Grifols Launches FESILTY Fibrinogen Concentrate in U.S. for Rare Bleeding Disorder

Grifols has launched FESILTY (fibrinogen, human-chmt) in the United States, a highly purified fibrinogen concentrate approved by the U.S. Food and Drug Administration in December 2025 for the treatment of acute bleeding episodes in pediatric and adult patients with congenital fibrinogen deficiency (CFD). The product, developed and produced by Biotest, a Grifols Group company, is now available as a new treatment option for CFD, a rare inherited condition caused by genetic mutations that impair the production or function of fibrinogen.

FESILTY is indicated for the treatment of acute bleeding episodes in patients with congenital fibrinogen deficiency, including hypo- or afibrinogenemia. It is not indicated for dysfibrinogenemia. Fibrinogen is a plasma protein produced in the liver that is essential for blood clotting and wound healing. When fibrinogen levels are insufficient, the body's ability to effectively control bleeding is compromised, particularly during acute bleeding episodes.

As a highly purified product with a precisely defined amount of fibrinogen, FESILTY enables rapid and predictable restoration of fibrinogen levels, which is critical during bleeding events in patients with CFD. Unlike alternate treatment options such as cryoprecipitate and fresh frozen plasma, which include additional proteins and often require infusions of large volumes to achieve adequate fibrinogen levels, FESILTY can be stored at room temperature at the point of care and is supplied as a complete kit, allowing for rapid reconstitution in approximately three minutes.

The U.S. is the second country to approve this fibrinogen concentrate. It was first approved in Germany in November 2025, where it is being commercialized by Biotest under the brand name Prufibry®. Approvals in additional European markets are expected in 2026. The product is manufactured at the "Biotest Next Level" production facility in Dreieich, Germany.

FDA approval was based on evidence from the clinical study "A Prospective, Open-label, Phase I/III Study Investigating Pharmacokinetic Properties of BT524 and Efficacy and Safety of BT524 in the Treatment and Prophylaxis of Bleeding in Patients With Congenital Fibrinogen Deficiency" (NCT02065882). Results from this study were published in the journals Thrombosis and Haemostasis (October 2025) and Thrombosis Research (March 2026), confirming the therapy's pharmacokinetics, hemostatic efficacy, and safety for treatment of acute bleeding episodes in both adults and children with CFD.

The most serious adverse reactions observed with FESILTY were thrombotic events, including portal vein thrombosis, deep vein thrombosis, and pain in extremity with clinically suspected thrombosis. In the clinical study, the most common adverse reactions occurring in more than 2% of patients included pain in extremity, back pain, hypersensitivity reactions, pyrexia, thrombosis, fibrin D-dimer increased, headache, and vomiting. FESILTY is contraindicated in patients who have severe hypersensitivity reactions, including anaphylaxis, to the product or its components. As a product made from pooled human plasma, FESILTY may carry the risk of transmitting infectious agents.