Bleeding outcomes and factor utilization after switching to an extended half-life product for prophylaxis in haemophilia A in Austria

An observational study of haemophilia A patients without inhibitors using the French national claims (SNDS) database

OBJECTIVES

To describe clinical characteristics, factor consumption, and events of interest in patients with haemophilia A without inhibitors receiving prophylaxis in France, and the clinical impact of switching to Elocta® in this population.

METHODS

This retrospective, observational study using the Système National des Données de Santé database, analysed data from patients with haemophilia A without inhibitors using prophylactic factor VIII (FVIII) replacement therapy during 2016-2019. Clinical characteristics, treatment patterns and switches, factor consumption, and rate of events of interest were determined. In a sub-cohort of patients treated with Elocta®, clinical characteristics, factor consumption, and rate of events of interest before and after switching to Elocta® were compared.

RESULTS

For 545 patients, with mean age (standard deviation [SD]) 25.4 (17.8) years, Elocta® was the most used treatment. Bleeding events and articular non-bleeding events leading to hospitalization occurred in 15.4% and 13.9% of patients, respectively, and 9.9% of patients had surgeries or procedures related to haemophilic arthropathy. The mean (SD) FVIII product consumption was 344 (93) IU/kg/month for extended half-life treatment, and 331 (98) IU/kg/month for standard half-life products. For the sub-cohort of 146 patients, bleeding events (SD) decreased from 0.32 (2.2) to 0.09 (0.42) events/patient/year (p = 0.227) after switching to Elocta®. There was no statistically significant difference in rates of factor consumption or articular non-bleeding events before and after initiation of Elocta®.

CONCLUSION

This study provides real-world insights that advance the understanding of treatment patterns and events of interest in patients with haemophilia A on prophylactic regimens in France.

A post hoc analysis of PROTECT VIII kids assessing long-term efficacy and safety of damoctocog alfa pegol in adolescents with severe haemophilia A

INTRODUCTION

The safety and efficacy of the extended half-life factor VIII (FVIII) product damoctocog alfa pegol (BAY 94-9027, Jivi®) has been demonstrated in the PROTECT VIII Kids study (NCT01775618), where male previously-treated patients (PTPs) aged <12 years old with severe haemophilia A and ≥ 50 exposure days (EDs) were treated prophylactically. The PROTECT VIII Kids extension study assessed the long-term safety and efficacy of damoctocog alfa pegol in the same population.

AIM

To evaluate the long-term impact of damoctocog alfa pegol in a post hoc subgroup analysis of adolescent patients in the PROTECT VIII Kids study and its extension from 12th birthday onwards.

METHODS

The current analysis included PTPs aged ≥12 years old, who remained in the extension for ≥6 months following their 12th birthday. The observation period was defined as the time from 12th birthday to the end of the extension period; all data from this birthday were included whether in the main study or extension phase. The main efficacy variable was annualised bleeding rate (ABR) and the main safety variable was the frequency of inhibitor development.

RESULTS

This subgroup analysis comprised 25 patients. Median observation time after 12th birthday was 3.2 years. Median total/joint/spontaneous ABRs in the observation period were 1.7/0.7/0.3, respectively. Safety findings were consistent with those reported for the overall study population; no confirmed FVIII inhibitors or anti-drug antibodies were reported.

CONCLUSIONS

Damoctocog alfa pegol is efficacious with a favourable safety profile in adolescents with haemophilia A, supporting its long-term use in children and adolescents.

Long-term outcomes with emicizumab in hemophilia A without inhibitors: results from the HAVEN 3 and 4 studies

Background

Emicizumab, a bispecific monoclonal antibody, bridges activated factor (F) IX and FX, mimicking the function of missing or deficient activated FVIII in people with hemophilia A (HA).

Objectives

To evaluate the long-term efficacy and safety of emicizumab prophylaxis in people with HA without FVIII inhibitors in the HAVEN 3 and 4 studies.

Methods

HAVEN 3 and 4 were phase 3 open-label studies. Participants received emicizumab maintenance doses of 1.5 mg/kg every week or 3 mg/kg every 2 weeks (HAVEN 3), or 6 mg/kg every 4 weeks (HAVEN 4). Long-term efficacy and safety were assessed.

Results

A total of 151 and 40 individuals without FVIII inhibitors received emicizumab in HAVEN 3 and 4, respectively. At the last patient, last visit dates (May 12, 2022 [HAVEN 3] and June 29, 2022 [HAVEN 4]), the median (range) duration of emicizumab exposure across the 2 studies was 248.1 (6.1-287.1) weeks. The mean (95% CI) annualized bleed rate for treated bleeds was 2.0 (0.23-7.15) for weeks 1 to 24, decreasing to 0.9 (0.01-5.28) by weeks 217 to 240. Overall, 188 (98.4%) participants experienced ≥1 adverse event (AE), with 185 treatment-related AEs in 71 (37.2%) participants. Forty-four (23.0%) participants reported a serious AE. Two thromboembolic events were reported, which were deemed unrelated to emicizumab by the investigator. No thrombotic microangiopathies were reported.

Conclusion

With nearly 5 years of emicizumab exposure across the HAVEN 3 and 4 studies in people with HA without inhibitors, these data indicate continued bleed control with no new safety signals observed during long-term follow-up.

Evaluation of treatment and outcome for patients with haemophilia A and haemophilia B on extended half-life (EHL) factor products: A 12-month data analysis

INTRODUCTION

Extended half-life (EHL) factor VIII and IX concentrates as prophylaxis against bleeds have been available to selected persons with haemophilia (PWH) in Australia since March 2018. Preliminary analysis of switching to EHL demonstrated increased treatment adherence, fewer injections and improved bleeding outcomes.

AIMS

To characterise clinical practices regarding the use of EHL in Australia, to further evaluate treatment regimens and bleeding outcomes, and to analyse the influence of EHL product pharmacokinetics on clinical decision-making.

METHODS

A national, retrospective study was conducted using the Australian Bleeding Disorders Registry (ABDR). Patients on EHL products during the entire 2019 calendar year were included for analysis.

RESULTS

A complete and validated dataset of 174 PWH was analysed, 115 Haemophilia A (HA) and 59 Haemophilia B (HB). Adherence to EHL therapy was 85.7% in HA and 87.2% in HB. About 63.5% of HA and 64.4% of HB PWH reported zero spontaneous bleeds over 12months. Ankles were the most frequent spontaneous bleed site. Approximately one-third patients underwent dose adjustments, with most frequent reasons being pharmacokinetics, body weight change and breakthrough bleeds. About 19.5% of PWH had target joint history, with spontaneous bleeds reported in 58% of that cohort on EHL. Multivariate regression showed significant impact of non-adherence, target joint history and short half-life on spontaneous bleeds in the HA cohort; however only short half-life had significant impact in the HB cohort.

CONCLUSION

EHL usage in Australia shows excellent treatment adherence and bleeding outcomes. This study affirms the use and value of widely available population-based pharmacokinetics as a clinical tool.

Real-world evidence on efmoroctocog alfa in patients with haemophilia A: A systematic literature review of treatment experience in Europe

INTRODUCTION

The real-world effectiveness of the efmoroctocog alfa (recombinant FVIII Fc fusion protein, a rFVIIIFc) has been investigated in numerous studies, however, currently, there exists no comprehensive collection of the existing real-world evidence (RWE) on the performance of prophylactic use of rFVIIIFc.

AIM

The aims of this systematic literature study were to identify, review, evaluate and collate the RWE of prophylactic rFVIIIFc for patients with haemophilia A reported in Europe.

METHODS

We searched Medline and Embase from 2014 to February 2022 to identify publications reporting the effectiveness of rFVIIIFc in patients with haemophilia A. The outcomes of interest were annualised bleeding rates (ABR, AjBR, AsBR), injection frequency, factor consumption, adherence, development of inhibitors and quality-of-life measures.

RESULTS

46 eligible publications (eight full-text articles) were included. rFVIIIFc showed a low ABR in patients with haemophilia A. Studies assessing treatment switching from a standard half-life (SHL) treatment to rFVIIIFc found that the ABR and consumption were reduced in most patients. Studies assessing rFVIIIFc effectiveness reported a median ABR between 0.0 and 2.0 with median injections per week ranging between 1.8 and 2.4 and median doses between 60 and 105 IU/kg/week. Of the studies assessing inhibitor development, only one study reported an incidence of a low titre inhibitor, and no patients developed clinically significant inhibitors.

CONCLUSION

rFVIIIFc prophylaxis treatment results in a low ABR across studies in patients with haemophilia A in a European real-world setting, which correlates with findings from clinical trials assessing the efficacy of rFVIIIFc in patients with haemophilia A.

Real-world bleeding outcomes and product utilization in people with severe-type hemophilia A before and after switching to extended half-life rFVIIIFc prophylaxis therapy

BACKGROUND

Recombinant factor VIII-Fc (rFVIIIFc) became available in Taiwan in 2018. Before this date, no people with hemophilia A (PwHA) were enrolled in a clinical trial of rFVIIIFc. We investigated changes in bleeding outcomes and product utilization in PwHA switching from rFVIII to rFVIIIFc.

METHODS

Data were collected for Taiwanese PwHA (severe-type) who switched from rFVIII to rFVIIIFc, including annualized bleeding rate (ABR) and weekly dose consumption 12 months pre-switch and > 6 months post-switch.

RESULTS

The 51 patients were divided into 3 groups according to their pre-switch treatment: on-demand treatment, intermittent periodic prophylaxis, and regular prophylaxis. In every group, the post-switch median ABR was significantly reduced, with no significant differences between groups. Meanwhile, the post-switch median weekly dose of each group was significantly increased. In 32 patients on pre-switch prophylaxis, switching brought a further reduction in median ABR, associated with a significant increase in median weekly dose. No adverse effects or novel inhibitor development were seen.

CONCLUSION

This is the first report from Asia on real-world experience of rFVIIIFc, showing that switching to rFVIIIFc prophylaxis led to further reduction in ABR and increase in weekly dose for all patient groups, even those on pre-switch rFVIII prophylaxis.

Applicability of the European Society of Cardiology Guidelines on the management of acute coronary syndromes to older people with haemophilia A - A modified Delphi consensus by the ADVANCE Working Group

INTRODUCTION

As people with haemophilia (PWH) receive better treatment and live longer they are more likely to encounter cardiovascular disease (CVD) and other comorbidities. ESC guidelines for the acute management of patients presenting with acute coronary syndrome (ACS) are based on the non-haemophilia population.

AIM

To review the guidelines and propose relevant adaptations for PWHA without inhibitors who are treated with prophylaxis and present with ACS.

METHODS

As part of the ADVANCE Group, 20 European haemophilia experts used a modified Delphi approach to develop and gain consensus on proposed adaptations of the ESC guidelines for PWHA without inhibitors.

RESULTS

Of the 32 Class I recommendations across both guidelines, adaptions were considered necessary and proposed for 15. The adaptions highlight the need to provide sufficient FVIII trough levels at the time of antithrombotic treatment in people with haemophilia A (HA) without inhibitors. Patients receiving emicizumab prophylaxis and requiring oral anticoagulation therapy or combined single antiplatelet plus oral anticoagulation therapy will require additional FVIII replacement therapy.

CONCLUSION

In the absence of high-quality clinical evidence, the combined expert opinion used to develop these adaptions to the current ESC guidelines may help to guide clinicians in their treatment decisions when a PWHA presents with ACS.

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.