FDA Approves Qfitlia⁢ for Hemophilia A and B Treatment‍ in⁣ Patients 12+

updated March 28, 2025

The U.S. Food and Drug Administration (FDA) has given the green light to Qfitlia (fitusiran) for routine prophylaxis. This treatment aims to prevent or reduce the frequency of⁣ bleeding episodes in patients 12 years and older with hemophilia A or B, regardless of whether they‍ have factor⁤ VIII or IX inhibitors.

Dr. Tanya Wroblewski, deputy director⁣ of the FDA’s Division of Non-Malignant Hematology, highlighted the meaning of this⁣ approval. ‍She noted that Qfitlia offers a less frequent administration schedule compared to existing options, reflecting the⁣ FDA’s commitment to improving⁣ the lives of hemophilia patients.

Hemophilia A and B are genetic disorders stemming from deficiencies in coagulation⁤ factors VIII or ‍IX. These conditions impair⁢ blood clotting,leading to prolonged bleeding⁢ after injuries or surgeries,and potential spontaneous bleeding in muscles,joints,and organs.⁤ Current management involves on-demand or prophylactic treatments using factor VIII or IX products, or factor-mimicking alternatives.

Qfitlia works by reducing antithrombin, a ⁤protein that inhibits blood clotting, thereby increasing thrombin levels, a crucial enzyme in ⁢the clotting process. It is administered subcutaneously, initially once⁣ every two months.Dosing and frequency are adjusted based on the⁤ INNOVANCE Antithrombin companion diagnostic test, ensuring antithrombin activity ⁤stays within the target range to ⁣minimize bleeding and clotting risks. Siemens Healthcare Diagnostics GmbH received FDA clearance for this test.

Two clinical trials involving 177 patients with hemophilia A or B assessed Qfitlia’s efficacy and safety. One study included patients ⁤with ⁣inhibitory antibodies to FVIII or FIX who‍ previously received on-demand ⁢treatment with bypassing⁤ agents. The other involved patients without inhibitors who received on-demand treatment with clotting factor concentrates.Participants initially received a⁢ fixed monthly dose of Qfitlia or their usual on-demand treatment for nine months. The fixed dose ⁢is not approved due to excessive clotting in some patients.

Afterward, patients entered a long-term extension study with adjustable ⁣Qfitlia doses based on antithrombin activity. The efficacy of this antithrombin-based dosing regimen was established by comparing patients on⁢ this regimen during the extension study to the on-demand control data from the initial trials.

The ⁢primary efficacy measure was the annualized bleeding rate. Patients with inhibitors receiving the antithrombin-based dosing regimen of Qfitlia experienced a 73% reduction in estimated ⁣annualized bleeding rate compared to those receiving on-demand bypassing agents. Patients without inhibitors saw⁣ a 71% reduction compared to those receiving on-demand clotting factor concentrates.

Qfitlia⁣ carries a boxed warning for thrombotic events and gallbladder disease, perhaps requiring gallbladder ‍removal.⁣ It also warns⁤ of liver toxicity, necessitating monthly ‍liver blood tests for at least six months after treatment⁣ initiation or dose increases.

Common side effects ⁢include viral infection, nasopharyngitis, and bacterial⁢ infection.

The FDA granted Qfitlia ‍Orphan Drug and Fast Track designations.⁤ Sanofi holds the approval for Qfitlia.

What’s next

Further studies and post-market surveillance⁢ will continue to monitor the long-term safety and effectiveness of Qfitlia in ⁢a broader patient population, providing more data on its impact on managing hemophilia A and B.