Non-replacement Therapies Research Articles

DNA base editing corrects common hemophilia A mutations and restores factor VIII expression in in vitro and ex vivo models

BackgroundReplacement and nonreplacement therapies effectively control bleeding in hemophilia A (HA) but imply lifelong interventions. Authorized gene addition therapy could provide a cure but still poses questions on durability. FVIIIgene correction would definitively restore factor (F)VIII production, as shown in animal models through nuclease-mediated homologous recombination (HR). However, low efficiency and potential off-target double-strand break still limit HR translatability. ObjectivesTo correct common model single point mutations leading to severe HA through the recently developed double-strand break/HR-independent base editing (BE) and prime editing (PE) approaches. MethodsScreening for efficacy of BE/PE systems in HEK293T cells transiently expressing FVIII variants and validation at DNA (sequencing) and protein (enzyme-linked immunosorbent assay; activated partial thromboplastin time) level in stable clones. Evaluation of rescue in engineered blood outgrowth endothelial cells by lentiviral-mediated delivery of BE. ResultsTransient assays identified the best-performing BE/PE systems for each variant, with the highest rescue of FVIII expression (up to 25% of wild-type recombinant FVIII) for the p.R2166∗ and p.R2228Q mutations. In stable clones, we demonstrated that the mutation reversion on DNA (∼24%) was consistent with the rescue of FVIII secretion and activity of 20% to 30%. The lentiviral-mediated delivery of the selected BE systems was attempted in engineered blood outgrowth endothelial cells harboring the p.R2166∗ and p.R2228Q variants, which led to an appreciable and dose-dependent rescue of secreted functional FVIII. ConclusionOverall data provide the first proof-of-concept for effective BE/PE-mediated correction of HA-causing mutations, which encourage studies in mouse models to develop a personalized cure for large cohorts of patients through a single intervention.

Riding the wave of change: Providing solid ground to support nursing with patient transitions to novel haemophilia therapies.

Haemophilia nursing practice has experienced a shift in the past decade, as the historic chief focus on factor infusions shifted to extended half-life products, bispecific antibody therapies and other non-replacement therapies. This evolution has driven a need for changes in nursing practice in many haemophilia treatment centres. This article intends to provide insights to the haemophilia nurse to champion practice changes at their haemophilia treatment centres. Two popular change theories, Lewin's three-step change model and Kotter's eight-step change model are discussed as a framework for haemophilia nurses to think, structure and be leaders in change. Examples of these models in practice could give guidance and examples to reflect on for haemophilia nurses needing to make changes in their practice settings. These models of change, alongside existing haemophilia nurse competencies and tools such as the shared decision-making tool from the World Federation of Hemophilia, can assist the nurse to be a capable change agent to usher in these new innovations.

Emicizumab prophylaxis in infants: Single-centre experience.

The hallmark of haemophilia A (HA) therapy is prophylaxis, aimed at spontaneous bleeding prevention. Emicizumab provides a viable alternative to intravenous factor replacement therapy. However, data on its use in infants are limited. This single-centre open arm prospective study reports on emicizumab prophylaxis in infants. We included severe HA patients under 1 year who started emicizumab prophylaxis since 2018, with longitudinal follow-up. The study collected data on demographics, clinical and laboratory variables, the occurrence of bleeding events, surgeries and treatment outcomes. Of the 27 enrolled infants, whose median age at prophylaxis initiation was 7 months, 24 primarily choose to start emicizumab therapy (3/27 switched from FVIII prophylaxis due to development of FVIII inhibitors). The median age for prophylaxis initiation decreased to 3 months in 2023. Following emicizumab initiation, the median calculated ABR decreased, and no intracranial haemorrhages were observed. Thrombin generation showed a significant improvement in peak height and endogenous thrombin potential at steady state after a loading period. Our study highlights a shift towards early prophylaxis in the era of non-replacement therapies. It underscores the need for continuous evaluation and refinement of treatment approaches, emphasizing personalized care and diligent monitoring in the evolving field of paediatric haemophilia care.

Hemophilia therapy in Italy: what the near future promises.

In Italy have materialized changes pertaining to the striking progress for replacement and non-replacement therapies in patients with hemophilia A and B. This editorial looks at further progress that is expected to occur in Italy as elsewhere with the approval of two gene therapies for the hemophilias, as well as the forthcoming approval and availability of a new factor VIII product with a very extended plasma half-life that can be administered no more frequently than once weekly.

Nonreplacement therapy for hemophilia in low-income countries: experience from a prospective study in Ivory Coast

BackgroundHemophilia management has fundamentally evolved over the last decades with the development of ground-breaking therapies. Because of their mode of action and biochemical properties, these innovative therapies that are available in developed countries could be readily implemented among people from low-income countries who are either not or inadequately treated with clotting factor concentrates (CFCs). ObjectivesWe aimed at evaluating the impact of prophylaxis with emicizumab, a bispecific monoclonal antibody mimicking the FVIII activity administered subcutaneously, among boys with severe hemophilia A (HA) from the Ivory Coast, where access to CFCs is limited to humanitarian aid. MethodsWe prospectively collected data on the implementation and outcomes of prophylaxis with emicizumab, in 33 Ivorian boys aged 2 to 13 years with severe HA (with and without inhibitors). Bleeds, CFC consumption, quality of life and satisfaction of the patients and their parents were assessed. ResultsOverall, 12 months after initiating emicizumab, a 99% reduction in bleeding rates was observed, with a raise from 18% to 100% of boys having zero spontaneous joint bleeds. Three boys required a single FVIII infusion following a traumatic bleed. Health-related quality of life measures significantly improved, and perception of treatment efficacy was positively rated in children and parents. Acceptance, tolerance, and adherence were excellent. Emicizumab was instrumental in successfully implementing uninterrupted, highly efficacious, and well-tolerated prophylaxis in 72% of the Ivorian children aged ≤ 13 years identified with severe hemophilia A. ConclusionThese data illustrate how innovative and disruptive nonreplacement therapies that are already accessible in developed countries could potentially provide equity in care by profoundly and rapidly modifying hemophilia burden with a magnified impact in low-income countries.

Leave no one behind: Optimal Care of all Patients with Haemophilia A.

Background: Haemophilia is an inherited bleeding disorder due to failure of throm-bin generation resulting from clotting factor deficiency. In haemophilia A, the de-ficient factor is Factor VIII due to mutations in the F8 gene. In the past several
 decades, we have seen an unprecedented evolution of therapies for managing hae-mophilia A (Mahlangu, 2022) . These have included blood and blood products to
 plasma-derived concentrate, recombinant concentrate, concentrate with improvedpharmacokinetics and, more recently, non-replacement therapies. Notwithstandingthese advances in treatments, patients with haemophilia A (PwHA) remain withseveral unmet needs.

Laying the foundations for gene therapy in Italy for patients with haemophilia A: A Delphi consensus study.

Current treatment for haemophilia A involves factor VIII replacement or non-replacement (emicizumab) therapies, neither of which permanently normalise factor VIII levels. Gene therapy using adeno-associated viral (AAV) vectors is an emerging long-term treatment strategy for people with severe haemophilia A (PwSHA) that is likely to be available for clinical use in the near future. This article proposes practical guidelines for the assessment, treatment, and follow-up of potential PwSHA candidates for AAV-based gene therapy. Using the Delphi method, a working group of Italian stakeholders with expertise in and knowledge of the care of adults with haemophilia A analysed literature for AAV-based gene therapy and drafted a list of statements that were circulated to a panel of Italian peers. During two rounds of voting, panel members voted on their agreement with each statement to reach a consensus. The Delphi process yielded 40 statements regarding haemophilia A gene therapy, across five topics: (1) organisational model; (2) multidisciplinary team; (3) patient engagement; (4) laboratory surveillance; and (5) patient follow-up and gene therapy outcomes. The consensus was reached for all 40 statements, with the second round of voting needed for five statements. Use of the hub-and-spoke organisational model and multidisciplinary teams are expected to optimise patient selection for gene therapy, as well as the management of dosing and patient follow-up, patient engagement, laboratory surveillance, and patient expectations regarding outcomes. This approach should allow the benefits of AAV-based gene therapy for haemophilia A to be maximised.

Erratum: A Cross-sectional Analysis of Treatment in PUPs in 2021 in Germany – First Data from the GEPHARD Study Group

Abstract Objectives Initial treatment in patients with haemophilia remains challenging. The choice of therapy, timing, dose and frequency have been and are still under intense debate. New treatment options like novel factor concentrates and non-factor therapies broaden the discussion. Design The German Paediatric Haemophilia Research Database (GEPHARD) is a multicentre prospective observational study including children and adolescents with haemophilia A or B (FVIII or FIX levels <25 IU/dL) in a German treatment centre after January 1st, 2017. A cross-sectional analysis was performed in June 2021. Results 249 children and adolescents from 22 participating centres in Germany were analysed in this cross-sectional analysis. 203 patients suffered from haemophilia A (PwHA) and 46 from haemophilia B (PwHB). The median age at diagnosis for Pw severe HA or HB was 6 or 2 months, the median age at analysis was 33 or 35 months for Pw severe HA or B, respectively. 117 Pw severe HA received treatment, including plasma derived concentrates (n = 43), standard recombinant concentrates (n = 23), extended half live concentrates (n = 33) and non-replacement therapies (n = 18). For Pw severe HB, plasma derived concentrates (n = 3), standard recombinant concentrates (n = 8) and extended half live concentrates (n = 14) were used. Current inhibitors were reported in 16 PwHA and 1 PwHB. Conclusions GEPHARD was successfully established as a national cohort for newly diagnosed PwH in Germany. Epidemiological and treatment data were presented. Longitudinal analyses of this growing cohort will allow to value treatment strategies and their outcome in the evolving treatment landscape.

Can T-cell and B-cell excision circles predict development of inhibitors in pediatric hemophilia A?

Hemophilia A (HA) therapy requires intravenous replacement infusions of factor (F) VIII concentrate. Inhibitors are high-affinity immunoglobulin G that are directed against FVIII and thereby render replacement therapy ineffective. This complication has significant prognostic implications. We aimed to examine the immune system involvement in inhibitor formation specifically T-cell excision circles (TRECs) and B-cell excision circles (KRECs), markers of new T and B cells, respectively, and examine them as surrogate markers for inhibitor formation. Blood samples were collected from 35 children with severe HA. Children were divided into two groups: with FVIII inhibitors and without FVIII inhibitors. TRECs and KRECs were measured in peripheral blood. A total of 11 patients with inhibitors and 24 without were evaluated. Children with inhibitors had higher levels of TRECs however not statistically significant (p = 0.085). CjKREC levels were higher in the inhibitor patients (p = 0.003). Moreover, the sj/cjKREC ratio was lower in the inhibitor patients (p = 0.015). Our findings may add to the notion that inhibitor formation is attributed to humoral immunity due to peripheral B-cell expansion and loss of peripheral tolerance. Improved knowledge regarding the involvement of the immune system in the formation of FVIII inhibitors will enable better therapy tailoring in the era of non-replacement therapies. The etiology of FVIII inhibitor formation is multifactorial, in which the immune system plays a pivotal role. Our findings may add to the notion that inhibitor formation is attributed to humoral immunity due to peripheral B-cell expansion and production of antibodies against FVIII. Improved knowledge regarding the involvement of the immune system in the development of FVIII inhibitors will enable the identification of patients prone to inhibitor development and better therapy tailoring in the new era of non-replacement therapies.

A preliminary application of a haemophilia value framework to emerging therapies in haemophilia.

Emergence of new therapies are anticipated to improve clinical outcomes and quality of life of persons with haemophilia. Challenges in conducting randomized clinical trials in rare diseases have resulted in a lack of direct head-to-head comparisons to support value-based decision-making between different treatments. We conducted a literature review for new and emerging haemophilia A and B therapies (extended half-life [EHL] replacement factor, non-replacement therapies [NRT], and gene therapies [GT]) to identify differentiating patient-centred outcomes defined previously in a haemophilia value framework. Since the literature included all publication types (e.g., surveys, modelling studies, commentaries/reviews), collected data were assigned level of evidence scores. Across different classes of therapies, bleeding was determined as the most frequently reported differentiating outcome, with EHL, NRT, and GT each demonstrating an advantage over comparator replacement therapies. EHL therapies for haemophilia A and B and NRT for haemophilia A showed good representation across Tier 1 outcomes (health status achieved/retained), while more publications were identified with Tier 2 (process of recovery) outcomes for NRT than EHL or GT. In Tier 3 (sustainability of health), frequency of breakthrough bleeds represented a differentiating outcome for EHL (both haemophilia A and B), NRT (haemophilia A only), and GT (haemophilia B only), whereas sustained good health was differentiating for most comparisons. We demonstrate the utility of the haemophilia value framework as a common core outcome set for effectively comparing therapies. Application of this framework will serve as a useful decision-making tool for patients, clinicians, and within health technology assessments. With the emergence of high-cost, paradigm changing treatments across multiple areas of medicine, we, the haemophilia community, need to be equipped to meet the growing demands for more rigorous evidence-based value assessments using the tools expected by assessors. The traditional access toolbox needs to evolve to meet the paradigm shift in treatment options. Value can no longer be defined by annualized bleed rates alone. To realize the full impact of new therapies, we need to utilize tools, such as a value framework, to organize evidence, identify data gaps, and assess patient-defined, meaningful outcomes across a multi-faceted dimension. The haemophilia value framework is an effective tool for organizing the available evidence and identifying gaps in the evidence. This can be used for assessing the value of emerging therapies in haemophilia utilizing data generated through randomized clinical trials and real world evidence generation. This is a call for incorporating the Value Framework into official submissions to authorities, as it captures a broader range of outcomes, including patient meaningful outcomes, in ways that better assess the potential benefits of new therapies.

Monitoring of new therapies for hemophilia.

Nonreplacement therapies, such as emicizumab (Hemlibra, Roche) and other myriad of molecules are still under study as concizumab (and other anti-TFPI) and fitusiran are transforming the quality of life and treatment of this group of patients. So far, laboratory monitorization has not been an obligate condition for the use of these novel therapies, though in some cases like their combination with bypassing agents to control breakthrough/surgical bleeds may seek for laboratory assays to ensure a well tolerated and effective utilization withing these special scenarios. In the next pages, application of global coagulation assays, for example, thrombinography or rotational thrombelastography will be referred looking to the works of some groups from around the world including our own experience.

Anti-Emicizumab Antibodies Do Not Cross-React with Mim8 in Vitro

BackgroundPatients with severe hemophilia A may develop inhibitors against factor VIII (FVIII) in around 30% of cases. Recently, the introduction of non-replacement therapies such as emicizumab, a FVIII-mimicking agent administered as a subcutaneous injection, has revolutionized the treatment of patients with inhibitors. However, although rarely, some patients may develop antibodies against this drug. If neutralizing, these antibodies interfere with the activity of the drug, making it ineffective. Mim8 (Novo Nordisk®) is a novel experimental FVIII-mimetic human bispecific antibody that has a similar function as emicizumab, by bridging activated FIX (FIXa) and FX to activate FX, although with a different molecular structure compared to emicizumab. It is currently in phase II clinical trial for subcutaneous treatment of patients with hemophilia A with or without FVIII inhibitors (1, 2).It is currently unknown whether the antibodies developed against emicizumab by patients with hemophilia A could cross-react with Mim8.AimOur aim was to study the cross-reactivity of anti-emicizumab antibodies developed by patients with hemophilia A against Mim8 with an in-house detection method.MethodsWe studied the serum of three patients who developed anti-emicizumab antibodies. Plasma from one patient with persistent inhibiting antibodies was collected both during the treatment (thus also containing emicizumab at steady-state levels) and two years after treatment discontinuation due to inefficacy (neutralizing persistent antibodies). Plasma from two patients who developed transient antibodies against emicizumab were also tested in the course of treatment with emicizumab (non-neutralizing transient antibodies). The plate was coated both with emicizumab and with Mim8 provided by the pharmaceutical companies for research purposes. Plasma samples, diluted 1/20, were loaded into the coated wells and incubated 90 min at 37°C. The cross-reactivity to Mim8 was evaluated also by using the affinity purified anti-emicizumab IgG, which was loaded at 5 ug/mL. A properly adapted ELISA method already described (3) was used as reference assay. Then, biotinylated-emicizumab (1.5 ug/mL) or biotinylated-Mim8 (at 2 and 4 ug/mL) were added and the plate incubated 1 hour at 37°C. Moreover, a competition test was performed by using a mixture of biotinylated-emicizumab (1.5 ug/mL) and an excess of Mim8 (at 4, 8 and 40 ug/mL) in the detection phase.ResultsThe Mim8 molecule - either alone, or matched with emicizumab - used both in the capture phase and in the detection phase did not bind to neither patient's plasma antibodies nor to anti-emicizumab purified IgG, which were instead revealed with the reference assay. The binding of the anti-emicizumab antibodies to biotinylated-emicizumab was not inhibited by the addition of Mim8, even at 40 ug/mL.ConclusionsOur in-house method showed that anti-emicizumab antibodies do not react with Mim8 in vitro. Observational studies to test whether Mim8 can be used safely in patients with anti-emicizumab antibodies are needed to confirm our findings in vivo as well.

Emerging drugs for hemophilia A: insights into phase II and III clinical trials

ABSTRACT Introduction Hemophilia is a lifelong, genetic-bleeding disorder, which inadequately treated results in permanent joint damage. It is characterized by spontaneous and trauma-related bleeding episodes. In the last 50 years, treatment has seen dramatic improvements which have improved the quality of life of persons with hemophilia. Areas covered This review will provide a summary of current pharmacological approaches for hemophilia A as well as discuss novel agents which are either approved recently or in phase II–III clinical trials, plasma-derived and recombinant factor VIII (FVIII) products, extended half-life FVIII products, bypassing agents and non-replacement therapies. Expert opinion Novel therapies are already changing the way that hemophilia A is managed, and as more new therapies get approved, there will be a revolution in the management of this serious condition. Clinicians will have both the opportunities as well as the challenges of incorporating such new technologies into clinical practice.

Nonfactor Therapies: New Approaches to Prophylactic Treatment of Haemophilia.

For several decades, the treatment of haemophilia has relied on factor replacement therapy, which restores haemostasis by replacing the missing coagulation factor. In recent years, novel alternative therapies for the treatment of haemophilia in patients with and without inhibitors have been developed. These emergent therapies promote haemostasis by mimicking coagulation factors or inhibiting natural anticoagulants. They provide a less invasive route of administration (i.e. subcutaneous) and some offer reduced frequency of dosing (i.e. every 2 weeks, monthly) compared with the majority of factor replacement therapies, and thus have the potential to simplify treatment, increase adherence and subsequently improve outcomes for patients. Their introduction has transformed the care of haemophilia patients with inhibitors to factor VIII, with similar expectation for haemophilia B patients with inhibitors. However, these therapies also come with several new challenges including their limitation to prophylactic treatment, the observed increased incidence of thrombosis, or their impact on the natural history of the disease and potential disruption of existing treatment guidelines like the use of immune tolerance induction. Moreover, questions remain regarding the long-term impact of non-replacement therapies on joint health as well as the optimal strategy to manage breakthrough bleeds in patients with inhibitors.

Clinical phenotype of severe and moderate haemophilia: Who should receive prophylaxis and what is the target trough level?

One of the most often stated tenets of haemophilia care is that prophylaxis converts a person from a severe to a moderate phenotype. In this review, we argue that this is not an accurate assumption and that people on prophylaxis predominantly have factor VIII/IX levels in the mild range. People with moderate haemophilia, who are treating with on-demand regimens, experience joint bleeds and often develop significant arthropathy. This is especially true for people with a baseline level of 1-3IU/dl, as first reported 55years ago, and confirmed in more recent studies. Evidence is emerging suggesting that people with severe haemophilia who are using prophylaxis have better musculoskeletal outcomes than people with moderate haemophilia treated episodically. The debate around the optimum trough level whilst on prophylaxis is ongoing. It is not appropriate to extrapolate information about baseline levels to recommendations about target trough levels on prophylaxis because these are different situations. Studies are emerging that support higher target trough levels than previously used, but in spite of this, the aim of achieving zero bleeds remains elusive with both factor replacement and non-replacement therapies. We recommend that people with moderate haemophilia, especially those with a baseline of 1-3IU/dl, should be offered prophylaxis based on the same criteria as people with severe haemophilia. Trough levels should be maintained above 3IU/dl or higher if a level of 3IU/dl does not control breakthrough bleeding and prophylaxis should be tailored to the bleeding phenotype. This advice is in line with recently published guidelines from the World Federation of Haemophilia and the UK Haemophilia Centre Doctors' Organisation.

Immune Responses to Plasma-Derived Versus Recombinant FVIII Products.

The most severe side effect of hemophilia treatment is the inhibitor development occurring in 30% of patients, during the earliest stages of treatment with factor (F)VIII concentrates. These catastrophic immune responses rapidly inactivate the infused FVIII, rendering the treatment ineffective. This complication is associated with a substantial morbidity and mortality. The risk factors involved in the onset of the inhibitors are both genetic and environmental. The source of FVIII products, i.e. plasma-derived or recombinant FVIII products, is considered one of the most relevant factors for inhibitor development. Numerous studies in the literature report conflicting data on the different immunogenicity of the products. The SIPPET randomized trial showed an increased in the inhibitor rate in patients using recombinant FVIII products than those receiving plasma-derived products in the first exposure days. The SIPPET randomized trial showed an increase in the inhibitor rate in patients using recombinant FVIII products compared to those treated with plasma-derived products in the first days of exposure. The potential increase in the immunogenicity of recombinant products can be attributed to several factors such as: the different post-translational modification in different cell lines, the presence of protein aggregates, and the role played by the chaperon protein of FVIII, the von Willebrand factor, which modulates the uptake of FVIII by antigen presenting cells (APCs). Furthermore, the presence of non-neutralizing antibodies against FVIII has shown to be in increased inhibitor development as demonstrated in a sub-analysis of the SIPPET study. In addition, the presence of the specific subclasses of the immunoglobulins may also be an important biomarker to indicate whether the inhibitor will evolve into a persistent neutralizing antibody or a transient one that would disappear without any specific treatment. Recently, the availability of novel non-replacement therapies as well as emicizumab, administered by weekly subcutaneous infusion, have significantly changed the quality of life of patients with inhibitors showing a considerable reduction of the annual bleeding rate and in most patients the absence of bleeding. Although, these novel drugs improve patients' quality of life, they do not abolish the need to infuse FVIII during acute bleeding or surgery. Therefore, the issue of immunogenicity against FVIII still remains an important side effect of hemophilia treatment.

Reducing Antithrombin in Plasma to Levels Observed in Fitusiran-Treated Patients Does Not Interfere with Coagulation Assays

Introduction: Fitusiran is being evaluated in phase 3 clinical studies as a once monthly subcutaneously administered RNA interference therapy designed to decrease endogenous expression of the anticoagulant antithrombin (AT). Reducing the anticoagulant potential of AT in the plasma of Hemophilia A and B patients, with or without inhibitors, restores the hemostatic balance and improves thrombin generation potential. Fitusiran and other non-Factor replacement molecules, such as emicizumab, use novel mechanisms to restore hemostasis. Consequently, some standard coagulation assays typically used to measure factor levels, such as the chromogenic, one-stage, and APTT assays have been shown to be affected by emicizumab. In order to assess the potential impact of fitusiran treatment on our ability to measure clotting factor activity in individuals with hemophilia A (HemA), we investigated the effect of decreased AT levels on standard coagulation laboratory assays. The following four assays were evaluated: one stage (OSA) and chromogenic (CSA) factor VIII (FVIII) activity assays, activated partial thromboplastin time (aPTT), and the prothrombin clotting time assay (PT). These assays are relevant to determine the FVIII plasma levels in patients dosed with FVIII replacement factors while treating potential breakthrough bleeds or undergoing surgery. Method and Results: Pooled human HemA plasma was used directly or after AT depletion using an affinity-based method to remove 95% AT activity, resulting in HemA plasma with 5% AT activity. Additional batches of HemA/AT levels were created by AT reconstitution to 10 and 20% AT plasma activity. Subsequently, the 4 HemA plasma pools (one with normal -100 %- AT and three with reduced levels of AT-5, 10, 20%) were prepared with FVIII spiked to 0, 5, 10, 20, 30, 50, and 100% . FVIII plasma activity was measured by OSA and CSA against Siemens normal standard plasma. Compared to FVIII plasma activity for all FVIII spikes in normal HemA plasma containing 100% AT, respective FVIII spikes in HemA/AT depleted plasma samples (5, 10, and 20% AT) did not show therapeutic significant effects of AT levels on measured FVIII activity by OSA and chromogenic FVIII activity assay. Additionally, we evaluated the effect of the various AT levels and FVIII spikes on clotting assays, aPTT and PT, among the HemA plasma with varying (5-100%) AT levels. AT level did not affect the aPTT for respective FVIII spikes in HemA and Hem/AT depleted plasma. Furthermore, no therapeutic relevant effect of ATIII and FVIII level was observed in PT values between HemA and Hem/AT depleted plasma. Conclusions: Our results demonstrate that a reduction of AT levels in plasma does not affect standard coagulation assays, suggesting these assays can be utilized to assess hemostasis and factor levels in individuals treated with fitusiran. The ability to monitor FVIII levels in patients treated with non-replacement therapies is important as these patients require factor to treat breakthrough bleeds and during some surgeries. Disclosures Wang: sanofi: Current Employment, Current equity holder in publicly-traded company. Kattula:Sanofi: Current Employment, Current equity holder in publicly-traded company. Ismail:Sanofi: Current Employment, Current equity holder in publicly-traded company. Leksa:Sanofi: Current Employment, Current equity holder in publicly-traded company. van Der Flier:sanofi: Current Employment, Current equity holder in publicly-traded company. Salas:sanofi: Current Employment, Current equity holder in publicly-traded company.

Annual Bleeding Rates: Pitfalls of Clinical Trial Outcomes in Hemophilia Patients.

Emerging treatment options for hemophilia, including gene therapy, modified factor products, antibody‐based products, and other nonreplacement therapies, are in development or on their way to marketing authorization. For proof of efficacy, annual bleeding rates (ABRs) have become an increasingly important endpoint in hemophilia trials. We hypothesized that ABR analyses differ substantially between and within medicinal product classes and that the ABR observation period constitutes a major bias. For ABR characterization, an internal factor VIII (FVIII) treatment database has been built based on confidential clinical trial data submitted to the Paul‐Ehrlich‐Institut (PEI). Furthermore, anonymized data from 46 trial protocols submitted for review to the PEI were analyzed (FVIII replacement, n = 27; antibody‐based, n = 12; and gene therapy, n = 7) for methodology. Definitions of bleeding episodes and ABR observational periods differed substantially in clinical trials. In the initial observation phase, individual ABRs of patients, treated prophylactically for 1 year, vary by about 40% (P < 0.001), which finally led to a significant reduction of the ABR group mean by 20% (P < 0.05). Furthermore, the high variance in ABRs constitutes a major challenge in statistical analyses. In conclusion, considerable heterogeneity and bias in the ABR estimation in clinical trials was identified, which makes it substantially more difficult to compare the efficacy of different treatment regimens and products. Thus, awareness of the important pitfalls when using ABR as a clinical outcome is needed in the evaluation of hemophilia therapies for patients, physicians, regulators, and health technology assessment agencies.

Kreuth V initiative: European consensus proposals for treatment of hemophilia using standard products, extended half-life coagulation factor concentrates and non-replacement therapies.

This report contains the updated consensus recommendations for optimal hemophilia care produced in 2019 by three Working Groups (WG) on behalf of the European Directorate for Quality of Medicines and Healthcare in the frame of the Kreuth V Initiative. WG1 recommended access to prophylaxis for all patients, the achievement of plasma factor trough levels of at least 3-5% when extended half-life factor VIII (FVIII) and FIX products are used, a personalized treatment regimen, and a choice of chromogenic assays for treatment monitoring. It was also emphasized that innovative therapies should be supervised by hemophilia comprehensive care centers. WG2 recommended mandatory collection of postmarketing data to assure the long-term safety and efficacy of new hemophilia therapies, the establishment of national patient registries including the core data recommended by the European Medicines Agency and the International Society on Thrombosis and Haemostasis, with adequate support under public control, and greater collaboration to facilitate a comprehensive data evaluation throughout Europe. WG3 discussed methodological aspects of hemophilia care in the context of access decisions, particularly for innovative therapies, and recommended that clinical studies should be designed to provide the quality of evidence needed by regulatory authorities, HTA bodies and healthcare providers. The dialogue between all stakeholders in hemophilia care and patient organizations should be fostered to implement these recommendations.

Evaluation of stem cell therapies for amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder for which treatment consists mainly of palliative care. Two drugs are currently widely available in the US for treatment, Riluzole and Edaravone, which can mildly attenuate motor decline and slightly prolong survival. Stem cells are currently being explored as treatment possibilities because of their ability to differentiate to healthy motor neurons and astrocytes especially, which are thought to be a major source of the neuronal damage by engaging in a positive feedback loop of neuroinflammation. Various stem cell types are also known to secrete neurotrophic factors which can promote healthy astrocyte function and mediate axonal regeneration and repair. This leads to two broad classifications of stem cell therapies: Replacement and Non-replacement. Replacement therapies tend to use neural stem cells to supplant the host’s diseased astrocytes and create a healthy environment. Motor replacement is less feasible due to the distance they need to grow to reach the neuromuscular junction and difficulties of integration. Non-replacement therapies tend to use bone marrow mesenchymal stromal cells and tend to focus on immunomodulation to reduce damage to the motor neurons. Results from animal trials and phase I/II clinical trials show that both types of treatment using stem cells such as neural stem cells, bone marrow mesenchymal stem cells, dental pulp, and adipose derived stem cells can reduce neuroinflammation and motor neuron degradation, attenuate motor decline, and in many cases prolong survival. Future studies should look to the application of combined replacement and non-replacement strategies using both neural stem cells and mesenchymal stem cells to achieve an even greater level of neuroprotection.