Sanjay Ahuja, MD, Pediatric Hematologist, Chief Medical and Informatics Officer at Innovative Hematology and the Indiana Hemophilia and Thrombosis Center (IHTC), discusses the U.S. Food and Drug Administration (FDA) approval of Qfitlia (fitusiran) for patients with hemophilia A or B.
Hemophilia is a rare bleeding disorder that slows the blood clotting process. People with this disorder experience prolonged bleeding following an injury or surgery. In severe cases, heavy bleeding occurs after minor trauma or in the absence of injury. Serious complications can result from bleeding into the joints, muscles, brain, or other internal organs. The major types of this disorder are hemophilia A and hemophilia B, caused by a deficiency of factor VIII and IX, respectively.
Fitusiran is the first antithrombin lowering therapy approved by the FDA for treatment of patients ages 12 years and older with hemophilia A and B, with or without factor VII or IX inhibitors. Fitusiran is a small interference RNA drug that inhibits antithrombin and promotes thrombin generation, restoring homeostasis and increasing blood clotting. It is administered subcutaneously with a 50mg dose.
ATLAS Clinical Trial Program
The approval is based on data from the ATLAS phase 3 studies that evaluated the safety and efficacy of fitusiran in patients with hemophilia A and B. Key results included a 71% bleed reduction in annualized bleed rate (ABR) for patients without inhibitors treated with fitusiran compared to clotting factor concentrate on-demand and a 73% reduction in ABR compared to bypassing agent on-demand for patients with inhibitors. The median ABR during the open-label extension study was 3.8 in patients without inhibitors and 1.9 in patients with inhibitors. Median annualized spontaneous bleeding rate during the open-label extension was 1.9 in patients with and without inhibitors. Additionally, about half of the patients in the open-label extension experienced one or fewer bleeds.
Potential for significant adverse events, such as thrombotic events, acute and recurrent gallbladder disease, and hepatotoxicity, was observed. The most common adverse events were viral infection, nasopharyngitis, and bacterial infection.
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To learn more about hemophilia and other rare hematologic conditions, visit https://checkrare.com/diseases/hematologic-disorders/