The US Food and Drug Administration (FDA) has approved Grifols’ fibrinogen, human-chmt, branded as Fesilty, to treat acute bleeding episodes in patients with congenital fibrinogen deficiency (CFD). This includes individuals with hypo- or afibrinogenemia. The announcement was made on December 19, 2025, and Grifols plans to launch the product in the United States during the first half of 2026.
In a statement, Roland Wandeler, President of Grifols Biopharma, expressed enthusiasm about the approval. “With the approval of Fesilty, we are excited to provide U.S. healthcare providers and patients with CFD a safe, effective and reliable treatment for acute bleeding episodes—when every minute counts,” he noted. This advancement reflects Grifols’ commitment to expanding access to essential medicines globally.
Congenital fibrinogen deficiency is a rare genetic disorder that affects the body’s ability to produce or function properly with fibrinogen, a plasma protein critical for blood clotting and wound healing. Patients with insufficient fibrinogen levels face challenges in controlling bleeding, especially during acute incidents. Current treatment options include fresh frozen plasma, cryoprecipitate, or fibrinogen concentrates. However, these alternatives often require large volume infusions, which may include additional proteins not necessary for effective treatment.
Fesilty is designed specifically to address the needs of patients with CFD by providing a concentrated source of fibrinogen. It is manufactured at the Biotest Next Level production facility in Dreieich, Germany. This marks the second country to approve this new fibrinogen concentrate, following Germany’s approval in November 2025, where it is marketed under the brand name Prufibry. Additional approvals in European markets are anticipated in 2026.
The FDA’s approval was based on data from a clinical study titled “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.” The study evaluated the safety and efficacy of Fesilty, highlighting its potential to significantly improve patient outcomes.
Despite the promising results, the clinical study noted serious adverse reactions associated with Fesilty. These included thrombotic events such as portal vein thrombosis and deep vein thrombosis, alongside reports of extremity pain related to suspected thrombosis. One patient experienced an episode of epilepsy leading to death, attributed to an extradural hematoma occurring four weeks after administration of the product.
The most common adverse reactions reported in over 2% of patients receiving Fesilty included extremity pain, back pain, hypersensitivity reactions, fever, thrombosis, increased fibrin D dimer levels, headaches, and vomiting.
As Grifols prepares for the launch of Fesilty, healthcare providers and patients look forward to a new option that addresses the urgent needs of those affected by congenital fibrinogen deficiency.
