Grifols Launches FESILTY™ Fibrinogen Concentrate in the U.S. for Congenital Fibrinogen Deficiency
Key Insights
Grifols announced the U.S. launch of FESILTY (search), a new human fibrinogen concentrate approved by the FDA for acute bleeding episodes in pediatric and adult patients with congenital fibrinogen deficiency (search).
FESILTY (search) offers rapid reconstitution in approximately three minutes, room-temperature storage, and predictable dosing without the need for crossmatching, unlike cryoprecipitate or fresh frozen plasma.
FDA approval was supported by a Phase I/III study (NCT02065882) with results published in Thrombosis and Haemostasis (2025) and Thrombosis Research (2026) confirming pharmacokinetics, hemostatic efficacy, and safety.
Grifols, a global healthcare company and leading producer of plasma-derived medicines, today announced the U.S. launch of FESILTY (search)™ (fibrinogen, human-chmt), a new fibrinogen concentrate approved by the U.S. Food and Drug Administration in December for the treatment of acute bleeding episodes in pediatric and adult patients with congenital fibrinogen deficiency (search) (CFD), including hypo- or afibrinogenemia. FESILTY is not indicated for dysfibrinogenemia.
The launch provides healthcare professionals with a new therapeutic option for managing acute bleeding in patients with CFD, a rare inherited condition caused by genetic mutations that impair the production or function of fibrinogen — 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.
Product Profile and Clinical Advantages
FESILTY (search) is a highly purified fibrinogen concentrate with a precisely defined amount of fibrinogen, enabling rapid and predictable restoration of fibrinogen levels — critical during bleeding events. In contrast, alternative treatment options such as cryoprecipitate and fresh frozen plasma include additional proteins, often require infusions of large volumes to achieve adequate fibrinogen levels, and take longer to prepare and administer. 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 availability of an additional fibrinogen concentrate in the U.S. is a meaningful development for clinicians caring for patients with congenital fibrinogen deficiency (search) during acute bleeding events," said Guy Young, MD, Director of the Hemostasis and Thrombosis Center at University of Southern California's Keck School of Medicine. "Targeted fibrinogen replacement is becoming increasingly well supported, and purified concentrates can be especially useful because they allow for predictable dosing, can be administered quickly and do not require crossmatching."
Clinical Evidence Supporting Approval
FDA approval of FESILTY (search) 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 (search)" (NCT02065882). Results from this study were recently published in two medical 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.
Safety Considerations
FESILTY (search) is contraindicated in patients who have severe hypersensitivity reactions, including anaphylaxis, to FESILTY or its components (arginine hydrochloride, polysorbate 80, sodium citrate dihydrate, trehalose dihydrate). Hypersensitivity reactions have occurred in patients receiving FESILTY; should symptoms occur, administration should be discontinued and appropriate treatment administered.
Thrombotic events have occurred in patients receiving FESILTY (search), including portal vein thrombosis, deep vein thrombosis, and pain in extremity with clinically suspected thrombosis. The benefits of administration should be weighed against the risks of thrombosis. One patient had an episode of epilepsy and died due to extradural hematoma four weeks after administration of FESILTY.
As FESILTY (search) is made from pooled human plasma, it may carry the risk of transmitting infectious agents, including viruses, the variant Creutzfeldt-Jakob disease (vCJD) agent, and theoretically, the Creutzfeldt-Jakob disease (CJD) agent. In the clinical study, the most common adverse reactions occurring in more than 2% of patients were pain in extremity, back pain, hypersensitivity reactions, pyrexia, thrombosis, fibrin D dimer increased, headache, and vomiting.
Strategic Significance
"With FESILTY (search) now available in the U.S., health care providers have a safe, effective and reliable treatment for acute bleeding episodes in patients with CFD — when every minute counts," said Roland Wandeler, President of Grifols Biopharma. "This milestone reflects our continued commitment to bringing more medicines to more patients around the world."
The launch of FESILTY (search) enhances Grifols' bleeding management offering and further expands its portfolio of plasma-derived medicines. Grifols, founded in Barcelona in 1909, operates in more than 110 countries with over 25,000 employees and focuses on six core therapeutic areas: immunology, neurology, pulmonology, hematology, hepatology, and intensive care.