with head bleeds, bleeding after circumcision and bleeding from the site of the umbilical cord. Easy bruising, nose and mouth bleeds and soft tissue bleeds are also common. Joint bleeding is relatively uncommon. Women with afibrinogenemia have an increased risk of spontaneous abortion. People with dysfibrinogenemia may have a disposition to thrombosis.

Diagnosis is made by measuring the amount of fibrinogen in the blood, prothrombin time (PT) test, activated partial thromboplastin time (aPTT) test and thrombin clotting time (TCT) test.

Treatment

RiaSTAP^® (fibrinogen concentrate [human]) is now available in the United States for the treatment of factor I deficiency. RiaSTAP is not indicated for dysfibrinogenemia. Fresh frozen plasma may also be given, but cryoprecipitate is used more often to avoid volume overload. In addition, there are three fibrinogen concentrates being used in Europe and Japan. However, there have been some reports of adverse reactions with use of these concentrates.

Learn more about RiaSTAP

Important Safety Information About RiaSTAP

RiaSTAP is indicated for the treatment of acute bleeding episodes in patients with congenital fibrinogen deficiency, including afibrinogenemia and hypofibrinogenemia. RiaSTAP is not indicated for dysfibrinogenemia.

RiaSTAP was approved using maximum clot firmness (MCF) as a surrogate marker likely to predict clinical benefit. Thus, the hemostatic efficacy of RiaSTAP^™ in acute bleeding episodes has not been established. A post-marketing study is being conducted to verify clinical endpoints.

RiaSTAP is contraindicated in individuals who have manifested severe immediate hypersensitivity reactions, including anaphylaxis to RiaSTAP or its components.

Monitor patients for early signs of allergic or hypersensitivity reactions and if necessary, discontinue administration and institute appropriate treatment. Thrombotic events have been reported in patients receiving RiaSTAP; weigh the benefits of administration versus the risks of thrombosis.

RiaSTAP is made from pooled human plasma. Products made from human plasma may contain infectious agents, e.g., viruses and, theoretically, the Creutzfeldt-Jakob disease (CJD) agent.

The most serious adverse reactions that have been reported in subjects in clinical studies who received RiaSTAP are thromboembolic episodes, including myocardial infarction and pulmonary embolism, and allergic-anaphylactic reactions. The most common adverse reactions observed are allergic reactions, including chills, fever, nausea, and vomiting. Monitor patients for early signs of allergic or hypersensitivity reactions and if necessary, discontinue administration.

Please see full prescribing information for RiaSTAP.

RiaSTAP is a trademark of CSL Behring GmbH

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