WEDNESDAY, April 2, 2025 (HealthDay News) -- The U.S. Food and Drug Administration has approved Qfitlia (fitusiran) for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients 12 years of age and older with hemophilia A or hemophilia B, with or without factor VIII or IX inhibitors (neutralizing antibodies).

Subcutaneous Qfitlia does not replace the missing coagulation factor VIII or IX, but reduces the amount of the protein antithrombin, leading to an increase in thrombin, an enzyme critical for blood clotting. Dosing starts at once every two months and is based on the FDA-cleared INNOVANCE Antithrombin companion diagnostic test (Siemens). Fixed dosing of Qfitlia is not approved due to excessive clotting risk. Qfitlia has a boxed warning for thrombotic events and gallbladder disease. The most common side effects reported were viral infection, nasopharyngitis, and bacterial infection.

The approval is based on two randomized clinical trials that enrolled 177 adult and pediatric male patients with either hemophilia A or hemophilia B. Among participants with inhibitors who received the antithrombin-based dosing regimen of Qfitlia, there was a 73 percent reduction in the estimated annualized bleeding rate compared with that seen in those who received on-demand treatment with bypassing agents. Among participants without inhibitors receiving the antithrombin-based dosing regimen of Qfitlia, there was a 71 percent reduction in the estimated annualized bleeding rate versus that seen in those who received on-demand treatment with clotting factor concentrates.

"Today's approval of Qfitlia is significant for patients with hemophilia because it can be administered less frequently than other existing options," Tanya Wroblewski, M.D., deputy director of the Division of Non-Malignant Hematology in the FDA Center for Drug Evaluation and Research, said in a statement.

The approval of Qfitlia was granted to Sanofi.

More Information