Turoctocog alfa pegol (N8-GP) is a novel glycoPEGylated extended half-life recombinant factor VIII (FVIII) product developed for prophylaxis and treatment of bleeds in patients with haemophilia A, to enable higher activity levels with less frequent injections compared with standard FVIII products. This phase III (NCT01480180), multinational, open-label, non-randomised trial evaluated the safety and clinical efficacy of N8-GP when administered for treatment of bleeds and for prophylaxis, in previously treated patients aged ≥12 years with severe haemophilia A. Patients were allocated to receive N8-GP for prophylaxis or on-demand treatment for up to 1.8 years. Patients on prophylaxis were administered one dose of 50 IU/kg of N8-GP every fourth day. Bleeds were treated with doses of 20-75 IU/kg. Total exposure to N8-GP in the trial was 14,114 exposure days (159 patient-years). For the prophylaxis arm (n=175), the median annualised bleeding rate (ABR) was 1.33 (interquartile range, 0.00-4.61), the mean ABR was 3.70 (95 % confidence interval 2.94-4.66) and 70 (40 %) patients had no bleeds during the trial. Across treatment arms, 83.6 % of bleeds resolved with one injection and 95.5 % with up to two injections. N8-GP had a favourable safety profile and was well tolerated. The frequency and types of adverse events reported were as expected in this population. One patient developed inhibitory antibodies against FVIII (≥0.6 Bethesda units [BU]) after 93 N8-GP exposure days. No clinically significant safety concerns were identified and N8-GP was effective for prophylaxis and treatment of bleeds in previously treated patients.

Key Points rVIII-SingleChain is a novel rFVIII, designed to have high stability and high binding affinity for VWF. In severe hemophilia A patients, rVIII-SingleChain was well tolerated and resulted in low bleeding rates, when dosed twice per week.

BackgroundBAY 81-8973 is a new full-length human recombinant factor VIII product manufactured with technologies to improve consistency in glycosylation and expression to optimize clinical performance.ObjectivesTo demonstrate superiority of prophylaxis vs. on-demand therapy with BAY 81-8973 in patients with severe hemophilia A.Patients/MethodsIn this multinational, randomized, open-label crossover study (LEOPOLD II; ClinicalTrials.gov identifier: NCT01233258), males aged 12–65 years with severe hemophilia A were randomized to twice-weekly prophylaxis (20–30 IU kg−1), 3-times-weekly prophylaxis (30–40 IU kg−1), or on-demand treatment with BAY 81-8973. Potency labeling for BAY 81-8973 was based on the chromogenic substrate assay or adjusted to the one-stage assay. Primary efficacy endpoint was annualized number of all bleeds (ABR). Adverse events (AEs) and immunogenicity were also assessed.ResultsEighty patients (on demand, n = 21; twice-weekly prophylaxis, n = 28; 3-times-weekly prophylaxis, n = 31) were treated and analyzed. Mean ± SD ABR was significantly lower with prophylaxis (twice-weekly, 5.7 ± 7.2; 3-times-weekly, 4.3 ± 6.5; combined, 4.9 ± 6.8) vs. on-demand treatment (57.7 ± 24.6; P < 0.0001, anova). Median ABR was reduced by 97% with prophylaxis (twice-weekly, 4.0; 3-times-weekly, 2.0; combined, 2.0) vs. on-demand treatment (60.0). Median ABR was higher with twice-weekly vs. 3-times-weekly prophylaxis during the first 6-month treatment period (4.1 vs. 2.0) but was comparable in the second 6-month period (1.1 vs. 2.0). Few patients reported treatment-related AEs (4%); no treatment-related serious AEs or inhibitors were reported.ConclusionsTwice-weekly or 3-times-weekly prophylaxis with BAY 81-8973 reduced median ABR by 97% compared with on-demand therapy, confirming the superiority of prophylaxis. Treatment with BAY 81-8973 was well tolerated.

Laboratory evaluation of bleeding disorders has been performed with the standard clotting assays such as the PT and PTT for several decades. Our improved understanding of the process of blood coagulation has now revealed the important role played by the cellular elements such as platelets, monocytes and red blood cells. The need for a test that can assess clotting in a more 'global' manner, beyond the initiation of clot formation, has led to greater interest in assays such as thrombin generation and thromboelastography. Even though there are several publications using thromboelastography it remains a research tool as the methodology is not standardized. In an attempt to show reproducibility and consistency using thromboelastography, a group of investigators from different countries joined hands to form the TEG-ROTEM Working Group. Two studies were performed using PRP and FVIII deficient plasma and an intrinsic pathway activator. This article summarizes the results of the first international effort at standardization of thromboelastography. Both of the instruments using this technology (TEG(®) and ROTEM(®)) were used. Nine laboratories from countries around the globe participated in this effort. The results showed a significant inter-laboratory variance with CV's greater than 10%. Although these results were not satisfactory, this has been the first effort to standardize this methodology and significant work remains to be done to improve reliability and reproducibility. These studies were performed on PRP and the results may be more reliable when preformed on whole blood samples. We believe that it is important to continue this work so that we may investigate the usefulness and potential applications of thromboelastography in the evaluation of bleeding and thrombosis.

Gene therapy has the potential to maintain therapeutic blood clotting factor IX (FIX) levels in patients with hemophilia B by delivering a functional human F9 gene into liver cells. This phase 1/2, open-label dose-escalation study investigated BAX 335 (AskBio009, AAV8.sc-TTR-FIXR338Lopt), an adeno-associated virus (AAV) serotype 8-based FIX Padua gene therapy, in patients with hemophilia B. This report focuses on 12-month interim analyses of safety, pharmacokinetics, effects on FIX activity, and immune responses for dosed participants. Eight adult males (\aged 20-69 years; range FIX activity, 0.5%-2.0%) received 1 of 3 BAX 335 IV doses: 2.0 × 1011; 1.0 × 1012; or 3.0 × 1012 vector genomes/kg. Three (37.5%) participants had 4 serious adverse events (SAEs), all considered unrelated to BAX 335. No SAE led to death. No clinical thrombosis, inhibitors, or other FIX Padua-directed immunity were reported. FIX expression was measurable in 7 of 8 participants; peak FIX activity displayed dose dependence (32.0%-58.5% in cohort 3). One participant achieved sustained therapeutic FIX activity of ~20%, without bleeding or replacement therapy, for 4 years; in others, FIX activity was not sustained beyond 5-11 weeks. In contrast to some previous studies, corticosteroid treatment did not stabilize FIX activity loss. We hypothesize that the loss of transgene expression could have been caused by stimulation of innate immune responses including CpG oligodeoxynucleotides introduced into the BAX 335 coding sequence by codon optimization. Registered at www.clinicaltrials.gov as NCT01687608.

Summary Background Twenty-five percent of new anti-factor VIII (FVIII) antibodies (inhibitors) that complicate hemophilia A occur in those with mild and moderate disease. Although intensive FVIII treatment has long been considered a risk factor for inhibitor development in those with non-severe disease, its strength of association and the influence of other factors have remained undefined. Objective To evaluate risk factors for inhibitor development in patients with non-severe hemophilia A. Methods Information on clinical and demographic variables and FVIII genotype was collected on 36 subjects with mild or moderate hemophilia A and an inhibitor and 62 controls also with mild or moderate hemophilia A but without an inhibitor. Results Treatment with FVIII for six or more consecutive days during the prior year was more strongly associated with inhibitor development in those ≥ 30 years of age compared with those < 30 years of age [adjusted odds ratio (OR) 12.62; 95% confidence interval (CI), 2.76–57.81 vs. OR 2.54; 95% CI, 0.61–10.68]. Having previously received < 50 days of FVIII was also not statistically associated with inhibitor development on univariate or multivariate analysis. Conclusions These findings suggest that inhibitor development in mild and moderate hemophilia A varies with age, but does not vary significantly with lifetime FVIII exposure days: two features distinct from severe hemophilia A.

Planning and undertaking elective surgery in people with haemophilia (PWH) is most effective with the involvement of a specialist and experienced multidisciplinary team (MDT) at a haemophilia treatment centre. However, despite extensive best practice guidelines for surgery in PWH, there may exist a gap between guidelines and practical application. For this consensus review, an expert multidisciplinary panel comprising surgeons, haematologists, nurses, physiotherapists and a dental expert was assembled to develop practical approaches to implement the principles of multidisciplinary management of elective surgery for PWH. Careful preoperative planning is paramount for successful elective surgery, including dental examinations, physical assessment and prehabilitation, laboratory testing and the development of haemostasis and pain management plans. A coordinator may be appointed from the MDT to ensure that critical tasks are performed and milestones met to enable surgery to proceed. At all stages, the patient and their parent/caregiver, where appropriate, should be consulted to ensure that their expectations and functional goals are realistic and can be achieved. The planning phase should ensure that surgery proceeds without incident, but the surgical team should be ready to handle unanticipated events. Similarly, the broader MDT must be made aware of events in surgery that may require postoperative plans to be changed. Postoperative rehabilitation should begin soon after surgery, with attention paid to management of haemostasis and pain. Surgery in patients with inhibitors requires even more careful preparation and should only be undertaken by an MDT experienced in this area, at a specialized haemophilia treatment centre with a comprehensive care model.

Antibody hydrolysis of the superantigenic gp120 site and HIV-1 neutralization was studied as a potential anti-HIV mechanism in uninfected humans. gp120 hydrolysis by purified serum and salivary antibodies was determined by electrophoresis and peptide sequencing, the proteolytic mechanism was analyzed using electrophilic peptide analogs, and viral neutralization was studied using peripheral blood mononuclear cells as hosts. Polyclonal and monoclonal IgA but not IgG preparations selectively catalyzed the cleavage of HIV gp120 at rates sufficient to predict biologically relevant protection against the virus. The IgA hydrolytic reaction proceeded by noncovalent recognition of gp120 residues 421-433, a component of the superantigenic site of gp120, coordinated with peptide bond cleavage via a serine protease-like mechanism. The Lys-432-Ala-433 bond was one of the cleavage sites. Infection of peripheral blood mononuclear cells by a primary isolate of HIV was neutralized by the IgA but not IgG fractions. The neutralizing activity was specifically inhibited by an electrophilic inhibitor of the catalytic activity. The existence of catalytic IgAs to gp120 in uninfected humans suggests their role in resistance to HIV.