An open clinical study assessing the efficacy and safety of Factor IX Grifols®, a high-purity Factor IX concentrate, in patients with severe haemophilia B

Degradation of Aqueous Polycyclic Musk Tonalide by Ultraviolet-Activated Free Chlorine

Chlorine-incorporating ultraviolet (UV) provides a multiple barrier for drinking water disinfection. Meanwhile, post-UV employment can promote the degradation of micropollutants by radical production from chlorine residual photolysis. This work studied the degradation of one such chemical, tonalide (AHTN), by low-pressure UV-activated free chlorine (FC) under typical UV disinfection dosage of <200 mJ·cm−2 and water matrix of filtered tank effluent. AHTN was rapidly degraded by UV/FC in accordance with pseudo-first-order kinetics. The reaction rate constants of AHTN with reactive chlorine species and hydroxyl radical (HO•) were estimated. Mechanistic exploration evidenced that under UV/FC, AHTN degradation was attributable to direct photolysis, ClO•, and HO•. The carbonyl side chain of AHTN served as an important attack site for radicals. Water matrices, such as natural organic matter (NOM), HCO3−, Cu2+, PO43−, and Fe2+, showed noticeable influence on the UV/FC process with an order of NOM > HCO3− >Cu2+ > PO43− > Fe2+. Reaction product analysis showed ignorable formation of chlorinated intermediates and disinfection byproducts.

Thrombogenicity evaluation in 221 patients with haemophilia B treated with nonacog alfa

Risk for thrombotic events with factor IX replacement therapy in patients with haemophilia B remains a concern for patients, those who treat them, and regulatory agencies, based on experience with early use of prothrombin complex concentrates. The current post hoc analysis assessed the incidence of thrombotic events and changes in prothrombin fragment 1 + 2, thrombin–antithrombin complex, and d-dimer in 221 patients with haemophilia B who received nonacog alfa in clinical studies. Thrombotic event and coagulation marker data were collected from 8 interventional studies utilizing on-demand, prophylactic, and preventive regimens in patients with haemophilia B. Mean age was 25 years (min–max, 0–69), with 51 (23%) patients aged less than 12 years and 15 (7%) aged less than 2 years. None tested positive for inhibitors. Mean time on study was 60.9 ± 32 weeks and mean number of exposure days was 69.3 (min–max, 1–496). Sixty-nine (31%) patients regularly received infusions that were approximately 100 IU/kg as part of a routine prophylaxis regimen, and 29 (13%) patients underwent surgical procedures. No clinical thrombotic events were reported, and no patient experienced clinically significant changes in coagulation markers between baseline and end-of-study testing. These collective data support the low thrombotic risk associated with nonacog alfa in paediatric, adult, and surgical patients with haemophilia B receiving different treatment regimens, including doses of approximately 100 IU/kg. Although careful thrombotic clinical evaluation is important, regular coagulation marker monitoring does not appear to be warranted in patients with haemophilia B.

Long-term efficacy and safety of a pasteurized, plasma-derived factor VIII concentrate (Beriate® P) in patients with haemophilia A

Introduction

Beriate^® P was first introduced in Germany in 1990 as factor VIII (FVIII):C^® HS Behring and subsequent product improvements yielded an albumin-free formulation with a specific activity of approximately 170 IU/mg protein. In 1992, the concentration was raised to 100 IU FVIII/mL in the reconstituted product, with a mean specific activity of 270 IU/mg protein. Pathogen safety is achieved by careful donor selection and a combination of pasteurization and chromatographic purification steps.

Materials and methods

We analysed the efficacy and safety of Beriate^® P in the clinical setting from 1996 to 2005 with a focus on surgical patients. Of the 36 patients (mean age: 38 years; range 1–72 years), 29 had severe haemophilia A, two had moderate haemophilia, two had mild haemophilia, and three had sub-clinical haemophilia. Most patients (n = 28) had more than 100 exposure days, representing a total of 202 patient-years with a consumption of 27,811,500 IU of Beriate^® P.

Results

There was no evidence of seroconversion towards relevant viruses, no inhibitor development (35 previously treated patients, one previously untreated patient), no abnormal immunological findings or allergic reactions. In all 36 patients treated for acute bleeding and prophylaxis, and 24 surgeries (15 total joint replacements, eight orthopaedic procedures, one cholecystectomy) in 16 patients with severe haemophilia A, efficacy of Beriate^® P was always rated as “excellent” or “good”, and no thrombosis was reported.

Conclusion

Beriate^® P has an excellent efficacy and safety profile. Many patients who were initiated on Beriate^® P at our centre remain on the treatment today.

Pharmacokinetics of plasma-derived and recombinant factor IX - implications for prophylaxis and on-demand therapy

Plasma-derived (pd) and recombinant (r) factor IX (FIX) differ in pharmacokinetic (PK) properties. These differences and their clinical implications have been debated since the introduction of rFIX. The aim of this review was to describe the comparative disposition of pdFIX and rFIX and will for this purpose begin with an overview of population PK modelling. In contrast to the model-independent method, a population PK model can analyse sparse data sets obtained in various settings, provide parameter values that can be used to predict coagulation factor levels with any kind of single or multiple dosing and include statistical analysis of variation between individuals. Population modelling has also clearly demonstrated the difference in PK between pdFIX and rFIX. Their distribution characteristics influence the FIX coagulant activity (FIX:C) level vs. time curve during the early hours after infusion. In vivo recovery and elimination half-life are consequently not adequate descriptors of the effective PK of FIX, and for new analogues with modified PK, differences in distribution might be clinically important. Calculated doses to maintain 1% trough levels during twice-weekly prophylactic treatment are considerably higher with rFIX than with pdFIX and roughly correspond to dosing in clinical studies. However, the putative relationship between FIX:C trough level and therapeutic outcome has never been confirmed in a clinical trial. Comparative studies on prophylaxis with different types of FIX are needed.

Haemophilia B: current pharmacotherapy and future directions

INTRODUCTION

Hemophilia B is a rare hereditary hemorrhagic disorder characterized by deficiency of the clotting factor IX (FIX). Hemophilia B patients experience mild to severe bleeding complications according to the degree of FIX defect. Nowadays, the most challenging complication of individuals with hemophilia B is the development of alloantibodies, which render the standard replacement therapy with FIX concentrates ineffective, exposing them to a significantly increased morbidity and mortality.

AREAS COVERED

This review summarizes the most important events leading to the development of the current FIX products available for the treatment of hemophilia B patients. In addition, it focuses on the more recent advances in the production of new FIX molecules aimed at improving the clinical management of such patients.

EXPERT OPINION

Although the availability of plasma-derived FIX concentrates has greatly improved the clinical management of hemophilia B patients, the introduction of FIX products using recombinant DNA technology has represented the most significant therapeutic progress in hemophilia B therapy, ensuring an advanced level of safety. The development of rFIX products with extended half lives will further improve the therapeutic armamentarium for hemophilia B patients.

From whole blood to component therapy: the economic, supply/demand need for implementation of component therapy in sub-Saharan Africa

Blood may be transfused as whole blood or as one of its components. Because patients seldom require all of the components of whole blood, it makes sense to transfuse only that portion needed by the patient for a specific condition or disease. This treatment, known as "blood component therapy", allows several patients to benefit from one unit of donated whole blood. Blood components include red blood cells, plasma, platelets, and cryoprecipitate. A considerable literature has accumulated over the past decade indicating that leukocytes present in allogeneic cellular blood components, intended for transfusion, are associated with adverse effects to the recipient. These include the development of febrile transfusion reactions, graft-versus-host disease, alloimmunization to leukocyte antigens, and the immunomodulatory effects that might influence the prognosis of patients with a malignancy. Moreover, it has become evident that such leukocytes may be the vector of infectious agents such as cytomegalovirus (CMV), Human T-Lymphotrophic Virus 1/11 (HTLV-I/II), and Epstein Barr (EBV) as well as other viruses. Effective stewardship of blood ensuring that several patients potentially benefit from components derived from one unit of donated whole blood is important for economic, supply/demand reasons and to protect the national inventory at times of national blood shortage. Blood safety in developing countries can be improved by more appropriate use of blood components rather than whole blood transfusion and the provision of alternatives such as oral and intravenous iron, erythropoietin, saline and colloids. This will facilitate the optimal use of the limited blood supply. Political will and open-mindedness to innovative ways to improve supply, appropriateness, optimal use and safety of blood from all types of donors are essential to promote more evidence-based approaches to blood transfusion practice in sub-Saharan Africa.