Pharmacotherapeutic group: antihaemorrhagics, fibrinogen, ATC code: B02BB01
Human fibrinogen (coagulation factor I), in the presence of thrombin, activated coagulation factor XIII (FXIIIa) and calcium ions, is converted into a stable and elastic three-dimensional fibrin haemostatic clot.
The administration of human fibrinogen provides an increase in plasma fibrinogen level and can temporarily correct the coagulation defect of patients with fibrinogen deficiency.
An open-label, prospective, randomised, controlled, two-arm cross-over single-dose pharmacokinetic phase 2 study in 22 patients with congenital fibrinogen deficiency (afibrinogenaemia) (see section 5.2) also evaluated the maximum clot firmness (MCF) as a surrogate marker for haemostatic efficacy (FORMA-01). MCF was determined by thromboelastometry (ROTEM) testing. For each patient, MCF was determined before (baseline) and one hour after the single-dose administration of FIBRYGA. MCF values were significantly higher after administration of FIBRYGA than at baseline (see the table below).
Table 1: Maximum clot firmness MCF [mm] (ITT population) n=22
| Time point | Mean ± SD | Median (range) |
| Pre-infusion | 0 ± 0 | 0 (0-0) |
| 1 hour post-infusion | 9.7± 3.0 | 10.0 (4.0-16.0) |
| Mean change (primary analysis)* | 9.7 ± 3.0 | 10.0 (4.0-16.0) |
MCF = maximum clot firmness; ITT = intention-to-treat.
*p < 0.0001 (95% confidence interval 8.37; 10.99)
A prospective, open label, uncontrolled, multicentre phase 3 study (FORMA-02) was conducted in 25 patients with congenital fibrinogen deficiency (afibrinogenaemia and hypofibrinogenaemia), ranging in age from 12 to 54 years (6 adolescents, 19 adults). This included the treatment of 89 bleeding episodes and 12 surgical procedures. There was significant change from baseline in the MCF as measured by ROTEM and fibrinogen plasma levels. The median dose of FIBRYGA per infusion for the treatment of bleeding episodes was 57.5 mg/kg and the median total dose was 59.4 mg/kg. The median total dose of FIBRYGA per surgery was 85.8 mg/kg. Overall haemostatic efficacy was rated as successful (rating of good or excellent efficacy) for 98.9% of the treated bleeding episodes and for 100% of the surgeries by an independent adjudication committee using an objective scoring system.
Another prospective, open label, uncontrolled, multicentre phase 3 study (FORMA-04) was conducted in 14 children with congenital fibrinogen deficiency (afibrinogenemia and hypofibrinogenemia), ranging in age from 1 to 10 years (6 <6 years of age and 8 between 6 and <12 years of age). This included the treatment of 10 bleeding episodes and 3 surgical procedures, as well as single dose pharmacokinetics. There was a significant change from baseline in the MCF as measured by ROTEM and fibrinogen plasma levels. The median dose of FIBRYGA per infusion for treatment of bleeding episodes was 70.2 mg/kg and the median total dose was 73.9 mg/kg. The median total dose of FIBRYGA per surgery was 108 mg/kg. Overall haemostatic efficacy was rated as successful (rating of good or excellent efficacy) for 100 % of the treated bleeding episodes and of the surgeries by an independent adjudication committee using an objective scoring system.
The prospective, randomised, controlled study FORMA-05 investigated the haemostatic efficacy and safety of FIBRYGA by comparison with cryoprecipitate as fibrinogen supplementation sources in patients developing acquired fibrinogen deficiency during cytoreductive surgery for the extensive abdominal malignancy pseudomyxoma peritonei. The study included 43 adult patients in the Per Protocol (PP) analysis set, 21 patients treated with FIBRYGA and 22 patients treated with cryoprecipitate. Intraoperative fibrinogen supplementation was performed pre-emptively (i.e. after 60-90 minutes in surgery, when excessive blood loss was observed, but before 2 litres of blood had been lost) with doses of 4 g of FIBRYGA or of 2 pools of 5 units of cryoprecipitate, repeated as needed. During the 7.8 ± 1.7 hours of surgery, 6.5 ± 3 g of FIBRYGA (89 ± 39 mg/kg bw) and 4.1 ± 2.2 pools of 5 units of cryoprecipitate were used, respectively. A median of 1 unit and 0.5 units RBC were administered intraoperatively to the patients treated with FIBRYGA and cryoprecipitate, respectively, with a median of 0 units RBC during the first 24 hours post-operatively in both groups (see the table below). No fresh frozen plasma or platelet concentrates were transfused during the study Haemostatic therapy based on fibrinogen supplementation was rated as successful for 100% of the surgeries in both groups by an independent adjudication committee using an objective scoring system.
Table 2: RBC* transfusion [units] intraoperatively and during the first 24 hours postoperatively (PP population)
| Time frame | FIBRYGA group (n=21) Median (range) | Cryoprecipitate group (n=22) Median (range) |
| Intraoperatively | 1 (0-4) | 0.5 (0-5) |
| First 24 hours postoperatively | 0 (0-2) | 0 (0-2) |
RBC = red blood cell concentrates; PP = per protocol.
*no transfusion of other allogeneic blood products, such as fresh frozen plasma or platelet concentrates, occurred
Paediatric population
In congenital fibrinogen deficiency, FIBRYGA was administered in two clinical studies (FORMA-02 and FORMA-04) in 20 patients from 1 to <18 years of age, of which 6 adolescents 12 to <18 years of age, 8 children 6 to <12 years of age and 6 children 1 to <6 years of age. Haemostatic efficacy was assessed as successful by an independent adjudication committee for all bleeding episodes treated (10 bleeding episodes in adolescents, 5 in children 6 to <12 years of age and 5 in children 1 to <6 years of age) and prophylaxis was also assessed as successful for the 4 surgeries performed in these patients (1 in adolescents and 3 in children 1 to <6 years of age).