Key Points• BAX 855, a pegylated fulllength rFVIII with extended half-life, was highly effective in the prevention and treatment of bleeding events.• No subjects receiving BAX 855 developed FVIII inhibitory antibodies nor experienced unexpected adverse events.Current management of hemophilia A includes prophylaxis with factor VIII (FVIII) replacement every 2 to 3 days. BAX 855, Baxalta's pegylated full-length recombinant FVIII (rFVIII), was designed to increase half-life and, thus, reduce the frequency of prophylactic infusions while maintaining hemostatic efficacy. BAX 855 was evaluated in previously treated patients with severe hemophilia A who were aged 12 to 65 years. A phase 1 study compared the pharmacokinetic (PK) profile of BAX 855 with that of licensed rFVIII (Advate). In a pivotal study, the annualized bleeding rate (ABR), PK parameters, and efficacy of bleeding treatment were assessed. In the phase 1 study, the mean half-life (T 1/2 ) and the mean residence time of BAX 855 compared with Advate were 1.4-to 1.5-fold higher. These results were confirmed in the pivotal study. The pivotal study met its primary endpoint: Prophylaxis with BAX 855 resulted in an ABR that was significantly lower than half the ABR of on-demand treatment (P < .0001). The median ABR was 1.9, and 39.6% of compliant subjects had no bleeding episodes during prophylaxis, whereas subjects treated ondemand had a median ABR of 41.5. BAX 855 was also efficacious for the treatment of bleeding episodes, with 95.9% of bleeding episodes treated with 1 to 2 infusions and 96.1% having efficacy ratings of excellent/good. No FVIII inhibitory antibodies or safety signals were identified. These studies provide evidence that BAX 855 was safe and efficacious for on-demand treatment and prophylaxis administered twice weekly in patients with hemophilia A.
Summary. The most problematic complication of haemophilia A treatment is the development of inhibitors to FVIII. The highest risk of developing inhibitors is during the first 20 exposure days (EDs). If the patient can be brought through this high risk period without inhibitor development, the subsequent risk is low. Therefore, as a pilot project, we developed a prophylaxis regimen for the first 20-50 EDs specifically designed to induce tolerance to the administered FVIII and to minimize inhibitor development by avoiding immunological danger signals. Twenty-six consecutive previously untreated patients (PUPs) with severe haemophilia A were treated with the new prophylaxis regimen and the incidence of inhibitor development in this group was compared with that in a historical control group of 30 consecutive PUPs treated with a standard joint protection prophylaxis regimen (40-50 IU kg )1 , three times a week). There were no significant differences between the study and control groups in patient-related inhibitor risk factors such as ethnicity (all Caucasian), severity of haemophilia (all <1% FVIII), severity of FVIII gene mutation (P < 0.0006) nor in some treatment-related factors such as product type, age at first exposure, vaccination regimen or the need for surgery. 14 of 30 subjects given standard prophylaxis but only one of the 26 subjects given the new regimen developed an inhibitor (P = 0.0003, odds ratio 0.048, 95% CI: 0.001-0.372). Our results indicate that minimizing danger signals during the first 20 EDs with FVIII may reduce the risk of inhibitor formation. These results should be confirmed in a larger prospective clinical study.
Treatment with protein C concentrate is safe in children with purpura fulminans and meningococcal septic shock and leads to dose-related increases of plasma APC and resolution of coagulation imbalances.
SummaryA highly concentrated (20%) immunoglobulin (Ig)G preparation for subcutaneous administration (IGSC 20%), would offer a new option for antibody replacement therapy in patients with primary immunodeficiency diseases (PIDD). The efficacy, safety, tolerability and pharmacokinetics of IGSC 20% were evaluated in a prospective trial in Europe in 49 patients with PIDD aged 2–67 years. Over a median of 358 days, patients received 2349 IGSC 20% infusions at monthly doses equivalent to those administered for previous intravenous or subcutaneous IgG treatment. The rate of validated acute bacterial infections (VASBIs) was significantly lower than 1 per year (0·022/patient‐year, P < 0·0001); the rate of all infections was 4·38/patient‐year. Median trough IgG concentrations were ≥ 8 g/l. There was no serious adverse event (AE) deemed related to IGSC 20% treatment; related non‐serious AEs occurred at a rate of 0·101 event/infusion. The incidence of local related AEs was 0·069 event/infusion (0·036 event/infusion, when excluding a 13‐year‐old patient who reported 79 of 162 total related local AEs). The incidence of related systemic AEs was 0·032 event/infusion. Most related AEs were mild, none were severe. For 64·6% of patients and in 94·8% of IGSC 20% infusions, no local related AE occurred. The median infusion duration was 0·95 (range = 0·3‐4·1) h using mainly one to two administration sites [median = 2 sites (range = 1–5)]. Almost all infusions (99·8%) were administered without interruption/stopping or rate reduction. These results demonstrate that IGSC 20% provides an effective and well‐tolerated therapy for patients previously on intravenous or subcutaneous treatment, without the need for dose adjustment.
• rVWF is safe, well tolerated, and has a PK profile generally comparable to pdVWF, but promotes enhanced stabilization of endogenous FVIII.Safety and pharmacokinetics (PK) of recombinant von Willebrand factor (rVWF) combined at a fixed ratio with recombinant factor VIII (rFVIII) were investigated in 32 subjects with type 3 or severe type 1 von Willebrand disease (VWD) in a prospective phase 1, multicenter, randomized clinical trial. rVWF was well tolerated and no thrombotic events, inhibitors, or serious adverse events were observed. The PK of rVWF ristocetin cofactor activity, VWF antigen, and collagen-binding activity were similar to those of the comparator plasmaderived (pd) VWF-pdFVIII. In vivo cleavage of ultra-large molecular-weight rVWF multimers by ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13; the endogenous VWF protease) and generation of characteristic satellite bands were demonstrated. In 2 subjects with specific nonneutralizing anti-VWF-binding antibodies already detectable before rVWF infusion, a reduction in VWF multimers and VWF activity was observed. Stabilization of endogenous FVIII was enhanced following post-rVWF-rFVIII infusion as shown by the difference in area under the plasma concentration curve compared with pdVWF-pdFVIII (AUC 0-' ) (P < .01). These data support the concept of administering rVWF alone once a therapeutic level of endogenous FVIII is achieved. This trial was registered at www.clinicaltrials.gov as #NCT00816660. (Blood. 2013;122(5):648-657)
Introduction: Primary factor VIII (FVIII) prophylaxis is the optimal treatment in children with severe haemophilia A. They are expected to benefit from extended half-life (T 1/2 ) FVIII coverage by reduced infusion frequency while maintaining haemostatic efficacy. Aims: To determine immunogenicity, pharmacokinetics (PK), efficacy, safety and quality of life of prophylaxis with a polyethylene glycol (peg)-ylated FVIII (BAX 855) based on full-length recombinant FVIII (ADVATE) in paediatric previously treated patients (PTPs) with severe haemophilia A. Methods: PTPs <12 years without history of FVIII inhibitors received twice-weekly infusions of 50 AE 10 IU kg À1 BAX 855 for ≥50 exposure days. Prophylactic dose increases to ≤80 IU kg À1 were allowed under predefined conditions. PK was evaluated after single infusions of 60 AE 5 IU kg
À1. Results: T 1/2 and mean residence time were extended 1.3-to 1.5-fold compared to ADVATE (n = 31), depending on the analysis used. The point estimate for the mean annualized bleeding rate in 66 subjects receiving a median of 1.9 weekly infusions of 51.3 IU kg À1 of BAX 855 each was 3.04 (median 2.0); 1.10 (median 0) for joint and 1.16 (median 0) for spontaneous bleeds. Overall, 38% of subjects had zero bleeds. No bleeds were severe. Haemostatic efficacy was rated excellent or good for 90% of bleeds; 91% were treated with one or two infusions. In 8/14 subjects all target joints resolved. No subject developed FVIII inhibitors or persistent binding antibodies that affected safety or efficacy. No adverse reactions occurred. Conclusion: Twice-weekly prophylaxis with BAX 855 was safe and efficacious in paediatric PTPs with severe haemophilia A.
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