The effects of emicizumab on in vitro coagulation and fibrinolysis parameters in patients with disseminated intravascular coagulation with and without addition of anti-FVIII antibody.

BACKGROUND: Emicizumab (Emi) is used as haemostatic prophylaxis for patients with haemophilia A (PwHA). Disseminated intravascular coagulation (DIC) is a condition characterized by persistent systemic activation of coagulation, but there is yet no information on coagulation and fibrinolysis potentials in Emi-treated PwHA with DIC. AIM: To examine the effect of Emi on coagulation and fibrinolysis potentials in HA-model DIC plasmas. METHODS: Plasma from a patient with sepsis-DIC (seven patients) was treated with anti-factor (F)VIII monoclonal antibody (HA-model DIC plasma) and incubated with Emi (50 µg/mL). The plasma was then assessed using clot-fibrinolysis waveform analysis (CFWA). Coagulation and fibrinolysis parameters were expressed as ratios relative to normal plasma (|min1|-ratio and |FL-min1|-ratio, respectively). PATIENTS AND RESULTS: In case 1, coagulant potential was slightly high and fibrinolytic potential was extremely low, presenting a coagulant-dominant state (|min1|-ratio/|FL-min1|-ratio: 1.1/.38). In cases 2-5, fibrinolytic potential was not suppressed, but there were marked hypercoagulant potentials, indicating relative coagulant-dominant states. In case 6, coagulant and fibrinolytic potentials were increased but well balanced (|min1|-ratio/|FL-min1|-ratio: 1.38/1.28). In case 7, both potentials were severely deteriorated in not only CFWA but also the thrombin/plasmin generation assay. The addition of Emi into the HA-model DIC plasmas increased |min1|-ratio values in all cases, but the coagulant potentials did not exceed the initial ones (DIC plasma before treatment with anti-FVIII antibody). CONCLUSIONS: The presence of Emi in the HA-model DIC plasma improved coagulation potentials, but did not increase coagulation potentials beyond those of DIC plasma in non-HA states.

Pharmacokinetic-Pharmacodynamic Modelling in Hemophilia A: Relating Thrombin and Plasmin Generation to Factor VIII Activity After Administration of a VWF/FVIII Concentrate.

BACKGROUND: Hemophilia A patients are treated with factor (F) VIII prophylactically to prevent bleeding. In general, dosage and frequency are based on pharmacokinetic measurements. Ideally, an alternative dose adjustment can be based on the hemostatic potential, measured with a thrombin generation assay (TGA), like the Nijmegen hemostasis assay. OBJECTIVE: The objective of this study was to investigate the predicted performance of a previously developed pharmacokinetic-pharmacodynamic model for FVIII replacement therapy, relating FVIII dose and FVIII activity levels with thrombin and plasmin generation parameters. METHODS: Pharmacokinetic and pharmacodynamic measurements were obtained from 29 severe hemophilia A patients treated with pdVWF/FVIII concentrate (Haemate P®). The predictive performance of the previously developed pharmacokinetic-pharmacodynamic model was evaluated using nonlinear mixed-effects modeling (NONMEM). When predictions of FVIII activity or TGA parameters were inadequate [median prediction error (MPE) > 20%], a new model was developed. RESULTS: The original pharmacokinetic model underestimated clearance and was refined based on a two-compartment model. The pharmacodynamic model displays no bias in the observed normalized thrombin peak height and normalized thrombin potential (MPE of 6.83% and 7.46%). After re-estimating pharmacodynamic parameters, EC50 and Emax values were relatively comparable between the original model and this group. Prediction of normalized plasmin peak height was inaccurate (MPE 58.9%). CONCLUSION: Our predictive performance displayed adequate thrombin pharmacodynamic predictions of the original model, but a new pharmacokinetic model was required. The pharmacodynamic model is not factor specific and applicable to multiple factor concentrates. A prospective study is needed to validate the impact of the FVIII dosing pharmacodynamic model on bleeding reduction in patients.

Synergistic effects of MFG-E8 and whey protein on mitigating d-galactose-induced sarcopenia through PI3K/AKT/PGC-1α and MAPK/ERK signaling pathways.

Milk fat globule epidermal growth factor 8 (MFG-E8) and whey protein have emerged as promising bionutrient supplements for enhancing skeletal muscle mass and function. In the present study, aging-related sarcopenia rat model was employed to elucidate the effects of the combined administration of MFG-E8 and whey protein on the catabolism and anabolism of gastrocnemius protein. Combined intervention led to notable enhancements in the antioxidative stress status and mitochondrial biogenesis capacity of gastrocnemius muscle fibers in the aging rats, concomitant with a significant inhibition of lipid accumulation. Moreover, the synergistic effect of MFG-E8 and whey protein was found to exert modulatory effects on key signaling pathways, including PI3K/Akt/PGC-1α pathway and MAPK/ERK signaling pathways in the gastrocnemius muscle of the aging rats. Specifically, this combined intervention was observed to promote mitochondrial biogenesis and regulate the expression of protein anabolism and catabolism-related regulators, thereby facilitating the alleviation of mitochondrial oxidative stress and enhancing biogenesis in gastrocnemius tissues. The findings of our study provide compelling evidence for the potential of MFG-E8 as a promising dietary supplement with antisarcopenic properties to ameliorate muscle protein metabolism disorders and mitigate mitochondrial-mediated myoblast apoptosis induced by oxidative stress.

Physical exercise in patients with testicular cancer treated with bleomycin, etoposide and cisplatin chemotherapy: pulmonary and vascular endothelial function-an exploratory analysis.

PURPOSE: Bleomycin, etoposide, and cisplatin combination chemotherapy (BEP) improves the survival of patients with testicular cancer, but is associated with potentially life-threatening toxicities like pneumonitis and thromboembolic events. This study explored the effects of physical exercise in patients with testicular cancer during or after BEP-chemotherapy on pulmonary and vascular endothelial toxicity. METHODS: In this post hoc analysis of a multicenter randomized clinical trial (NCT01642680), patients with metastatic testicular cancer scheduled to receive BEP-chemotherapy were randomized to a 24-week exercise intervention, initiated during (group A) or after BEP-chemotherapy (group B). Endpoints were pulmonary function (forced vital capacity (FVC), forced expiratory volume in one second (FEV1), lung transfer-coefficient and transfer factor for carbon monoxide (KCO, DLCO) and markers of vascular endothelial dysfunction (von Willebrand factor (vWF) and factor VIII). RESULTS: Thirty patients were included. Post-chemotherapy, patients declined less in FVC, FEV1 and DLCO in group A compared to group B. Post-chemotherapy, vWF and factor VIII were significantly lower in group A compared to group B. After completion of exercise, started either during BEP-chemotherapy or thereafter, no between-group differences were found. At 1-year post-intervention, significant between-group differences were found in favour of group A in DLCO and KCO. CONCLUSIONS: Patients who exercised during BEP-chemotherapy better preserved FVC, FEV1 and DLCO, measured directly post-chemotherapy and 1-year post-intervention (DLCO, KCO). This coincided with less increase in vWF and factor VIII measured directly post-chemotherapy. These data support a beneficial role of a physical exercise intervention during BEP-chemotherapy on pulmonary and vascular damage in patients with testicular cancer. TRIAL REGISTRY: Optimal Timing of Physical Activity in Cancer Treatment (ACT) Registry URL: https://clinicaltrials.gov/ct2/show/NCT01642680 . TRIAL REGISTRATION NUMBER: NCT01642680.

Effects of PK-guided prophylaxis on clinical outcomes and FVIII consumption for patients with moderate to severe Haemophilia A.

INTRODUCTION: In recent years, there has been increased focus on individualizing treatment for persons with hemophilia including pharmacokinetic-guided (PK) dosing. AIMS: In this retrospective study clinical outcomes before and after PK-guided prophylaxis were examined. MATERIALS AND METHODS: Eight Haemophilia Treatment Centres from the United States participated in the study and included 132 patients classified into two cohorts: those undergoing a PK-assessment for product switch (switchers) or to optimize treatment (non-switchers). Subset analyses for the two most common products and patients with dosing per prescription label were included for annual bleeding rates (ABR), mean weekly consumption outcomes, and annualized cost of prophylaxis. RESULTS: The most common products before and after index date were octocog alfa, rurioctocog alfa pegol, and efmoroctocog alfa. Seventy-four (56%) patients were identified as switchers and 58 (44%) patients were classified as non-switchers. The majority of patients (78.0%) experienced either a decrease in ABR post-index or maintained 0 ABR during pre- and post-index time periods, with similar proportions identified in both switchers (77.0%) and non-switchers (79.3%) populations. Non-switchers were identified as having no significant change in cost of therapy, while switchers experienced increased cost of therapy driven by higher price of extended half-life products. Within subset analyses, patients receiving rurioctocog alfa pegol and efmoroctocog alfa had mean ABR under 1 after index date. CONCLUSION: PK-guided prophylaxis has the potential to improve clinical outcomes without increase in cost of therapy for patients maintaining product and can aid in maintaining effective protection against bleeds in those switching product.

TNFAIP8 overexpression aggravates retinal pathophysiological features of diabetic retinopathy.

Our previous research shown that tumor necrosis factor-alpha-induced protein 8 (TNFAIP8) is elevated in the plasma extracellular vesicles and vitreous humor in diabetic retinopathy (DR). TNFAIP8 also significantly increases the viability of human retinal microvascular endothelial cells (HRMECs) and promotes cell migration and tube formation in vitro. To comprehensively explore its role in DR, we investigated the effect of TNFAIP8 on DR development using an animal model in this study. A TNFAIP8-overexpressing adeno-associated virus (AAV) vector and streptozotocin-induced mouse model was used. The AAV-TNFAIP8 vector was injected into the mice intravitreally, and the effect was evaluated. The evaluation included analysis of retinal structure and function using electroretinography, optical coherence tomography, and histological assessment. The influence of TNFAIP8 on the avascular area, retinal leukostasis, and the expression levels of inflammatory factors was also determined. TNFAIP8 significantly decreased a/b-wave amplitude and retinal thickness in diabetic mice. Histological assessment showed that TNFAIP8 aggravated pathological abnormalities with distorted organization of the retina. TNFAIP8 also significantly increased the avascular area, leukostasis, and the expression of inflammatory factors, such as TNFα, IL1ß, ICAM1, and GFAP, in the retina. The results of this study support the role of TNFAIP8 in DR pathogenesis. A mechanistic understanding of TNFAIP8 may offer novel therapeutic strategies.

Emicizumab for acquired haemophilia A: A case series.

BACKGROUND: Emicizumab is approved to prevent bleeding in patients with congenital haemophilia A with or without inhibitors. However, no randomized trials addressed the efficacy of emicizumab in acquired haemophilia A (AHA). AIMS: To report the clinical and biochemical response of emicizumab in AHA. METHODS: This single-centre retrospective study included seven adults with AHA between November 2020 and May 2022. We collected patient characteristics, laboratory coagulation parameters, the use of haemostatic agents, bleeds and thrombotic events. Treatment was monitored using chromogenic FVIII assays. The assay with human reagents assesses both the emicizumab FVIII-like-activity and native patient FVIII-activity. The assay with bovine reagents only measures the patients' native FVIII-activity as emicizumab does not bind to bovine reagents. RESULTS: Patients presented with spontaneous hematoma (n = 7), intramuscular bleeding (n = 2), haematuria (n = 2) and/or gastro-intestinal bleeding (n = 2). Six patients had major bleedings. At diagnosis, APTT was prolonged (91 seconds, IQR 73-103), FVIII activity was 0% (IQR 0-1) and FVIII inhibitor 182 BU/mL (IQR 104-228). Emicizumab was administered weekly (3 mg/kg) for 4 weeks, and thereafter every 2 weeks until regression of the inhibitor. Three patients received activated FVIIa (cumulative dose of 1.7 mg/kg, IQR 1.2-2.2). All bleedings were controlled after treatment initiation, without further bleeds. After starting emicizumab, FVIII-like activity reached ≥5% at 12 days (IQR 7-14), whereas recovery of the intrinsic FVIII-activity ≥5% occurred at 128 days (IQR 88-173), coinciding with the disappearance of the FVIII inhibitor. There were no safety issues. CONCLUSION: In this AHA case series, no new clinically relevant bleeds were observed after initiation of emicizumab in conjunction with standard immunosuppressive therapy.

Sensitive Measurement of Clinically Relevant Factor VIII Levels in Thrombin Generation Assays Requires Presence of Factor XIa.

BACKGROUND: Hemophilia A (HA) is characterized by decreased or absent factor VIII (FVIII) activity. Current FVIII assays are based on clotting time and thus only provide information about the initiation of coagulation. In contrast, thrombin generation assays (TGAs) can be used to measure the full coagulation spectrum of initiation, propagation, and termination that provide information on the whole course of thrombin generation and inhibition. However, the commercially available TG kits lack sensitivity for measurements of hemophilia plasma within lower FVIII ranges, which is essential for explaining differences in bleeding phenotypes in hemophiliacs at clinically low levels of FVIII. AIMS: Optimization of the TGA for measurements of low FVIII levels in severe HA patients. METHODS: TGA measurements were performed in severe HA pooled plasma (n = 10). Investigations of several preanalytical and analytical variables of the assay were performed in a stepwise process and adjusted based on sensitivity toward intrinsic coagulation activation. RESULTS: TGA initiated by tissue factor (TF) alone at varying concentrations was unable to significantly differentiate between FVIII levels below 20%. In contrast, TGA activation with low concentrations of TF in presence of FXIa appeared to be highly sensitive for FVIII changes both in high and low ranges. In addition, a representative TGA curve at trough levels could only be produced using the dual TF/FXIa TGA. CONCLUSION: We propose a critical optimization for the setup of the TGA for measurements in severe HA plasma. The dual TF/FXIa TGA shows increased sensitivity, especially in lower FVIII ranges, which allows for better individual characterization at baseline, prediction of interventions, and follow-up.

MFG-E8 promotes osteogenic differentiation of human bone marrow mesenchymal stem cells through GSK3ß/ß-catenin signaling pathway.

Fracture nonunion and bone defects are challenging for orthopedic surgeons. Milk fat globule-epidermal growth factor 8 (MFG-E8), a glycoprotein possibly secreted by macrophages in a fracture hematoma, participates in bone development. However, the role of MFG-E8 in the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) is unclear. We investigated the osteogenic effect of MFG-E8 in vitro and in vivo. The CCK-8 assay was used to assess the effect of recombinant human MFG-E8 (rhMFG-E8) on the viability of hBMSCs. Osteogenesis was investigated using RT-PCR, Western blotting, and immunofluorescence. Alkaline phosphatase (ALP) and Alizarin red staining were used to evaluate ALP activity and mineralization, respectively. An enzyme-linked immunosorbent assay was conducted to evaluate the secretory MFG-E8 concentration. Knockdown and overexpression of MFG-E8 in hBMSCs were established via siRNA and lentivirus vector transfection, respectively. Exogenous rhMFG-E8 was used to verify the in vivo therapeutic effect in a tibia bone defect model based on radiographic analysis and histological evaluation. Endogenous and secretory MFG-E8 levels increased significantly during the early osteogenic differentiation of hBMSCs. Knockdown of MFG-E8 inhibited the osteogenic differentiation of hBMSCs. Overexpression of MFG-E8 and rhMFG-E8 protein increased the expression of osteogenesis-related genes and proteins and enhanced calcium deposition. The active ß-catenin to total ß-catenin ratio and the p-GSK3ß protein level were increased by MFG-E8. The MFG-E8-induced enhanced osteogenic differentiation of hBMSCs was partially attenuated by a GSK3ß/ß-catenin signaling inhibitor. Recombinant MFG-E8 accelerated bone healing in a rat tibial-defect model. In conclusion, MFG-E8 promotes the osteogenic differentiation of hBMSCs by regulating the GSK3ß/ß-catenin signaling pathway and so, is a potential therapeutic target.

The spleen is the major site for the development and expansion of inhibitor producing-cells in hemophilia A mice upon FVIII infusion developing high-titer inhibitor.

BACKGROUND: Hemophilia A (HA) is a hereditary bleeding disorder caused by defects in endogenous factor (F)VIII. Approximately 30 % of patients with severe HA treated with FVIII develop neutralizing antibodies (inhibitors) against FVIII, which render the therapy ineffective. The managements of HA patients with high-titter inhibitors are especially challenging. Therefore, it is important to understand the mechanism(s) of high-titer inhibitor development and dynamics of FVIII-specific plasma cells (FVIII-PCs). AIMS: To identify the dynamics of FVIII-PCs and the lymphoid organs in which FVIII-PCs are localized during high-titer inhibitor formation. METHODS AND RESULTS: When FVIII-KO mice were intravenously injected with recombinant (r)FVIII in combination with lipopolysaccharide (LPS), a marked enhancement of anti-FVIII antibody induction was observed with increasing FVIII-PCs, especially in the spleen. When splenectomized or congenitally asplenic FVIII-KO mice were treated with LPS + rFVIII, the serum inhibitor levels decreased by approximately 80 %. Furthermore, when splenocytes or bone marrow (BM) cells from inhibitor+ FVIII-KO mice treated with LPS + rFVIII were grafted into immune-deficient mice, anti-FVIII IgG was detected only in the serum of splenocyte-administered mice and FVIII-PCs were detected in the spleen but not in the BM. In addition, when splenocytes from inhibitor+ FVIII-KO mice were grafted into splenectomized immuno-deficient mice, inhibitor levels were significantly reduced in the serum. CONCLUSION: The spleen is the major site responsible for the expansion and retention of FVIII-PCs in the presence of high-titer inhibitors.

In vivo effect of rFVIII and rFVIIa in hemophilia A rats evaluated by the Tail Vein Transection Bleeding Model.

BACKGROUND: Preclinical bleeding models increase current hemophilia A (HA) knowledge and aid the development of new pharmacological treatments. There are several well-established mouse bleeding models, but limited options are available for rat models despite their high resemblance to human disease process. OBJECTIVE: To provide a comprehensive description of the tail vein transection (TVT) bleeding model in HA rats and examine the correlation between in vivo pharmacological efficacy and global hemostatic assays. METHODS: The TVT bleeding model was implemented in HA rats and used to perform dose-response studies with recombinant coagulation factors VIIa (rFVIIa) and VIII (rFVIII). After the TVT bleeding model, whole blood and plasma were collected from rats and evaluated with thrombin generation test (TGT) and rotational thromboelastometry (ROTEM). RESULTS: Using the TVT bleeding model, the potency of rFVIII and rFVIIa treatments in HA rats were assessed, and the pharmacological windows established for rFVIII (≤15 U/kg) and rFVIIa (≤2.7 mg/kg). ED50 was estimated to be 1.75 U/kg for rFVIII and 0.37 mg/kg for rFVIIa, whereas complete normalization was observed with 15 U/kg and 2.7 mg/kg respectively. Furthermore, responses to rFVIII and rFVIIa in the TGT and ROTEM assays strongly correlated to in vivo pharmacological efficacy. CONCLUSION: The TVT bleeding model in HA rats is a useful tool to assess the pharmacodynamic effects of hemostatic compounds in vivo, and strongly correlates to results obtained with TGT and ROTEM in HA rats, adding further value to the HA rat model in preclinical research.

Cost-utility analysis of emicizumab for the treatment of severe hemophilia A patients in Canada.

INTRODUCTION: EHL FVIII products and emicizumab provide clinicians with other prophylactic options for treating hemophilia A, however, it is unclear if emicizumab is a cost-saving option. The objective of this study is to estimate the health and economic effects of using prophylactic EHL FVIII, SHL FVIII, and emicizumab in severe haemophilia A patients. MATERIALS AND METHODS: A state-transition Markov model evaluated the cost-effectiveness of prophylactic SHL FVIII, EHL FVIII, and emicizumab in a cohort of 2-year-old male patients over a lifetime horizon in the form of a cost-utility analysis using a Canadian provincial ministry of health payer perspective. The transition probabilities, costs, and utilities were obtained from literature and the Canadian Bleeding Disorders Registry. Probabilistic sensitivity and scenario analyses were performed to test the robustness of the model. RESULTS: The base-case analysis, over a lifetime horizon, resulted in a total cost and utilities per person for SHL FVIII, EHL FVIII, and emicizumab of $27.2 million (M), $36.7 M, and $26.2 M, respectively, and 31.30, 31.16, and 31.61 quality-adjusted life years, respectively. Emicizumab treatment resulted in 29 and 16 less bleeds in a lifetime compared to SHL FVIII and EHL FVIII, respectively. Probabilistic sensitivity analysis showed that emicizumab was cost-saving 100% of the time compared to SHL FVIII and EHL FVIII. CONCLUSION: The cost-utility analysis showed that emicizumab is more effective and may be less costly than FVIII for Canadian haemophilia A patients, conditional on drug cost assumptions. Our model indicates that emicizumab may be a potentially favourable treatment option for minimising healthcare costs and providing higher effectiveness.

Area under the curve: Comparing the value of factor VIII replacement therapies in haemophilia A.

INTRODUCTION: In factor VIII (FVIII) prophylaxis for haemophilia A, cost comparisons have used price per international unit (IU) based on the once reasonable assumption of equivalent outcome per IU. Now, with several extended half-life (EHL) products available, new outcome-oriented ways to compare products are needed. Area under the curve (AUC) quantifies FVIII levels over time after infusion providing comparable data. AIM: To develop a decision analytical model for making indirect comparisons of FVIII replacement products based on AUC. METHODS: A literature search identified 11 crossover studies with relevant pharmacokinetic data. A common comparator FVIII level curve was calculated using pooled data from selected studies. Absolute curves for other products were estimated based on relative differences to the common comparator (% difference vs the anchor). Three scenarios were investigated: (1) Kogenate® versus Kovaltry® and Jivi® ; (2) Advate® versus Elocta® , NovoEight® , Kovaltry, Adynovate® , Afstyla® , and ReFacto® ; and (3) Jivi versus Elocta, Adynovate, and Kogenate. Sensitivity analyses investigated effects of assay type and dose. RESULTS: In scenario 1, Jivi (+50%) and Kovaltry (+14%) showed larger AUCs versus Kogenate. In scenario 2, EHL products, Elocta and Adynovate, had the largest AUC (+64% and +58%, respectively) versus Advate. Compared with all other products in scenario 3, Jivi had the largest AUC by +13%-28%. CONCLUSION: This analysis concludes that EHL products differ in relative AUC, have a larger AUC compared with standard half-life, and thus, different FVIII levels over time after infusion. This model may aid decision makers in the absence of head-to-head data.

Biological activity of a new recombinant human coagulation factor VIII and its efficacy in a small animal model.

Deficiency in human coagulation factor VIII (FVIII) causes hemophilia A (HA). Patients with HA may suffer from spontaneous bleeding, which can be life-threatening. Recombinant FVIII (rFVIII) is an established treatment and prevention agent for bleeding in patients with HA. Human plasma-derived FVIII (pdFVIII), commonly used in clinical practice, is relatively difficult to prepare. In this study, we developed a novel B-domain-deleted rFVIII, produced and formulated without the use of animal or human serum-derived components. rFVIII promoted the generation of activated factor X and downstream thrombin, and, similar to that of other available FVIII preparations, its activity was inhibited by FVIII inhibitors. In addition, rFVIII has ideal binding affinity to human von Willebrand factor. Activated FVIII (FVIIIa) could be degraded by activated protein C and lose its procoagulant activity. In vitro, commercially available recombinant FVIII (Xyntha) and pdFVIII were used as controls, and there were no statistical differences between rFVIII and commercial FVIII preparations, which demonstrates the satisfactory efficacy and potency of rFVIII. In vivo, HA mice showed that infusion of rFVIII rapidly corrected activated partial thromboplastin time, similar to Xyntha. Moreover, different batches of rFVIII were comparable. Overall, our results demonstrate the potential of rFVIII as an effective strategy for the treatment of FVIII deficiency.

Anti-idiotype monoclonal antibodies against emicizumab enable accurate procoagulant and anticoagulant assays, irrespective of the test base, in the presence of emicizumab.

INTRODUCTION: Emicizumab markedly shortens the activated partial thromboplastin time (aPTT), resulting in inaccurate measurements of procoagulant and anticoagulant factor activities. We have recently reported that mixtures of two different anti-idiotype monoclonal antibodies against emicizumab (anti-emicizumab-mAbs) allow measurement of factor (F)VIII activity (FVIII:C) and FVIII inhibitor in emicizumab-containing plasmas. It is unknown whether anti-emicizumab mAbs can work for other aPTT-based procoagulant and anticoagulant assays. AIM: To investigate whether anti-emicizumab mAbs were measured by all of the aPTT-based assays tested. METHODS: Two anti-emicizumab-mAbs (300 µg/mL each) were preincubated with emicizumab (200 µg/mL)-spiked FVIII-deficient plasma; we then measured FVIII:C, FIX:C, FXI:C, FXII:C, protein (P)C:C, PS:C, global PC-FV (aPTT-based), and prothrombin time (PT), diluted Russel's viper venom time (dRVVT), chromogenic-based FVIII:C, FIX:C and PC:C (non-aPTT-based). Emicizumab (100 µg/mL)-spiked haemophilia (H)A plasmas from patients (n = 23) were also measured. RESULTS: Emicizumab shortened the clotting time in all aPTT-based assays, resulting in high levels of FVIII:C, FIX:C, FXI:C and FXII:C; low levels of PC:C and PS:C; and false-positive results for activated PC resistance. The addition of anti-emicizumab-mAbs to emicizumab-added plasma restored all factors to the initial levels without emicizumab. Chromogenic FVIII:C measurement by human FIXa/FX was affected by emicizumab, but anti-emicizumab mAbs cancelled this effect. PT-based assays and dRVVT, chromogenic FIX:C and PC:C assays showed no effect with emicizumab. Twenty-three plasma samples from HA patients also showed similar patterns. CONCLUSION: Anti-emicizumab mAbs in vitro could cancel the effect of emicizumab, irrespective of the test base, resulting in accurate measurements of procoagulant and anticoagulant factor activity.

rFVIII-Fc in severe haemophilia A: The incentive switch in case of high risk of joint bleedings.

BACKGROUND: Efmoroctocog alfa, the first recombinant factor VIII fusion protein with extended half-life (rFVIII-Fc), has been hypothesized to lower FVIII consumption in patients with severe Haemophilia A (pwSHA), without reducing clinical efficacy. What about real life? METHOD: MOTHIF-II was a noninterventional, multicentre, before/after study, via the collection of retrospective data from July 2015 to June 2016 (called T1), and from July 2017 to June 2018 (called T2), in 7 French haemophilia treatment centres. We examined the prescriptions and dispensations of factor VIII and the Annual Bleeding Rate (ABR), in pwSHA without current inhibitors on prophylaxis, before and after the introduction of rFVIII-Fc. The data gathered from the BERHLINGO research database and from the French Healthcare claims database with a determinist pairing process based on the national unique identification number. RESULTS: A total of 156 pwSHA were included in the prescription cohort and 83 in the ABR cohort. For switched patients, the mean amounts of prescribed FVIII were significantly higher during T1 compared to T2 (4333 (2052) vs. 3921 (2029) IU/kg/year/patient, p: 0.028); a significant decrease in their ABR was also observed between T1 and T2 (6.3 (6.0) vs. 4.4 (5.4), p: 0.047). These patients had a more severe bleeding profile centred on haemarthrosis. CONCLUSION: The results are related to those of the pivotal clinical trials for the reduction in FVIII consumption following the switch to rFVIII-Fc, with a significant improvement in the haemorrhagic phenotype for pwSHA.

Clinical application of extended half-life factor VIII in children with severe haemophilia A.

INTRODUCTION: Only few studies have presented results from real-world clinical use of Extended Half-Life (EHL) products in children with haemophilia (CWH). AIM: To retrospectively examine real-life experience with EHL factor VIII products use in CWH A, comparing with clinical experience from standard half-life products (SHL). METHODS: A retrospective review of medical records of CWH A who have been prescribed EHL factor concentrates was conducted. All before/after comparisons were performed with the Wilcoxon matched-pairs signed-ranks test. RESULTS: Twenty-three children with severe haemophilia A were enrolled in the study (3-6 years old: n = 4, 7-12 years old: n = 7 and 13-18 years old: n = 12). Median length of time that patients were treated with EHL products was 78 weeks. Median dosing interval was significantly lengthened from 2.3 to 3.5 days after switching from SHL to EHL concentrates. Mean trough FVIII levels were significantly increased from 2.3% to 4.1% after treatment with EHL products. Also, CWH A had a reduction of mean annual bleeding rate (ABR) and mean annual joint bleeding rate (AJBR) from 1 and .8 to .3 and .2, respectively, following treatment with EHL concentrates (ABR: p = .02, AJBR: p = .05). However, after switching to factor EHL, actual FVIII consumption, including bleeds, was significantly increased from 94 IU/kg/week to 118 IU/kg/week in CWH A. There was no inhibitor development. CONCLUSION: This study demonstrates the successful transition of 23 CWH A from SHL to EHL factor concentrates.

MFGE8 decreased neuronal apoptosis and neuroinflammation to ameliorate early brain injury induced by subarachnoid hemorrhage through the inhibition of HMGB1

AIM: Both MFGE8 and HMGB1 were vital players for aneurysmal subarachnoid hemorrhage. However, whether HMGB1 was served as the downstream target of MFGE8 was unknown. To test this new mechanism, we performed the SAH model in rats. METHOD: All treatments were injected intraventricularly into the right lateral ventricles. SAH grade, brain water content, and neurological function scores were evaluated. HMGB1 expression was studied by double immunofluorescence staining. HE and Nissl's staining were performed to observe the pathological change. Inflammatory factors were measured by ELISA method. RESULTS: High expression of MFGE8 could improve neurological function and reduce the brain edema and pro-inflammatory factors. Injection of rhMFGE8 inhibited HMGB1. To further verify the regulation of MFGE8 in HMGB1, we used rhHMGB1 and glycyrrhizin, and the results indicated MFGE8 produced excellent effect on SAH rats via inhibiting HMGB1. CONCLUSION: In a word, MFGE8 improved EBI caused by SAH, depending on HMGB1 that was the potential mechanism.

An Update on Laboratory Diagnostics in Haemophilia A and B.

Haemophilia A (HA) and B (HB) are X-linked hereditary bleeding disorders caused by lack of activity of coagulation factors VIII (FVIII) or IX (FIX), respectively. Besides conventional products, modern replacement therapies include FVIII or FIX concentrates with an extended half-life (EHL-FVIII/FIX). Two main strategies for measuring plasma FVIII or FIX activity are applied: the one-stage clotting assay (OSCA) and the chromogenic substrate assay (CSA), both calibrated against plasma (FVIII/FIX) standards. Due to the structural modifications of EHL-FVIII/FIX, reagent-dependent assay discrepancies have been described when measuring the activity of these molecules. Assay discrepancies have also been observed in FVIII/FIX gene therapy approaches. On the other hand, nonfactor replacement by the bispecific antibody emicizumab, a FVIIIa-mimicking molecule, artificially shortens activated partial thromboplastin time-based clotting times, making standard OSCAs inapplicable for analysis of samples from patients treated with this drug. In this review, we aim to give an overview on both, the currently applied and future therapies in HA and HB with or without inhibitors and corresponding test systems suitable for accompanying diagnostics.