Head-on comparative studies of factor IX (FIX) concentrates performed under standardized conditions are rarely conducted regardless of being a valuable instrument guiding health care providers towards better informed and cost-effective decisions. This study is an extension of a multicentre study that assessed the efficacy, safety and pharmacokinetics (PK) of AlphaNine(®) in 25 previously treated patients with severe haemophilia B (FIX:C ≤ 2%). After a washout period ≥ 7 days following the last PK performed with AlphaNine(®) after a dose of 65-75 IU kg(-1) , an identical PK study was performed with BeneFIX(®) on 22 of the same patients. Venous blood samples for analysis were taken at baseline and at 0.25, 0.5, 1, 3, 6, 9, 24, 48, 72 and 74 h post infusion. The outcomes of the comparison of the PK parameters were as follows: Mean (± SD) in vivo recovery (IVR) was 1.3 ± 0.4 IU dL(-1) per IU kg(-1) for AlphaNine(®) and 1.0 ± 0.3 IU dL(-1) per IU kg(-1) for BeneFIX(®) (P < 0.01). Mean terminal half-life, mean residence time, area under the curve, clearance and volume of distribution of BeneFIX(®) were 36.0 ± 12.8 h, 39.3 ± 13.9 h, 1631 ± 467 IU h dL(-1) , 0.046 ± 0.01 dL kg(-1) min(-1) and 1.75 ± 0.52 mL kg(-1) respectively. These values were not significantly different to those observed in AlphaNine(®), although BeneFIX(®) displayed higher than expected IVR values and lower than expected clearance values. In conclusion, AlphaNine(®) showed a comparable half-life, but an IVR significantly higher than that of BeneFIX(®). This dissimilarity may have implications on dosing requirements for on-demand treatment regimes affecting optimal resource allocation.

Effective treatment with factor IX (FIX) requires a thorough consideration of the properties of the concentrate to be used as replacement therapy, to date, the only available treatment for haemophilia B. The aim of the study was to determine the pharmacokinetics, clinical efficacy and safety in routine clinical use of AlphaNine(®) , a high-purity human FIX concentrate. This open, single-arm, multicentre, non-randomized trial included 25 subjects (age ≥ 12) with moderate/severe haemophilia B. Pharmacokinetics was assessed at baseline and after a 6-month follow-up. The degree of haemostasis control achieved was evaluated during a 12-month follow-up. Safety was evaluated in terms of tolerance, thrombogenicity, immunogenicity and viral safety. Mean recovery was 1.01 ± 0.19 IU dL(-1) per IU kg(-1) at baseline and 1.23 ± 0.34 IU dL(-1) per IU kg(-1) 6 months later. Terminal half-life was 34.5 ± 6.2 h and 33.7 ± 5.4 h, respectively. Ratios of each parameter between the two pharmacokinetic studies were all close to 1. A total of 1,576,890 IU AlphaNine(®) were administered in 889 infusions (mean dose per infusion: 1774 IU; 3.2 infusions per month per patient). The main reasons for infusion were mild/moderate bleeding (62.3%) and prophylaxis (20.5% continuous, 15.6% intermittent). Overall, 93.0% of the efficacy assessments were rated as excellent/good and 88.8% of bleedings resolved after the first infusion. Twenty-one adverse events were reported in eight patients, none of which was considered related to the study medication. AlphaNine(®) showed a pharmacokinetic profile in agreement with that of other plasma-derived FIX concentrates and provides safe and clinically effective substitution therapy for patients with haemophilia B.

Optimal replacement treatment in haemophilia B patients requires a good understanding of the pharmacokinetics of factor IX (FIX). The aim of this study was to compare the pharmacokinetic profile of Factor IX Grífols, a highly purified human FIX concentrate with two specific pathogen inactivation/removal steps, to that of available FIX preparations. The study was an open, non-randomized trial including 25 male subjects older than 12 years of age with severe haemophilia B. Pharmacokinetic profile of the FIX preparation regularly used by the subjects was determined as control. Pharmacokinetic profile of Factor IX Grifols was determined twice, one 7-15 days after control assessment and second after a 6 months period had elapsed. Results showed that all products had peak plasma levels of FIX:C within 30 min. Mean recovery was 1.3 +/- 0.3 IU dL(-1) per IU kg(-1) for Factor IX Grifols and 1.0 +/- 0.3 IU dL(-1) per IU kg(-1) for control products (P < 0.001). The mean terminal half-life (t(1/2)) for Factor IX Grifols was 26.7 h and 26.8 h for control product. Pharmacokinetic parameters after 6 months of treatment with Factor IX Grifols did not statistically differ from the parameters obtained with the first infusion. There were no adverse events related to Factor IX Grifols for the duration of the study. In conclusion, Factor IX Grifols has adequated pharmacokinetic properties comparable to the control plasma-derived FIX and these parameters remain stable after 6 months of treatment. Factor IX Grifols can be an effective and safe plasma-derived FIX concentrate for replacement therapy in haemophilia B patients.

Factor IX Grifols is a new high-purity plasma-derived FIX concentrate with two specific pathogen elimination steps. Until this study was performed, there were no detailed reports with an adequate number of patients on the clinical evaluation of this product. To determine the efficacy and safety of Factor IX Grifols for replacement therapy in previously treated patients with severe haemophilia B, this open, multicentre and non-randomized study included 25 male subjects over the age of 12 with severe haemophilia B. Patients underwent prophylaxis and treatment of bleeding episodes with Factor IX Grifols for 1 year. The clinical efficacy and safety of this product were assessed. Forty percent of the patients were children and adolescents (12-17 years old). During the 12 months follow-up, 1 446 000 IU of Factor IX Grifols were administered in 961 infusions (range 12-83 infusions per patient): 31% for prophylaxis and 69% for bleeding episodes. Only five major bleeding events were reported in two patients. These haemorrhages were successfully treated with a mean of 2900 IU per bleed (range 1500-4000 IU), and 1-3 infusions per bleed. The average time elapsed from the first infusion to resolution of bleeding was 43 h (median). Overall, haemostasis was rated as excellent or good by the investigator in 96% of the infusions. No product-related adverse events were reported. Factor IX Grifols is an effective and safe Factor IX concentrate and can be considered as a first line option for replacement therapy in haemophilia B patients.

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