Barcelona-based biopharmaceutical firm Grifols has announced that its fibrinogen concentrate therapy, BT524, is on track for commercial rollout in Europe later this year, with US approval expected by early 2026.
The development follows the publication of Phase III trial results in eClinicalMedicine, a journal under The Lancet Discovery Science Suite.
The study, known as AdFIrst (Adjusted Fibrinogen Replacement Strategy), evaluated the efficacy and safety of BT524 in managing acquired fibrinogen deficiency (AFD) during major surgeries. The therapy met its primary endpoint by demonstrating non-inferiority to standard-of-care (SOC) treatments, such as cryoprecipitate and fresh-frozen plasma (FFP), in controlling intraoperative bleeding.
“We look forward to finalizing regulatory approval processes in Europe and the United States as soon as possible,” said Dr. Jörg Schüttrumpf, Grifols’ Chief Scientific Innovation Officer. The company plans to present further data through three abstracts at the International Society on Thrombosis and Haemostasis (ISTH) Congress in Washington, D.C., later this month.
How BT524 Works
Fibrinogen is a vital plasma protein synthesized by the liver that plays a central role in hemostasis—the process that stops bleeding. When blood vessels are injured, fibrinogen is converted into fibrin strands that stabilize blood clots and assist in wound healing. A fibrinogen deficiency, whether inherited or acquired, can result in severe, uncontrolled bleeding episodes, particularly during surgery, trauma, or postpartum hemorrhage.
Acquired fibrinogen deficiency (AFD) is commonly treated using FFP or cryoprecipitate, both of which come with notable limitations. These blood components require thawing and preparation before administration, delaying urgent treatment. Moreover, they contain variable amounts of fibrinogen, complicating dosing precision.
BT524 addresses these challenges by providing a concentrated, standardized dose of fibrinogen that can be administered rapidly without the need for thawing. This makes the therapy not only more efficient but also more predictable and patient-specific. By improving response time and dosing accuracy, BT524 could significantly enhance clinical outcomes in settings where bleeding must be controlled quickly.
Grifols already has experience in this space, having previously launched a fibrinogen-based fibrin sealant for surgical bleeding.
Inside the AdFIrst Trial
The AdFIrst trial was a randomized, active-controlled, multicenter Phase III study (NCT03444324) designed to compare BT524 to traditional therapies in patients undergoing high-risk spinal or abdominal surgeries. Participants who experienced significant blood loss during these procedures were randomly assigned to receive either BT524 or SOC therapies (cryoprecipitate or FFP).
The trial’s primary endpoint focused on measuring intraoperative blood loss from the decision to treat until the end of surgery. BT524 demonstrated non-inferiority with a measured intraoperative blood loss of 1,381 mL compared to 1,660 mL in the SOC group—a difference of 279 mL favoring BT524. The non-inferiority margin was set at 150 mL, and the results comfortably met this benchmark.
Additionally, the trial found a statistically significant reduction in thromboembolic events (TEEs) among patients treated with BT524, underscoring its favorable safety profile. Safety assessments were conducted on all patients who received at least one dose of the study drug.
Dr. Niels Rahe-Meyer of Hannover Medical School, who coordinated the study, emphasized the significance of the findings. “These data could represent a breakthrough in our understanding of hemorrhage management with fibrinogen,” he said, pointing to the trial’s contribution to advancing evidence-based strategies for surgical bleeding.
BT524’s performance in the AdFIrst trial adds to a growing body of evidence supporting the use of fibrinogen concentrates in managing bleeding disorders.
