Qfitlia: First US-Approved Therapy for Hemophilia A/B with or without Inhibitors

PARIS, France, March 28, 2025 — The United States Food and Drug Administration (FDA) has granted approval for Qfitlia (fitusiran), marking a significant advancement in the treatment of hemophilia. This novel therapy is the first of its kind to lower antithrombin (AT) for routine prophylactic use, aiming to prevent or lessen the occurrence of bleeding episodes in individuals aged 12 and above who suffer from hemophilia A or B, whether or not they have factor VIII or IX inhibitors. The FDA's approval follows encouraging results from the ATLAS phase 3 clinical trials, which illustrated notable bleed protection, measured through annualized bleeding rates (ABR) among patients with hemophilia, irrespective of the presence of inhibitors.

Phil Gattone, President and CEO of the National Bleeding Disorders Foundation, expressed optimism about Qfitlia's potential. He pointed out that current therapies often compel hemophilia patients to balance effective bleed control against convenient dosing schedules, leading to compromises in disease management. Qfitlia introduces a transformative approach to providing protection for people living with hemophilia, simultaneously decreasing the dosing frequency for patients and their families.

The therapeutic mechanism of Qfitlia involves reducing the levels of antithrombin, a protein that impedes blood clotting, which in turn enhances thrombin generation to restore appropriate hemostasis in hemophilia patients. This innovative treatment utilizes small-interfering RNA technology, permitting less frequent treatment sessions, simple subcutaneous administration, and low-volume injections.

Brian Foard, Executive Vice President and Head of Specialty Care at Sanofi, emphasized the importance of the approval in the context of the company's dedication to innovation and improving care for those with rare blood disorders. Qfitlia's introduction could substantially reshape the hemophilia treatment landscape through its effective bleed protection, infrequent dosing, and easy administration. Sanofi's comprehensive portfolio of hemophilia therapies continues to grow as the company strives to offer effective protection with minimized treatment burdens tailored to individual patient needs.

Dr. Guy Young, Director of the Hemostasis and Thrombosis Center at Children's Hospital, Los Angeles, highlighted Qfitlia's unique benefits. It offers the fewest doses required by any prophylactic therapy in the treatment of hemophilia and is suitable for all hemophilia types, including those with inhibitors and hemophilia B, where unmet medical needs persist. By targeting antithrombin, which can be accurately measured using an FDA-cleared blood assay, Qfitlia has proven effective in rebalancing hemostasis and improving bleed rates and protection.

The ATLAS clinical development program has been instrumental in assessing Qfitlia's efficacy and safety. The trials exhibited low bleed rates across various patient subgroups, requiring as few as six injections annually. Significant adverse reactions remain a possibility, with potential thrombotic events, acute and recurrent gallbladder disease, and hepatotoxicity identified. Common adverse effects include viral infections, nasopharyngitis, and bacterial infections.

Alongside Qfitlia's approval, the FDA has authorized Siemens Healthineers' INNOVANCE® Antithrombin assay as a companion diagnostic tool to measure AT levels. Through the Qfitlia Testing Program with Labcorp, this FDA-cleared diagnostic will be accessible to patients prescribed Qfitlia at no additional cost. Qfitlia promises the lowest dosage requirements among prophylactic therapies, while maintaining a competitive price compared to other hemophilia treatments. The launch of HemAssist will accompany Qfitlia, offering comprehensive patient support services that include insurance and financial aid, as well as educational resources. This initiative caters to patients prescribed Qfitlia or other hemophilia treatments from Sanofi's range.

The FDA has granted Qfitlia Orphan Drug Designation for hemophilia types A and B, Fast Track Designation for hemophilia A and B with or without factor inhibitors, and Breakthrough Therapy Designation for hemophilia B with factor IX inhibitors. Regulatory submissions are currently under review in Brazil, with a decision in China anticipated in the latter half of 2025.