Efficacy and safety of fibrinogen concentrate for perioperative prophylaxis of bleeding in adult, adolescent, and pediatric patients with congenital fibrinogen deficiency: FORMA‐02 and FORMA‐04 clinical trials

Background: Congenital fibrinogen deficiency (CFD) is a rare coagulation disorder placing patients at increased bleeding risk. Human fibrinogen concentrate (HFC) represents current standard of care for fibrinogen replacement in CFD, however, limited data are available on HFC for prophylactic administration before/during surgery. Here, we report results and dosing considerations for HFC treatment in perioperative bleeding management in adult, adolescent, and pediatric patients with CFD. Study design and methods: FORMA-02/FORMA-04 were multinational, prospective, open-label, uncontrolled Phase 3 HFC efficacy/safety studies for surgical bleeding prophylaxis in adult/adolescent (≥12 years) and pediatric patients (<12 years) respectively. HFC dosing was calculated to achieve pre-established target fibrinogen plasma levels. Overall hemostatic efficacy was assessed as success/failure by an Independent Data Monitoring and Endpoint Adjudication Committee (IDMEAC) according to objective criteria. Results: Twelve patients (≥12 years, N = 9; <12 years, N = 3) received HFC for surgical prophylaxis (15 surgeries; 13 minor, 2 major). Eleven minor surgeries in patients aged ≥12 years required a median of 1 infusion (range; 1-5), with a mean (±SD) dose of 93.50 mg/kg [±41.43] and two minor surgeries in patients <12 years required 1 infusion (91.55 mg/kg [±23.40]). The major surgery in an adult patient required eight infusions (225.3 mg/kg total dose). The major surgery in a pediatric patient required six infusions (450.4 mg/kg). All surgeries were rated successful by the IDMEAC. Discussion: In adults/adolescents and pediatric patients with fibrinogen deficiency, HFC treatment for hemostatic management during/after minor and major surgery was successful, with efficacy comparable across the different age groups.