Design of a prospective observational study on the effectiveness and real-world usage of recombinant factor VIII Fc (rFVIIIFc) compared with conventional products in haemophilia A: the A-SURE study

Interim analyses of the multinational real-world prospective cohort HEM-POWR study evaluating the effectiveness and safety of damoctocog alfa pegol in patients with hemophilia A

OBJECTIVES

To assess effectiveness and safety of damoctocog alfa pegol in interim analyses of the ongoing real-world hemophilia A HEM-POWR study.

METHODS

HEM-POWR (NCT03932201) is a multinational Phase 4 prospective observational study. The primary objective was annualized bleeding rate (ABR) in previously treated patients (PTPs) with hemophilia A. Secondary objectives included adverse events and number of affected joints.

RESULTS

At data cut-off (August 17, 2022), the safety analysis set included 268 patients and the full analysis set (FAS) included 161 patients. The most common dosing regimen during observation period was prophylaxis (FAS = 158/161, 98.1%) every 3-4 days (twice weekly; FAS = 78/158, 49.4%) and a median (min, max) infusion dose of 37.5 (10, 72) IU/kg. PTPs receiving prophylactic damoctocog alfa pegol have fewer infusions compared with prior treatment. Median total ABR (Q1, Q3) was 0.0 (0.0, 1.8) and mean total ABR (SD) was 2.4 (8.2). The proportion of patients with no affected joints increased between initial visit and follow-up. No FVIII inhibitors, treatment-related adverse events, or deaths were reported.

CONCLUSIONS

Damoctocog alfa pegol shows effectiveness and acceptable safety, as well as consistent utilization, in real-world PTPs with hemophilia A, including in patients with non-severe hemophilia and those with a history of inhibitors. Please see video for a summary of this study.

A survey of physicians' treatment switching practice in people on long-term prophylaxis for hemophilia in five European countries

OBJECTIVE

Recombinant factor VIII and factor IX Fc fusion proteins (rFVIIIFc and rFIXFc) were developed with an extended half-life (EHL) to improve the management of people with hemophilia A (PwHA) and B (PwHB), respectively.

METHODS

This survey gathered physician-reported treatment decisions and physician views on outcomes in PwHA or PwHB who switched to rFVIIIFc or rFIXFc in the 12 months prior to study completion.

RESULTS

Physicians (N = 37) considered bleeds, pharmacokinetic parameters, joint health and adherence the most important factors to assess both in routine care and when deciding to switch to an EHL therapy. In the 12 months prior to study completion, 37 physicians switched 113 PwHA to rFVIIIFc and 25 physicians switched 36 PwHB to rFIXFc. Most PwH (>90%) had moderate or severe hemophilia and many (>60%) switched within 6 months of the survey. The main reason for switching PwHA to rFVIIIFc was to allow fewer injections (49%), while the main reason for switching PwHB to rFIXFc was the product becoming available for use (36%). Overall, 96% of PwHA and 89% of PwHB who were switched remained on these EHL products at the time of survey. Mean total weekly dose, injection frequency and annualized bleeding rate were reported to have reduced following switching.

CONCLUSION

This survey provides valuable insight into reasons for, and challenges to, the use of EHL products in clinical practice. Physicians perceived that switching to treatment with rFVIIIFc or rFIXFc can improve quality of life, treatment burden, disease control and adherence.

Clinical Utility of Subcutaneous Factor VIII Replacement Therapies in Hemophilia A: A Review of the Evidence

Hemophilia therapies have tremendously improved over the last decades with the development of prolonged half-life factor VIII (FVIII) and FIX concentrates, non-factor therapies, such as emicizumab, anti-TFPI antibodies or siRNA antithrombin and gene therapy. All of these new molecules significantly reduced the burden of the disease and improved the quality of life of patients with severe hemophilia. Emicizumab, a non-factor therapy, is currently the only subcutaneous molecule available for prophylactic treatment of severe hemophilia A. Because of the subcutaneous route of delivery and similar efficacy to FVIII replacement therapy, emicizumab has been rapidly adopted by patients and their families. This clinical observation emphasizes the relevance and need for the development of subcutaneous FVIII concentrates. Here, we report evidence-based advantages and interest in the subcutaneous route of administration for the treatment of hemophilia A and review the stages of development of the different subcutaneous FVIII molecules.

Efmoroctocog Alfa: A Review in Haemophilia A

Efmoroctocog alfa (Elocta®, Eloctate®, Eloctate™), an extended half-life (EHL) recombinant factor VIII (rFVIII)-Fc fusion protein, is approved for the treatment and prophylaxis of bleeding in patients with haemophilia A. The efficacy of efmoroctocog alfa in the prevention and treatment of bleeding in previously treated patients (PTPs) and previously untreated patients (PUPs) with severe haemophilia A has been demonstrated in phase III studies; this includes its use in the perioperative setting (in PTPs). Furthermore, the effectiveness of efmoroctocog alfa in clinical practice has been confirmed in numerous real-world studies; compared with conventional, standard half-life (SHL) FVIII products, prophylaxis with this EHL FVIII product achieved similar or reduced bleeding rates with fewer injections. Efmoroctocog alfa was generally well tolerated; inhibitors occurred in approximately one-third of PUPs in a phase III study. Efmoroctocog alfa is an established and effective EHL FVIII replacement therapy for the management of haemophilia A. Compared with SHL FVIII products, EHL FVIII products such as efmoroctocog alfa have the potential to optimise prophylactic outcomes by decreasing the burden of treatment or increasing the level of bleed protection.

Evaluation of the U.S. Adherence Questionnaires VERITAS-PRO and VERITAS-PRN for Use in Patients with Hemophilia in the German Healthcare System

AIM

 Since the U.S. adherence instruments VERITAS-PRO and VERITAS-PRN were developed in another healthcare system, we assumed that they are not appropriate for the German solidarity healthcare system. This study aims to evaluate the relevance of these instruments for the German healthcare system both by people with hemophilia (PWH) and by healthcare professionals (HCP).

METHODS

 A total of 50 PWH (23 adult hemophilia patients and 27 parents of children with hemophilia) and 25 HCP rated the relevance of the single items of the VERITAS-PRO and VERITAS-PRN on a 5-point Likert scale. In addition, both groups were asked to make suggestions for additional adherence questions. To investigate the relevance of these instruments, the accordance between the raters' evaluations was determined calculating the content validity index (CVI) and the content validity ratio (CVR) based on the critical values of the CVR (CVR_critical) to exclude chance and subjectivity.

RESULTS

 CVI (CVR) calculations revealed three (5) "very important" items for PWH and six (11) items for HCP. Only two (3) "very important" items were evaluated by both groups. Four domains were considered not important by both groups. Six PWH made 14 suggestions and 14 HCP made 24 suggestions for additional adherence questions.

CONCLUSION

 VERITAS-PRO and VERITAS-PRN have only very limited benefits for the German healthcare system. Since nonadherence has a great impact on the morbidity of PWH and on the costs for the healthcare system, there is a need for adherence instruments that are adapted to the specific needs of PWH in the German healthcare system.

Limited Generalizability of a Retrospective Chart Review Comparing 3 Recombinant FVIII Products for Hemophilia A Prophylaxis

DISCLOSURES

No funding supported the writing of this letter. Preblick, Ali, and DasMahapatra are employees and shareholders of Sanofi Genzyme. Gray is a postdoctoral fellow at Sanofi Genzyme and Rutgers University.