Prevention and Management of Bleeding Episodes in Children with Hemophilia

Design of a Real-World Observational Study in Previously Untreated and Minimally Treated Hemophilia A Patients: Protect-NOW

Background  The efficacy, safety, and immunogenicity of each of Octapharma's factor VIII (FVIII) products, Nuwiq, octanate, and wilate, have been investigated in previously untreated patients (PUPs) with severe hemophilia A in prospective clinical trials. The aim of the Protect-NOW study is to evaluate the effectiveness, safety, and utilization patterns of Nuwiq, octanate, and wilate in PUPs and minimally treated patients (MTPs; <5 exposure days [EDs] to FVIII concentrates or other blood products containing FVIII) with severe hemophilia A in a real-world setting. Real-world data provide valuable information that complement data obtained from interventional clinical trials. Methods  Protect-NOW (ClinicalTrials.gov identifier: NCT03695978; ISRCTN identifier: 11492145) is a real-world study in PUPs and MTPs treated with either the human cell line-derived recombinant FVIII Nuwiq (simoctocog alfa) or a plasma-derived FVIII concentrate containing von Willebrand factor (octanate or wilate). It is a prospective and (partly) retrospective, observational, international, noncontrolled, noninterventional study. A total of 140 PUPs and MTPs with severe hemophilia A will be enrolled across around 50 specialized centers worldwide and followed for either 100 EDs or a maximum period of 3 years from ED1. The primary objectives are to assess effectiveness in the prevention and treatment of bleeding episodes and overall safety, including inhibitor development. The secondary objectives are to assess utilization patterns (including dosage and frequency of administration) and the effectiveness in surgical prophylaxis. Conclusions  The Protect-NOW study will provide information on the treatment of PUPs and MTPs in routine clinical practice, which will help guide clinical decision making for treating these patients in the future.

Design of an international investigator-initiated study on MOdern Treatment of Inhibitor-positiVe pATiEnts with haemophilia A (MOTIVATE)

Background:

Inhibitor development is the most serious treatment-related complication of replacement coagulation factor VIII (FVIII) therapy for patients with haemophilia A. Immune tolerance induction (ITI), which involves intensive and prolonged treatment with plasma-derived or recombinant FVIII, is the only clinically proven strategy for eradication of inhibitors. The bispecific antibody emicizumab is approved for use in patients with and without inhibitors to prevent bleeding but does not eliminate inhibitors. MOTIVATE (www.motivate-study.com) aims to capture different approaches to the treatment and management of patients with haemophilia A and inhibitors, document current ITI approaches from real-world clinical experience, and evaluate the efficacy and safety of ITI, emicizumab prophylaxis and ITI with emicizumab prophylaxis.

Methods:

The investigator-initiated MOTIVATE study [ClinicalTrials.gov identifier: NCT04023019; EudraCT 2019-003427-38] will investigate in real-life clinical practice the management of patients with haemophilia A of any severity who have developed inhibitors to FVIII. All treatment is at the investigator’s discretion. The following treatment approaches will be evaluated: Group 1 – ITI with Nuwiq^®, octanate^® or wilate^® and aPCC/rFVIIa if needed to treat bleeding episodes (BEs) or during surgery or for prophylaxis; Group 2 – ITI with Nuwiq^®, octanate^® or wilate^® and emicizumab prophylaxis and aPCC/rFVIIa if needed to treat BEs or during surgery; Group 3 – routine prophylaxis with emicizumab, aPCC or rFVIIa without ITI and aPCC/rFVIIa if needed to treat BEs or during surgery. Patients will not be randomised to a treatment group and may change groups during the study.

Conclusions:

It is planned to enrol 120 patients who will be followed for up to 5 years. Optional sub-studies will explore factors that may influence ITI results as well as the impact of different treatment approaches on important aspects of patient health, including joint and bone health and the risk of thrombotic events.

Current therapeutic approaches in the management of hemophilia-a consensus view by the Romanian Society of Hematology

Hemophilia A (HA) and hemophilia B (HB) are rare disorders, being caused by the total lack or under-expression of two factors from the coagulation cascade coded by genes of the X chromosome. Thus, in hemophilic patients, the blood does not clot properly. This results in spontaneous bleeding episodes after an injury or surgical intervention. A patient-centered regimen is considered optimal. Age, pharmacokinetics, bleeding phenotype, joint status, adherence, physical activity, personal goals are all factors that should be considered when individualizing therapy. In the past 10 years, many innovations in the diagnostic and treatment options were presented as being either approved or in development, thus helping clinicians to improve the standard-of-care for patients with hemophilia. Recombinant factors still remain the standard of care in hemophilia, however they pose a challenge to treatment adherence because they have short half-life, which where the extended half-life (EHL) factors come with the solution, increasing the half-life to 96 hours. Gene therapies have a promising future with proven beneficial effects in clinical trials. We present and critically analyze in the current manuscript the pros and cons of all the major discoveries in the diagnosis and treatment of HA and HB, as well as identify key areas of hemophilia research where improvements are needed.

Recombinant Factor VIII Fc Fusion Protein (rFVIIIFc) in Real Life: One-Year Clinical and Economic Outcomes

Background

Recombinant factor VIII Fc fusion protein (rFVIIIFc) is the first extended half-life (EHL) recombinant clotting factor with marketing authorization; it has been available in France since October 2016. However, data and literature about rFVIIIFc in clinical practice are scarce.

Objective

We propose a 1-year clinical and economic outcome evaluation in patients with hemophilia A taking into consideration treatment adherence.

Patients and methods

We reviewed the diaries of all patients treated with rFVIIIFc at Marseille Hemophilia Center for 1 year. All the data were related to the patients’ infusion (i.e., annual number of infusions, weekly dose/kg, and annual consumption) and bleeding reports. The clotting factor costs were considered, whereas additional costs (e.g., infusion devices and nurse intervention) were neglected.

Results

A total of 34 patients were evaluated. Their median age was 18 years (IQR = 18). Treatment adherence was observed in 62% for FVIII and 66% for rFVIIIFc. The analysis revealed a negligible decrease in the annual clotting factor consumption following the switch (− 2%, p = 0.7339). These data were combined with a significant reduction in the annual number of infusion (− 22.5%, median = 138.5, IQR = 65.8 for FVIII; median = 105, IQR = 24 for rFVIIIFc, p < 0.0001) and bleeding (− 50%, median = 5, IQR = 7.5 for FVIII; median = 1, IQR = 4 for rFVIIIFc, p < 0.0001). With regard to the cost, a decreasing trend was observed (− 8%, p = 0.1300).

Conclusion

The analysis in a real-life setting revealed that the input of switches toward rFVIIIFc in different treatment (age of patients and regimen) patterns seems to corroborate previous studies. The results suggest that switches have a beneficial effect in terms of efficacy, clotting factor consumption, and cost.

Hemophilia A ameliorated in mice by CRISPR-based in vivo genome editing of human Factor VIII

Hemophilia A is a monogenic disease with a blood clotting factor VIII (FVIII) deficiency caused by mutation in the factor VIII (F8) gene. Current and emerging treatments such as FVIII protein injection and gene therapies via AAV-delivered F8 transgene in an episome are costly and nonpermanent. Here, we describe a CRISPR/Cas9-based in vivo genome editing method, combined with non-homologous end joining, enabling permanent chromosomal integration of a modified human B domain deleted-F8 (BDD-F8) at the albumin (Alb) locus in liver cells. To test the approach in mice, C57BL/6 mice received tail vein injections of two vectors, AAV8-SaCas9-gRNA, targeting Alb intron 13, and AAV8-BDD-F8. This resulted in BDD-F8 insertion at the Alb locus and FVIII protein expression in the liver of vector-, but not vehicle-, treated mice. Using this approach in hemophilic mice, BDD-F8 was expressed in liver cells as functional human FVIII, leading to increased plasma levels of FVIII and restoration of blood clotting properties in a dose-dependent manor for at least 7 months, with no detectable liver toxicity or meaningful off-target effects. Based on these findings, our BDD-F8 genome editing approach may offer an efficacious, long-term and safe treatment for patients with hemophilia A.

How I approach: Previously untreated patients with severe congenital hemophilia A

Previously untreated patients with severe hemophilia A are a vulnerable population at risk for severe bleeding which is currently managed with exogenous clotting factor replacement. The primary burden of current treatment is high-titer inhibitor development. Evolving data on current treatment products as well as emerging therapeutics may inform treatment decisions to prevent bleeding and inhibitor formation. Considerations for diagnosis, education, and shared decision-making related to product choice and treatment regimen are discussed.