Three-year outcomes of valoctocogene roxaparvovec gene therapy for hemophilia A

BACKGROUND

Valoctocogene roxaparvovec transfers a human factor VIII (FVIII) coding sequence into hepatocytes of people with severe hemophilia A to provide bleeding protection.

OBJECTIVE

Present 3-year efficacy and safety in the multicenter, open-label, single-arm, phase 3 GENEr8-1 trial.

METHODS

GENEr8-1 enrolled 134 adult males with severe hemophilia A who were receiving FVIII prophylaxis. Efficacy endpoints included annualized bleeding rate (ABR), annualized FVIII utilization (AFU), FVIII activity (chromogenic substrate assay; imputed as 1 IU/dL at baseline and 0 IU/dL after discontinuation), and the Haemophilia-Specific Quality of Life Questionnaire for Adults (Haemo-QOL-A). Safety was assessed by adverse events (AEs).

RESULTS

At week 156, 131/134 participants remained on study; overall, 17/134 resumed prophylaxis. Mean (standard deviation [SD]) treated ABR decreased from 4.8 (6.5) bleeds/year at baseline to 0.8 (SD, 2.3; P <0.0001) bleeds/year during post-prophylaxis (prophylaxis cessation to last follow-up) and 0.97 (SD, 3.48) bleeds/year during year 3. AFU decreased 96.8% from baseline post-prophylaxis and 94.2% during year 3. At week 156, mean and median FVIII activity were 18.4 (SD, 30.8) and 8.3 IU/dL, respectively. FVIII activity decrease was lower between years 2‒3 than 1‒2. At the end of year 3, clinically meaningful improvements in Haemo-QOL-A Total Score were observed (mean change from baseline, 6.6; 95% confidence interval, 4.24‒8.87; P <0.0001). Mild alanine aminotransferase elevations remained the most common AE during year 3 (23.7% of participants). A serious AE of B-cell acute lymphoblastic leukemia was considered unrelated to treatment.

CONCLUSIONS

Hemostatic efficacy was maintained, and safety remained unchanged from previous years.

Benefits and risks of non-factor therapies: Redefining haemophilia treatment goals in the era of new technologies

INTRODUCTION

Over the last decades progress in haemophilia treatment has been remarkable and prophylaxis with clotting factor concentrates in haemophilia A and B has been established as the standard of care in individuals with haemophilia and a severe bleeding phenotype. Besides clotting factor products with prolonged half-life non-factor therapies were developed which enable prophylaxis via subcutaneous administration. Factor VIIIa mimetics like emicizumab facilitate the coagulation pathway and are used in routine clinical practice for indivdiduals with haemophilia A. Rebalancing therapeutic agents like fitusiran, concizumab, marstacimab and serpin PC block the anticoagulant pathway and clinical trials using these products in individuals with haemophilia A and B are ongoing.

AIM AND METHODS

A narrative review to asess the benefits and risks of non-factor therapies taking in to account re-defined haemophilia treatment goals.

RESULTS

Prophylaxis for prevention of bleeds using non-factor products by subcutaneous administration is effective and results in reductions of bleeding episodes in individuals with haemophilia A or B with and without inhibitors. The treatment with emicizumab showed tolerable safety both in clinical trials and long-term real-world observations with few thrombotic events. In some clinical trials with rebalancing therapies (fitusiran and concizumab) thrombotic events occurred. Monitoring of the haemostatic function of novel therapies especially with concomitant haemostatic treatment is not yet established.

CONCLUSION

With the advent of novel therapeutic agents including factor concentrates with ultra-long half-life and improved FVIIIa mimetics aimed at raising the bar of protection into the non-hemophilic range redefinition of haemophilia treatment goals is eagerly needed.

Algorithm for Rapid Exclusion of Clinically Relevant Plasma Levels of Direct Oral Anticoagulants in Patients Using the DOAC Dipstick: An Expert Consensus Paper

BACKGROUND

 With the widespread use of direct oral anticoagulants (DOACs), there is an urgent need for a rapid assay to exclude clinically relevant plasma levels. Accurate and rapid determination of DOAC levels would guide medical decision-making to (1) determine the potential contribution of the DOAC to spontaneous or trauma-induced hemorrhage; (2) identify appropriate candidates for reversal, or (3) optimize the timing of urgent surgery or intervention.

METHODS AND RESULTS

 The DOAC Dipstick test uses a disposable strip to identify factor Xa- or thrombin inhibitors in a urine sample. Based on the results of a systematic literature search followed by an analysis of a simple pooling of five retrieved clinical studies, the test strip has a high sensitivity and an acceptably high negative predictive value when compared with levels measured with liquid chromatography tandem mass spectrometry or calibrated chromogenic assays to reliably exclude plasma DOAC concentrations ≥30 ng/mL.

CONCLUSION

 Based on these data, a simple algorithm is proposed to enhance medical decision-making in acute care indications useful primarily in hospitals not having readily available quantitative tests and 24/7. This algorithm not only determines DOAC exposure but also differentiates between factor Xa and thrombin inhibitors to better guide clinical management.

Measurement of recombinant porcine factor VIII in patients with congenital haemophilia A and inhibitors in the presence of emicizumab

INTRODUCTION

Recombinant porcine factor VIII (rpFVIII) is a treatment option for break-through bleeds in patients with congenital haemophilia A with inhibitors (CHAwI) on emicizumab. However, there are limited data about the measurement of rpFVIII in the presence of emicizumab.

AIM

To analyse whether rpFVIII can be measured with a chromogenic assay with bovine component (bCSA) in plasma from CHAwI on emicizumab treatment.

METHODS

In the first part of the study, FVIII deficient plasma was spiked with rpFVIII, in the second part, commercial plasma from CHAwI was spiked with emicizumab and rpFVIII, and in the third part, plasma from CHAwI on emicizumab treatment was spiked with rpFVIII. FVIII was then measured with bCSA and a chromogenic assay with human component (hCSA). Thrombin generation (TG) and clot-waveform analysis (CWA) were also carried out.

RESULTS

The recovery of rpFVIII measured with bCSA is approximately 80% and is further influenced by the presence of an anti-porcine inhibitor. rpFVIII assessed with hCSA was influenced by emicizumab. CWA and TG showed a weak correlation with baseline emicizumab concentration, but peak thrombin and CWA correlated well with increasing emicizumab concentrations and rpFVIII activities.

CONCLUSION

This study indicates that rpFVIII can be measured in the presence of emicizumab with a bCSA. A calibration curve for the measurement of rpFVIII with bCSA should be established.

[Venous thromboembolism - was is new in the revised AWMF guideline?]

For the diagnosis of a lower-extremity deep vein thrombosis (LEDVT), venous duplex ultrasound is the method of first choice. If a qualified ultrasonography is not timely available, D-dimer testing, and limited ultrasound protocols (point-of-care ultrasound, POCUS) can contribute to therapeutic decision-making when clinical probability is low. A DOAC-based treatment regimen is preferable to a vitamin K antagonist for both acute therapy and secondary prophylaxis of venous thromboembolism (VTE). Treatment with DOACs is unproblematic up to a body weight (BW) of 120 kg or a body mass index (BMI) of 40 kg/m². Weight restrictions are no longer recommended for apixaban and rivaroxaban, but determination of DOAC trough and peak levels is recommended in the extremely obese and patients after bariatric surgery. In cancer-associated VTE, the direct factor Xa inhibitors are a good and safe alternative to low-molecular weight heparins (LMWH) for many patients; the adherence to oral therapy is also higher. Meaningful initial documentation and structured follow-up after LEDVT and pulmonary embolism (PE) are important in order to make an individualized risk-benefit assessment at the end of the therapy phase with regard to continued pharmacological secondary prophylaxis and to reassess patients' symptoms indicating post-thrombotic syndrome (PTS) or chronic thromboembolic pulmonary hypertension (CTEPH).

Indirect treatment comparisons of the gene therapy etranacogene dezaparvovec versus extended half-life factor IX therapies for severe or moderately severe haemophilia B

INTRODUCTION

Etranacogene dezaparvovec gene therapy for haemophilia B demonstrated superior efficacy at 24 months in reducing bleeds versus a ≥6-month lead-in period of prophylaxis with FIX products in the phase 3 trial, HOPE-B. In the absence of head-to-head comparisons of etranacogene dezaparvovec versus FIX products, indirect treatment comparisons (ITC) can be used.

AIM

To compare the efficacy of etranacogene dezaparvovec versus rIX-FP, rFIXFc and N9-GP using ITC, and support HOPE-B results.

METHODS

Data were leveraged from Phase 3 pivotal trials: HOPE-B, PROLONG-9FP, B-LONG and Paradigm 2. Annualised bleeding rates (ABR), spontaneous (AsBR) and joint (AjBR) bleeding rates, percentage of patients with no bleeds, and FIX consumption were assessed using inverse probability of treatment weighting and matching adjusted indirect comparisons.

RESULTS

Etranacogene dezaparvovec demonstrated statistically significantly lower bleeding rates versus all comparators. Rate ratios for ABR, AsBR and AjBR versus rIX-FP were 0.19 (p < .0001), 0.08 (p < .0001) and 0.09 (p < .0001), respectively. Rate ratios for ABR, AsBR and AjBR versus rFIXFc were 0.14 (p < .0001), 0.13 (p = .0083) and 0.15 (p = .0111), respectively. Rate ratios for ABR and AsBR, versus N9-GP were 0.24 (p = .0231) and 0.13 (p = .0071), respectively. Etranacogene dezaparvovec demonstrated significantly higher percentage of patients with no bleeds versus rIX-FP and rFIXFc; odds ratios: 17.60 (p < .0001) and 5.65 (p = .0037), respectively. Etranacogene dezaparvovec resulted in significantly lower FIX consumption than all comparators.

CONCLUSIONS

ITC suggests that etranacogene dezaparvovec offers patients with haemophilia B (≤2% of normal FIX expression) a single dose treatment that can significantly reduce bleeding rates and eliminate routine infusions associated with FIX therapies.

Evaluation of collagen turnover biomarkers as an objective measure for efficacy of treatment with rurioctocog alfa pegol in patients with hemophilia A: a secondary analysis of a randomized controlled trial

BACKGROUND

Patients with hemophilia who have recurrent hemarthroses develop hemophilic arthropathy (HA). Regular prophylaxis with factor (F) VIII (FVIII) can reduce HA, but there is a need for objective outcome measures to evaluate treatment efficacy.

OBJECTIVES

Evaluate and assess collagen turnover biomarkers in patients with hemophilia A to determine the efficacy of rurioctocog alfa pegol treatment and understand their potential as tools for guiding treatment decisions and monitoring outcomes.

METHODS

Joint remodeling was assessed by analyzing serum levels of collagen remodeling products at baseline and months 3, 6, 9, and 12 in a 98 patient subset receiving pharmacokinetics-guided prophylaxis with rurioctocog alfa pegol, targeting FVIII trough levels of 1 to 3 International Units (IU)/dL or 8 to 12 IU/dL (PROPEL study, NCT0285960).

RESULTS

Basement membrane metabolism-related type 4 collagen remodeling products (C4M and PRO-C4) decreased after 3 months at all time points by up to 25% at 1 to 3 IU/dL (P = .049, P < .0001) and 8 to 12 IU/dL FVIII trough levels (P = .0002, P < .0001). Interstitial tissue metabolism-related type 3 (C3M) and 5 (PRO-C5) collagen remodeling products decreased after 3 months, by up to 19% at 1 to 3 IU/dL FVIII trough level (P = .0001, P = .009) and 23% at 8 to 12 IU/dL FVIII trough level (P = .0002, P = .001). An increase of up to 12% was seen for cartilage metabolism-related type 2 collagen product (PRO-C2, not C2M) after 6 months at both trough levels (P = .01, P = .005). When stratified by prior treatment, changes in C3M (P = .03) and C4M (P = .02) levels were observed between trough levels for prior on-demand treatment but not for prophylaxis prior to study entry.

CONCLUSION

Joint improvement measured by collagen remodeling biomarkers specific to the basement membrane, interstitial matrix, and cartilage was seen with pharmacokinetics-guided prophylaxis. These collagen remodeling biomarkers warrant further exploration as biomarkers to guide treatment toward improvement in HA.

Concomitant presentation of thrombotic thrombocytopenic purpura, immune thrombocytopenia, and autoimmune hemolytic anemia in a patient with newly diagnosed systemic lupus erythematosus

Thrombocytopenia is always of concern when encountered in emergency settings. We report a case of a 29-year-old women in whom a unique constellation of hematological disorders occurred. The patient had been diagnosed with idiopathic immune thrombocytopenia (ITP) in 2007, with a history of several thrombocytopenic flares. She now presented with homonymous hemianopia accompanied by thrombocytopenia and microangiopathic hemolytic anemia (MAHA) and was soon after diagnosed with a posterior stroke. Symptoms were more reminiscent of acquired thrombotic thrombocytopenic purpura (aTTP) rather than ITP. Immediate treatment with plasma exchange and caplacizumab curtailed MAHA, and progressive ischemic disease was averted. ADAMTS-13 testing confirmed the diagnosis of immune-mediated aTTP. Repeated testing for ITP, however, also showed IgG-loaded thrombocytes with the former known anti-GPIIb/IIIa specificity. Furthermore, autoimmune hemolytic anemia (AIHA) could be detected by direct antiglobulin test showing IgG and complement loading of the patient's erythrocytes. The autoimmune background of all three entities suggested an underlying systemic disease. Indeed, systemic lupus erythematosus (SLE) serology was strongly positive allowing for the diagnosis of SLE. ITP and AIHA as well as aTTP can be secondary to SLE, but emergence of all three disorders has not been reported at the same time.

Emicizumab for the Treatment of Acquired Hemophilia A: Consensus Recommendations from the GTH-AHA Working Group

BACKGROUND

 Acquired hemophilia A (AHA) is a severe bleeding disorder caused by autoantibodies against coagulation factor VIII (FVIII). Standard treatment consists of bleeding control with bypassing agents and immunosuppressive therapy. Emicizumab is a bispecific antibody that mimics the function of activated FVIII irrespective of the presence of neutralizing antibodies. Recently, the GTH-AHA-EMI study demonstrated that emicizumab prevents bleeds and allows to postpone immunosuppression, which may influence future treatment strategies.

AIM

 To provide clinical practice recommendations on the use of emicizumab in AHA.

METHODS

 A Delphi procedure was conducted among 33 experts from 16 German and Austrian hemophilia care centers. Statements were scored on a scale of 1 to 9, and agreement was defined as a score of ≥7. Consensus was defined as ≥75% agreement among participants, and strong consensus as ≥95% agreement.

RESULTS

 Strong consensus was reached that emicizumab is effective for bleed prophylaxis and should be considered from the time of diagnosis (100% consensus). A fast-loading regimen of 6 mg/kg on day 1 and 3 mg/kg on day 2 should be used if rapid bleeding prophylaxis is required (94%). Maintenance doses of 1.5 mg/kg once weekly should be given (91%). Immunosuppression should be offered to patients on emicizumab if they are eligible based on physical status (97%). Emicizumab should be discontinued when remission of AHA is achieved (97%).

CONCLUSION

 These GTH consensus recommendations provide guidance to physicians on the use of emicizumab in AHA and follow the results of clinical trials that have shown emicizumab is effective in preventing bleeding in AHA.

Health-related quality of life following valoctocogene roxaparvovec gene therapy for severe hemophilia A in the phase 3 trial GENEr8-1

BACKGROUND

Severe hemophilia A (HA) negatively impacts health-related quality of life (HRQOL).

OBJECTIVES

We aimed to analyze HRQOL in adult men with severe HA without inhibitors after valoctocogene roxaparvovec gene transfer in the phase 3 trial GENEr8-1.

METHODS

Participant-reported outcomes were the hemophilia-specific quality of life questionnaire for adults (Haemo-QOL-A), the EQ-5D-5L instrument, the Hemophilia Activities List (HAL), and the Work Productivity and Activity Impairment Questionnaire: Hemophilia Specific (WPAI+CIQ:HS). Participants completed the questionnaires at baseline and through 104 weeks postinfusion with 6 × 1013 vg/kg of valoctocogene roxaparvovec. Scores were analyzed per participant characteristics and outcomes.

RESULTS

For 132 HIV-negative participants, mean change from baseline in Haemo-QOL-A Total Score met the anchor-based clinically important difference (CID: 5.5) by week 12; the mean (SD) increase was 7.0 (12.6) at week 104. At week 104, improvement in Consequences of Bleeding, Treatment Concern, Worry, and Role Functioning domain scores exceeded the CID (6). EQ-5D-5L Utility Index scores improved above the CID at week 52, but not at week 104. EQ-5D-5L visual analog scale and HAL scores increased from baseline to week 104. Participants reported less activity and work impairment at week 104 than baseline. Participants with problem joints had lower mean baseline Haemo-QOL-A Total and domain scores than those without them, but improved over 104 weeks, except for 11 participants with ≥3 problem joints. Participants with 0 bleeds during the baseline prophylaxis period reported Haemo-QOL-A score improvements above the CID, including in the Consequences of Bleeding domain.

CONCLUSION

Valoctocogene roxaparvovec provided clinically meaningful HRQOL improvement for men with severe HA.

Cancer-Associated Venous Thromboembolism-Diagnostic and Therapeutic Considerations: An Update Based on the Revised AWMF S2k Guideline

Patients with cancer are prone to develop venous thromboembolism (VTE) with negative impact on quality of life, morbidity, and mortality. Treatment of established VTE is often complex in patients with cancer. Treatment of cancer-associated VTE (CAT) basically comprises initial and maintenance treatment, for 3 to 6 months, secondary preventions, and treatment in special situations. Therapeutic anticoagulation is the treatment of choice in CAT. In addition to the efficacy and safety of low-molecular-weight heparin (LMWH) that had been recommended for decades, direct oral anti-factor Xa inhibitors, a subgroup of direct oral anticoagulants (DOACs), demonstrated their advantages along with the accompanying concerns in several randomized controlled treatment trials of CAT. The latest guidelines, such as the German AWMF-S2k Guideline "Diagnostics and Therapy of Venous Thrombosis and Pulmonary Embolism," agree with each other on most aspects with respect to the treatment of CAT. Encompassing recent clinical studies, and meta-analyses, as well as the focus on some special management aspects of CAT, the objective of this review is to present a current overview and recommendations for the treatment of CAT.

Accreditation model of European Haemophilia Centres in the era of novel treatments and gene therapy

INTRODUCTION

The international certification of haemophilia centres in Europe is run by the European Association of Haemophilia and Allied Disorders (EAHAD) and European Haemophilia Consortium (EHC) since 2013. The centres are designated as European Haemophilia Comprehensive Care Centres (EHCCC) or European Haemophilia Treatment Centres (EHTC), based on the specific requirements which evaluate centres' ability to provide care for patients with haemophilia and allied disorders.

AIM

To establish the new protocol for accreditation of European Haemophilia Centres.

METHODS

EAHAD, in collaboration with EHC, established Accreditation Working Group with the aim to define necessary measures to safeguard quality and improvement of bleeding disorders care throughout Europe and to build a novel model for accreditation of European Haemophilia Centres.

RESULTS

The European guidelines for certification of haemophilia centres have been updated to guidelines for the accreditation and include all the requirements regarding facilities, laboratory and personnel needed for optimal management of novel treatment options, including the introduction of the hub-and-spoke model for delivery of gene therapy. A pilot project for the accreditation of haemophilia centres including on-site audit has been designed.

CONCLUSION

Implementation of the novel accreditation protocol of the haemophilia treatment and haemophilia gene therapy centres has been made to further improve the quality of care for patients with haemophilia and other inherited bleeding disorders.

Emicizumab prophylaxis in patients with acquired haemophilia A (GTH-AHA-EMI): an open-label, single-arm, multicentre, phase 2 study

BACKGROUND

Acquired haemophilia A is caused by neutralising autoantibodies against coagulation factor VIII, leading to severe bleeding. Standard treatment involves immunosuppressive therapy, which is associated with adverse events and mortality in the frail population of patients with acquired haemophilia A. This study investigated whether emicizumab, a factor VIIIa mimetic antibody, protects patients with acquired haemophilia A from bleeding and allows deferral of immunosuppression during the first 12 weeks after diagnosis.

METHODS

We report final results of an open-label, single-arm, phase 2 clinical trial. Adult patients with acquired haemophilia A from 16 haemophilia treatment centres in Germany and Austria were eligible if they had not previously received immunosuppression. Patients received emicizumab subcutaneously (6 and 3 mg/kg on days 1 and 2, 1·5 mg/kg weekly until week 12), but no immunosuppression. Follow-up was until week 24. The primary endpoint was the number of clinically relevant bleeds per patient-week until week 12. Emicizumab was considered effective if the mean bleeding rate was significantly below 0·15 bleeds per patient-week, the rate observed in a previous study of patients with acquired haemophilia A treated with bypassing agents and immunosuppression but no emicizumab. The study is registered with clinicaltrials.gov, NCT04188639 and is complete.

FINDINGS

Of 49 patients screened from March 25, 2021, to June 10, 2022, 47 were enrolled (23 women, 24 men). Median age was 76 years (IQR 66-80), 46 (98%) of 47 patients were White, median factor VIII activity was 1·4 IU/dL (0·3-5·6), and median inhibitor concentration was 11·4 Bethesda units per mL (3·9-42·7). Mean breakthrough bleeding rate was 0·04 bleeds per patient-week (upper 97·5% CI 0·06). 33 (70%) of 47 patients had no bleeding events, seven patients (15%) had one bleed, six patients (13%) had two bleeds, and one patient (2%) had three bleeds. Adverse events of grade 3 or worse included COVID-19 (n=2), acute kidney injury (n=2), and stroke (n=1). Four of 47 patients died, including two deaths related to bleeding, one from COVID-19, and one from cardiac arrest (none were judged as related to emicizumab).

INTERPRETATION

This study suggests that emicizumab prophylaxis prevents bleeding in patients with acquired haemophilia A and that immunosuppressive therapy can be deferred while patients are receiving this treatment. The low number of thromboembolic events, severe infections, and fatalities observed in this study are promising.

FUNDING

This study was supported by funding from Hoffman-La Roche.

Efficacy of rFIXFc versus N9-GP Prophylaxis in Patients with Hemophilia B: Matching-Adjusted Indirect Comparison of B-LONG and PARADIGM 2 Trials

Purpose

For patients with hemophilia B, extended half-life factor IX (FIX) products are available for prophylaxis and for treating bleeds. Different methods are used to extend the half-lives of recombinant FIX Fc fusion protein (rFIXFc) and nonacog beta pegol (N9-GP). This affects their biodistribution and plasma FIX levels, although differences do not always correlate with clinical outcomes. A matching-adjusted indirect comparison (MAIC) of prophylaxis with rFIXFc and N9-GP was performed, based on licensed dosing in the European Union.

Patients and Methods

Combined rFIXFc data from the weekly and individualized interval prophylaxis arms of the B-LONG clinical trial, and N9-GP data from the 40 IU/kg once-weekly prophylaxis arm of PARADIGM 2 were used in a MAIC. Individual patient data for rFIXFc (n=87) were matched to aggregated data for N9-GP (n=29). Estimated annualized bleeding rates (ABRs) for rFIXFc were recalculated using a Poisson regression model with adjustment for over-dispersion, and compared with ABRs reported for N9-GP, using incidence rate ratios (IRRs) with 95% confidence interval (CI).

Results

There was no evidence of significant differences in estimated ABRs between prophylaxis with rFIXFc and N9-GP. Analysis of pooled rFIXFc weekly and interval-adjusted dosing compared with N9-GP 40 IU/kg once weekly produced estimated ABRs of 2.59 versus 2.51 (IRR 1.03; 95% CI 0.56-1.89), as well as 1.34 versus 1.22 (IRR 1.10; 95% CI 0.42-2.91) and 1.13 versus 1.29 (IRR 0.88; 95% CI 0.47-1.63) for overall, spontaneous, and traumatic bleeding events, respectively.

Conclusion

The study did not reveal any significant differences in the efficacy of rFIXFc and N9-GP prophylaxis. Given differences in trough levels (rFIXFc dosing was targeted to achieve a trough 1-3 IU/dL above baseline versus a reported estimated N9-GP mean trough of 27.3 IU/dL), interpreting plasma FIX levels as potential surrogate efficacy markers requires consideration of compound-specific pharmacokinetic profiles.

Targeting an elevated FVIII level using personalized rurioctocog alfa pegol prophylaxis in specific patient populations with hemophilia A: post hoc subanalysis of the randomized, phase 3 PROPEL study

Background

The phase 3, prospective PROPEL study demonstrated that pharmacokinetic (PK)-guided prophylaxis targeting elevated factor VIII (FVIII) troughs in patients with hemophilia A resulted in lower annualized bleeding rates (ABRs) and a higher proportion of patients experiencing zero bleeds in the second 6 months of treatment when targeting a FVIII trough of 8-12% versus 1-3%.

Objective

To investigate the benefit of PK-guided prophylaxis with rurioctocog alfa pegol targeting two FVIII trough levels in specific patient subgroups in a post hoc analysis using data from PROPEL.

Design

This is a post hoc analysis of data from the PROPEL study. The design and primary outcomes of the prospective, randomized PROPEL study (NCT02585960) have been reported previously.

Methods

This post hoc analysis reports data stratified by FVIII half-life (t1/2), hemophilic arthropathy status, number of target joints at screening, previous treatment regimen, and ABR range in the 12 months before study entry.

Results

Targeting an elevated FVIII trough of 8-12% was associated with higher average FVIII levels over time, regardless of FVIII t1/2 at baseline. The decrease in total ABR between the 8-12% and 1-3% arms was greatest in patients with a FVIII t1/2 of 6 to <12 h (0.7 versus 3.5); a higher number of target joints, that is, at least four target joints, at baseline (0.2 versus 1.6); the presence of arthropathy (0.1 versus 1.7); and those previously treated on-demand (0.3 versus 1.8).

Conclusion

These results support the feasibility of targeting elevated FVIII levels using personalized rurioctocog alfa pegol prophylaxis. These benefits may be especially important in patients with a short FVIII t1/2 and those receiving standard prophylaxis with frequent breakthrough bleeds, arthropathy, and target joints.

Registration

ClinicalTrials.gov Identifier: NCT02585960; https://clinicaltrials.gov/ct2/show/NCT02585960.

Matching-adjusted indirect comparison of bleeding outcomes in severe haemophilia A: Comparing valoctocogene roxaparvovec gene therapy, emicizumab prophylaxis, and FVIII replacement prophylaxis

INTRODUCTION

Head-to-head evaluation of valoctocogene roxaparvovec, the first gene therapy approved for haemophilia A, with emicizumab is not available. Therefore, phase 3 trial data were indirectly compared.

AIM

To compare bleeding rates in trials evaluating 6 × 10¹³  vg/kg valoctocogene roxaparvovec (GENEr8-1; NCT03370913), 1.5 mg/kg emicizumab dosed every week (HAVEN 3; NCT02847637), and FVIII prophylaxis (270-902) in participants with severe haemophilia A (FVIII ≤1 IU/dL).

METHODS

Valoctocogene roxaparvovec versus emicizumab and FVIII prophylaxis as used in 270-902 versus emicizumab cross-trial comparisons were performed using matching-adjusted indirect comparison (MAIC). Individual participant data from GENEr8-1 and 270-902 were weighted to equalise aggregate participant baseline characteristics from HAVEN 3. After MAIC weighting, annualised bleeding rates (ABR) and proportions of participants without bleeds were compared for treated bleeds, all bleeds, treated joint bleeds, and treated spontaneous bleeds.

RESULTS

After MAIC weighting, ABR for all bleeds was statistically significantly lower with valoctocogene roxaparvovec than emicizumab (rate ratio [95% CI], .55 [.33-.93]). Additionally, significantly higher proportions of participants had no treated joint bleeds (odds ratio [95% CI], 2.75 [1.20-6.31]) and no treated bleeds (3.25 [1.53-6.90]) with valoctocogene roxaparvovec versus emicizumab. When compared with the mainly standard half-life FVIII prophylaxis regimens in 270-902, mean ABRs (except for all bleeds) were significantly lower, and significantly higher proportions reported 0 bleeds for all outcomes with emicizumab.

CONCLUSION

Valoctocogene roxaparvovec provided generally lower bleeding rates and higher probability of no bleeds, including treated joint bleeds, than emicizumab. Emicizumab was more effective than FVIII prophylaxis regimens used in 270-902.

Antithrombotic Treatment in Patients With Hemophilia: an EHA-ISTH-EAHAD-ESO Clinical Practice Guidance

Cardiovascular disease is an emerging medical issue in patients with hemophilia (PWH) and its prevalence is increasing up to 15% in PWH in the United States. Atrial fibrillation, acute and chronic coronary syndromes, venous thromboembolism, and cerebral thrombosis are frequent thrombotic or prothrombotic situations, which require a careful approach to fine-tune the delicate balance between thrombosis and hemostasis in PWH when using both procoagulant and anticoagulant treatments. Generally, PWH could be considered as being naturally anticoagulated when clotting factors are <20 IU/dL, but specific recommendations in patients with very low levels according to the different clinical situations are lacking and mainly based on the anecdotal series. For PWH with baseline clotting factor levels >20 IU/dL in need for any form of antithrombotic therapy, usually treatment without additional clotting factor prophylaxis could be used, but careful monitoring for bleeding is recommended. For antiplatelet treatment, this threshold could be lower with single-antiplatelet agent, but again factor level should be at least 20 IU/dL for dual antiplatelet treatment. In this complex growing scenario, the European Hematology Association in collaboration with the International Society on Thrombosis and Haemostasis, the European Association for Hemophilia and Allied Disorders, the European Stroke Organization, and a representative of the European Society of Cardiology Working Group on Thrombosis has produced this current guidance document to provide clinical practice recommendations for health care providers who care for PWH.

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.

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.

Synovitis and joint health in patients with haemophilia: Statements from a European e-Delphi consensus study

INTRODUCTION

Synovitis, a common feature in haemophilia, is triggered by the presence of blood in joints, and represents the first step towards the development of chronic arthropathy. Synovitis may be detected early by means of ultrasound or magnetic resonance imaging scan; clinical joint scores are less sensitive in this setting. Regular long-term prophylaxis with clotting factor concentrates, as primary prophylaxis and tailored to individual needs, has high efficacy in preventing synovitis. In general, higher factor levels lower bleeding risk, but no direct correlation between factor levels and synovitis incidence has been demonstrated.

AIM

This study aimed to develop an expert consensus relating to the definition, pathophysiology, diagnosis, prevention, follow-up and treatment of synovitis, recognising its relevance for joint health and taking into account existing knowledge gaps.

METHODS

A Delphi consensus study was designed and performed. An expert group prepared 22 statements based on existing literature; a wider expert panel subsequently voted on these.

RESULTS

Retention of panellists was high. Four statements required amending and consensus on all statements was achieved after three rounds of voting.

CONCLUSION

This e-Delphi consensus study addressed the importance of synovitis in joint health of people with haemophilia and highlighted knowledge gaps in this field. Studies on the natural course of synovitis are lacking and the biological mechanisms underlying this process are not yet fully elucidated. While basic and clinical research proceeds in this field, expert consensus can help guide clinicians in their routine clinical practice, and Delphi methodology is often used to produce best-practice guidelines.

Fitusiran prophylaxis in people with severe haemophilia A or haemophilia B without inhibitors (ATLAS-A/B): a multicentre, open-label, randomised, phase 3 trial

BACKGROUND

Fitusiran, a subcutaneous investigational siRNA therapeutic, targets antithrombin with the goal of rebalancing haemostasis in people with haemophilia A or haemophilia B, regardless of inhibitor status. We aimed to evaluate the efficacy and safety of fitusiran prophylaxis in people with severe haemophilia without inhibitors.

METHODS

This multicentre, open-label, randomised phase 3 study was conducted at 45 sites in 17 countries. Male participants aged at least 12 years with severe haemophilia A or B without inhibitors, who had previously been treated on-demand with clotting factor concentrates, were randomly assigned in a 2:1 ratio to receive 80 mg subcutaneous fitusiran prophylaxis once per month or to continue on-demand clotting factor concentrates for a total of 9 months. Randomisation was stratified by the number of bleeding events in the 6 months before screening (≤10 bleeds and >10 bleeds) and by haemophilia type (haemophilia A or B). The primary endpoint was annualised bleeding rate, analysed in the intention-to-treat analysis set. Safety and tolerability were assessed in the safety analysis set. This trial is registered with ClinicalTrials.gov, NCT03417245, and is complete.

FINDINGS

Between March 1, 2018, and July 14, 2021, 177 male participants were screened for eligibility and 120 were randomly assigned to receive fitusiran prophylaxis (n=80) or on-demand clotting factor concentrates (n=40). Median follow-up was 7·8 months (IQR 7·8-7·8) in the fitusiran group and 7·8 months (7·8-7·8) in the on-demand clotting factor concentrates group. The median annualised bleeding rate was 0·0 (0·0-3·4) in the fitusiran group and 21·8 (8·4-41·0) in the on-demand clotting factor concentrates group. The estimated mean annualised bleeding rate was significantly lower in the fitusiran prophylaxis group (3·1 [95% CI 2·3-4·3]) than in the on-demand clotting factor concentrates group (31·0 [21·1-45·5]; rate ratio 0·101 [95% CI 0·064-0·159]; p<0·0001). In the fitusiran group, 40 (51%) of 79 treated participants had no treated bleeds compared with two (5%) of 40 participants in the on-demand clotting factor concentrates group. Increased alanine aminotransferase concentration (18 [23%] of 79 participants in the safety analysis set) was the most common treatment-emergent adverse event in the fitusiran group and hypertension (four (10%) of 40 participants) was the most common in the on-demand clotting factor concentrates group. Treatment-emergent serious adverse events were reported in five (6%) participants in the fitusiran group (cholelithiasis [n=2, 3%], cholecystitis [n=1, 1%], lower respiratory tract infection [n=1, 1%], and asthma [n=1, 1%]) and five (13%) participants in the on-demand clotting factor concentrates group (gastroenteritis, pneumonia, suicidal ideation, diplopia, osteoarthritis, epidural haemorrhage, humerus fracture, subdural haemorrhage, and tibia fracture [all n=1, 3%]). No treatment-related thrombosis or deaths were reported.

INTERPRETATION

In participants with haemophilia A or B without inhibitors, fitusiran prophylaxis resulted in significant reductions in annualised bleeding rate compared with on-demand clotting factor concentrates and no bleeding events in approximately half of participants. Fitusiran prophylaxis shows haemostatic efficacy in both haemophilia A and haemophilia B, and therefore has the potential to be transformative in the management of all people with haemophilia.

FUNDING

Sanofi.

Gene Therapy with Etranacogene Dezaparvovec for Hemophilia B

BACKGROUND

Moderate-to-severe hemophilia B is treated with lifelong, continuous coagulation factor IX replacement to prevent bleeding. Gene therapy for hemophilia B aims to establish sustained factor IX activity, thereby protecting against bleeding without burdensome factor IX replacement.

METHODS

In this open-label, phase 3 study, after a lead-in period (≥6 months) of factor IX prophylaxis, we administered one infusion of adeno-associated virus 5 (AAV5) vector expressing the Padua factor IX variant (etranacogene dezaparvovec; 2×10¹³ genome copies per kilogram of body weight) to 54 men with hemophilia B (factor IX activity ≤2% of the normal value) regardless of preexisting AAV5 neutralizing antibodies. The primary end point was the annualized bleeding rate, evaluated in a noninferiority analysis comparing the rate during months 7 through 18 after etranacogene dezaparvovec treatment with the rate during the lead-in period. Noninferiority of etranacogene dezaparvovec was defined as an upper limit of the two-sided 95% Wald confidence interval of the annualized bleeding rate ratio that was less than the noninferiority margin of 1.8. Superiority, additional efficacy measures, and safety were also assessed.

RESULTS

The annualized bleeding rate decreased from 4.19 (95% confidence interval [CI], 3.22 to 5.45) during the lead-in period to 1.51 (95% CI, 0.81 to 2.82) during months 7 through 18 after treatment, for a rate ratio of 0.36 (95% Wald CI, 0.20 to 0.64; P<0.001), demonstrating noninferiority and superiority of etranacogene dezaparvovec as compared with factor IX prophylaxis. Factor IX activity had increased from baseline by a least-squares mean of 36.2 percentage points (95% CI, 31.4 to 41.0) at 6 months and 34.3 percentage points (95% CI, 29.5 to 39.1) at 18 months after treatment, and usage of factor IX concentrate decreased by a mean of 248,825 IU per year per participant in the post-treatment period (P<0.001 for all three comparisons). Benefits and safety were observed in participants with predose AAV5 neutralizing antibody titers of less than 700. No treatment-related serious adverse events occurred.

CONCLUSIONS

Etranacogene dezaparvovec gene therapy was superior to prophylactic factor IX with respect to the annualized bleeding rate, and it had a favorable safety profile. (Funded by uniQure and CSL Behring; HOPE-B ClinicalTrials.gov number, NCT03569891.).

Clinical experience of switching patients with severe hemophilia to rVIII-SingleChain or rIX-FP

OBJECTIVE

Prophylaxis treatment is the current standard of care for patients with severe hemophilia. Factor concentrates with improved pharmacokinetics have offered more options for individualizing treatment. The treatment focus may be on increased protection, aiming for higher trough factor levels or longer dosing intervals to reduce the burden of hemophilia. Both aspects can have long-term effects on joint health. Products, such as rVIII‑SingleChain and rIX-FP have been developed to reduce the treatment burden for patients with hemophilia and optimize prophylactic efficacy. The objective of this report is to provide a summary of the clinical experience of different Hemophilia Treatment Centers in managing the switch to rVIII-SingleChain or rIX-FP in patients with hemophilia.

METHODS

This report summarizes a selection of patient cases presented at the 3rd Alliance for Coagulation Academy Meeting in October 2020. The cases from the participating centers provide examples of the clinical experience in managing patients' switch to rVIII-SingleChain and rIX‑FP, including which types of patients are suitable for switching, and practical steps in managing a switch.

RESULTS

It is important to take into consideration the physical and social fulfillment of the patient when deciding to switch to rVIII-SingleChain or rIX-FP. The physician plays an important role in the motivation of patients as they understand not only the patient's needs but the potential benefits of the new treatment.

CONCLUSION

The selected patient cases reported here demonstrate that patients may wish to switch factor products for a variety of reasons; therefore, it is critical to understand why patients switch and what they expect from switching.

Efanesoctocog Alfa Prophylaxis for Patients with Severe Hemophilia A

BACKGROUND

Efanesoctocog alfa provides high sustained factor VIII activity by overcoming the von Willebrand factor-imposed half-life ceiling. The efficacy, safety, and pharmacokinetics of efanesoctocog alfa for prophylaxis and treatment of bleeding episodes in previously treated patients with severe hemophilia A are unclear.

METHODS

We conducted a phase 3 study involving patients 12 years of age or older with severe hemophilia A. In group A, patients received once-weekly prophylaxis with efanesoctocog alfa (50 IU per kilogram of body weight) for 52 weeks. In group B, patients received on-demand treatment with efanesoctocog alfa for 26 weeks, followed by once-weekly prophylaxis with efanesoctocog alfa for 26 weeks. The primary end point was the mean annualized bleeding rate in group A; the key secondary end point was an intrapatient comparison of the annualized bleeding rate during prophylaxis in group A with the rate during prestudy factor VIII prophylaxis. Additional end points included treatment of bleeding episodes, safety, pharmacokinetics, and changes in physical health, pain, and joint health.

RESULTS

In group A (133 patients), the median annualized bleeding rate was 0 (interquartile range, 0 to 1.04), and the estimated mean annualized bleeding rate was 0.71 (95% confidence interval [CI], 0.52 to 0.97). The mean annualized bleeding rate decreased from 2.96 (95% CI, 2.00 to 4.37) to 0.69 (95% CI, 0.43 to 1.11), a finding that showed superiority over prestudy factor VIII prophylaxis (P<0.001). A total of 26 patients were enrolled in group B. In the overall population, nearly all bleeding episodes (97%) resolved with one injection of efanesoctocog alfa. Weekly prophylaxis with efanesoctocog alfa provided mean factor VIII activity of more than 40 IU per deciliter for the majority of the week and of 15 IU per deciliter at day 7. Prophylaxis with efanesoctocog alfa for 52 weeks (group A) improved physical health (P<0.001), pain intensity (P = 0.03), and joint health (P = 0.01). In the overall study population, efanesoctocog alfa had an acceptable side-effect profile, and the development of inhibitors to factor VIII was not detected.

CONCLUSIONS

In patients with severe hemophilia A, once-weekly efanesoctocog alfa provided superior bleeding prevention to prestudy prophylaxis, normal to near-normal factor VIII activity, and improvements in physical health, pain, and joint health. (Funded by Sanofi and Sobi; XTEND-1 ClinicalTrials.gov number, NCT04161495.).

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.

Efficacy and safety of damoctocog alfa pegol prophylaxis in patients ⩾40 years with severe haemophilia A and comorbidities: post hoc analysis from the PROTECT VIII study

Background

Advances in treatment have enabled patients with haemophilia A to live longer and therefore may be subjected to comorbidities associated with ageing, in addition to disease-associated morbidities. There have been few reports to date on efficacy and safety of treatment specifically in patients with severe haemophilia A and comorbidities.

Objective

To explore the efficacy and safety of damoctocog alfa pegol prophylaxis in patients with severe haemophilia A aged ⩾40 years with comorbidities of interest.

Design

A post hoc analysis of data from the phase 2/3 PROTECT VIII study and its extension.

Methods

Bleeding and safety outcomes were analysed in a subgroup of patients aged ⩾40 years with ⩾1 comorbidity receiving damoctocog alfa pegol (BAY 94-9027; Jivi^®) prophylaxis.

Results

Thirty-four patients with severe haemophilia A were included in this analysis, with a mean age of 49.4 years at time of enrolment. The most prevalent comorbidities were hepatitis C (n = 33; chronic, n = 23), hepatitis B (n = 8) and hypertension (n = 11). Four patients had human immunodeficiency virus. All received damoctocog alfa pegol prophylaxis for the entire study [median (range) time in study = 3.9 (1.0-6.9) years]. During the main study and extension, median total annualised bleeding rates (ABRs) (Q1; Q3) were 2.1 (0.0; 5.8) and 2.2 (0.6; 6.0), respectively; median joint ABRs were 1.9 (0.0; 4.4) and 1.6 (0.0; 4.0), respectively. Mean adherence with prophylaxis schedule was greater than 95% throughout the study. No deaths or thrombotic events were reported.

Conclusion

Efficacy, safety and adherence of damoctocog alfa pegol were confirmed in patients aged ⩾40 years with haemophilia A and one or more comorbidities, with data for up to 7 years supporting its use as a long-term treatment option in this group.

Plain language summary

Advances in treatment mean that people with haemophilia A are now living longer and, as a result, may have additional medical conditions that occur with ageing. We aimed to investigate the efficacy and safety of the long-acting replacement factor VIII damoctocog alfa pegol in people with severe haemophilia A who had additional medical conditions. To do this, we investigated the recorded information about patients aged 40 years of age or older who had been treated with damoctocog alfa pegol in a previously completed clinical trial. We found that the treatment was well-tolerated; no deaths or thrombotic events (undesirable clotting events) were reported. Treatment was efficacious in reducing bleeding in this group of patients. The findings support the use of damoctocog alfa pegol as a long-term treatment for older patients with haemophilia A and coexisting conditions.

Gene Therapy for Hemophilia-Opportunities and Risks

BACKGROUND

AAV (adeno-associated virus)-based gene therapy is a new treatment for hemophilia and has recently received approval for the treatment of severe hemophilia A. It does not suffer from the limitations of the current standard treatment (regular prophylactic intravenous injections of the missing clotting factor; subcutaneous injection of a bispecific antibody in hemophilia A) and can, it is hoped, raise the concentration of the missing clotting factor over the long term. AAV-based gene therapy can only be performed once, however, because of the generation of antibodies to AAV.

METHODS

This review is based on publications retrieved by a selective search in the MEDLINE/PubMed database employing the relevant key words, supplemented by expert opinions and the recommendations of the relevant medical societies.

RESULTS

Data from non-randomized phase 1 to phase 3 trials reveal an adequate expression of factors VIII and IX in patients with mostly severe hemophilia A or B. Even though they were no longer receiving prophylactic treatment, most patients experienced a considerable reduction, by 53% to 96%, in the number of bleedings compared to previous therapy. Persistently elevated factor levels have been described for up to six years in hemophilia A and up to eight years in hemophilia B. The most common side effect of gene therapy is an inflammatory response with elevated alanine aminotransferase levels (17% to 89%, depending on the study), which may be associated with a reduced clotting factor level and requires treatment with transient immunosuppression.

CONCLUSION

Gene therapy for hemophilia holds out the prospect of freedom from hemorrhage without the need for regular treatment with drugs. The various steps that need to be carried out in gene therapy should be coordinated in a graded and partly overlapping integrated care model (a so-called hub-and-spoke model). Electronic platforms should be used for data acquisition and transmission.

Gene therapy of Hemophilia: Recommendations from the German, Austrian, and Swiss Society for Thrombosis and Haemostasis Research (GTH)

Gene therapy has recently become a realistic treatment perspective for patients with hemophilia. Reviewing the literature and our personal experience from clinical trials, we discuss key aspects of hemophilia A and B gene therapy with vectors derived from adeno-associated virus, including predictable results, risks, adverse events, and patient-reported outcomes. Patient selection, informed consent, administration, and monitoring of gene therapy as well as data collection are explained. We also discuss the need for interdisciplinary cooperation with hepatology and other specialties. We emphasize structural and organizational requirements for treatment centers according to the hub-and-spoke model and recommend the use of electronic diaries to ensure safe and timely collection and exchange of data. Electronic diaries will play a key role as a primary source of data for pharmacovigilance, postmarketing clinical studies, national and international registries, as well as health technology and benefit assessment. Reimbursement aspects and the future of gene therapy in adolescents and children are also considered. In a rapidly evolving scientific environment, these recommendations aim to support treatment providers and payers to prepare for the implementation of gene therapy following marketing authorization.

Safety and efficacy of long‐term emicizumab prophylaxis in hemophilia A with factor VIII inhibitors: A phase 3b, multicenter, single‐arm study ( STASEY )

Background

The bispecific monoclonal antibody emicizumab bridges activated factor IX and factor X, mimicking the cofactor function of activated factor VIII (FVIII), restoring hemostasis.

Objectives

The Phase 3b STASEY study was designed to assess the safety of emicizumab prophylaxis in people with hemophilia A (HA) with FVIII inhibitors.

Methods

People with HA received 3 mg/kg emicizumab once weekly (QW) for 4 weeks followed by 1.5 mg/kg QW for 2 years. The primary objective was the safety of emicizumab prophylaxis, including incidence and severity of adverse events (AEs) and AEs of special interest (thrombotic events [TEs] and thrombotic microangiopathies). Secondary objectives included efficacy (annualized bleed rates [ABRs]).

Results

Overall, 195 participants were enrolled; 193 received emicizumab. The median (range) duration of exposure was 103.1 (1.1-108.3) weeks. Seven (3.6%) participants discontinued emicizumab. The most common AEs were arthralgia (n = 33, 17.1%) and nasopharyngitis (n = 30, 15.5%). The most common treatment-related AE was injection-site reaction (n = 19, 9.8%). Two fatalities were reported (polytrauma with fatal head injuries and abdominal compartment syndrome); both were deemed unrelated to emicizumab by study investigators. Two TEs occurred (myocardial infarction and localized clot following tooth extraction), also deemed unrelated to emicizumab. The negative binomial regression model-based ABR (95% confidence interval) for treated bleeds was 0.5 (0.27-0.89). Overall, 161 participants (82.6%) had zero treated bleeds.

Conclusions

The safety profile of emicizumab prophylaxis was confirmed in a large population of people with HA with FVIII inhibitors and no new safety signals occurred. The majority of participants had zero treated bleeds.

Turoctocog alfa pegol (N8‐GP) in severe hemophilia A: Long‐term safety and efficacy in previously treated patients of all ages in the pathfinder8 study

Background

N8‐GP (turoctocog alfa pegol; Esperoct) is a glycoPEGylated human recombinant factor VIII (FVIII).

Objectives

Pathfinder8 (NCT01480180) was a phase 3, multinational, open‐label, nonrandomized trial to investigate the long‐term safety and efficacy of N8‐GP in people of all ages with severe hemophilia A previously treated with N8‐GP.

Patients/Method

Patients were recruited from the completed phase 3 pathfinder2 and pathfinder5 trials to receive intravenous N8‐GP prophylaxis for up to 104 weeks, administered every 7 days, twice weekly, or three times weekly. Primary and secondary end points were the number of adverse events (AEs) reported and efficacy of treatment, respectively.

Results

Overall, 160 patients were exposed to N8‐GP for a mean of 179 exposure days and 681 calendar days (≈1.9 years) per patient. In total, 119 patients experienced 510 AEs, corresponding to a rate of 1.71 AEs per patient‐year of exposure; 97.5% of AEs were mild or moderate in severity, and no AEs led to withdrawal. No patients developed FVIII inhibitors during the trial. The Poisson estimate of mean annualized bleeding rate for all bleeds (excluding surgery) and across all regimens was 1.10 (median, 0.00), and for spontaneous bleeds was 0.61 (median, 0.00). Most (55.6%) patients experienced no bleeds that required FVIII treatment (excluding perioperative bleeds). The estimated hemostatic success rate for the treatment of 322 bleeding episodes (excluding surgery) was 95.8%, including missing values as failure.

Conclusions

Long‐term prophylactic use of N8‐GP appeared safe and efficacious across all age groups in people with severe hemophilia A previously treated with N8‐GP.

Electronic diaries in the management of haemophilia gene therapy: Perspective of an expert group from the German, Austrian and Swiss Society on Thrombosis and Haemostasis (GTH)

INTRODUCTION

Gene therapy (GT) is becoming a realistic treatment option for patients with haemophilia. Outside clinical trials, the complexity and potential complications of GT will pose unprecedented challenges to haemophilia care centres.

AIM

To explore the potential use of electronic tools to improve the delivery of GT under real-world conditions.

METHODS

Considering the hub-and-spoke model, the GTH working group on GT considered the entire patient pathway and reached consensus on requirements for an integrative software tool to secure documenting and sharing information between treaters, pharmacies and patients.

RESULTS

Six steps of the gene therapy process were identified, each requiring completion of the previous step as a prerequisite for entry. The responsibilities of GT dosing and follow-up treatment centres, read/write access rules, and the minimum data set were outlined. Data contributed by patients through mobile devices was also considered.

CONCLUSION

Important information needs to be shared between patients and treatment centres in a real-world GT hub-and-spoke model. Collecting and sharing this information in well-organised electronic applications will not only improve patient care but also enable national and international data collection in clinical registries.

Global seroprevalence of pre-existing immunity against AAV5 and other AAV serotypes in people with hemophilia A

Adeno-associated virus (AAV)-mediated gene therapy may provide durable protection from bleeding events and reduce treatment burden for people with hemophilia A (HA). However, pre-existing immunity against AAV may limit transduction efficiency and hence treatment success. Global data on the prevalence of AAV serotypes are limited. In this global, prospective, noninterventional study, we determined the prevalence of pre-existing immunity against AAV2, AAV5, AAV6, AAV8, and AAVrh10 among people ≥12 years of age with HA and residual FVIII levels ≤2 IU/dL. Antibodies against each serotype were detected using validated, electrochemiluminescent-based enzyme-linked immunosorbent assays. To evaluate changes in antibody titers over time, 20% of participants were retested at 3 and 6 months. In total, 546 participants with HA were enrolled at 19 sites in 9 countries. Mean (standard deviation) age at enrollment was 36.0 (14.87) years, including 12.5% younger than 18 years, and 20.0% 50 years of age and older. On day 1, global seroprevalence was 58.5% for AAV2, 34.8% for AAV5, 48.7% for AAV6, 45.6% for AAV8, and 46.0% for AAVrh10. Considerable geographic variability was observed in the prevalence of pre-existing antibodies against each serotype, but AAV5 consistently had the lowest seroprevalence across the countries studied. AAV5 seropositivity rates were 51.8% in South Africa (n = 56), 46.2% in Russia (n = 91), 40% in Italy (n = 20), 37.2% in France (n = 86), 26.8% in the United States (n = 71), 26.9% in Brazil (n = 26), 28.1% in Germany (n = 89), 29.8% in Japan (n = 84), and 5.9% in the United Kingdom (n = 17). For all serotypes, seropositivity tended to increase with age. Serostatus and antibody titer were generally stable over the 6-month sampling period. As clinical trials of AAV-mediated gene therapies progress, data on the natural prevalence of antibodies against various AAV serotypes may become increasingly important.

Anticoagulation Practice in Patients with Cancer-Associated Thrombosis: Insights from GeCAT, a German Prospective Registry Study

INTRODUCTION

Cancer-associated venous thrombosis (CAT) is a common and serious complication of active malignancies, increasing in frequency during systemic treatment and radiotherapy. Due to a high risk of recurrence and bleeding, the administration of anticoagulants for initial treatment and secondary prevention of CAT is challenging. We conducted a prospective registry study of patients with acute CAT to evaluate the way treatment is given to these patients in routine practice.

METHODS

From May 2015 to May 2017, all consecutive patients with acute venous thromboembolism (VTE) admitted to specialty or emergency departments of the participating hospitals in Berlin, Germany, were entered in the registry. Patients with cancer underwent extensive baseline evaluation including the type and location of thrombosis and use of anticoagulant therapy. Follow-up assessments were made at discharge and by telephone interviews at 3 and 6 months.

RESULTS

A total of 382 patients with acute CAT were enrolled in the study, representing 24.5% of all patients with thrombosis. 70.4% of CAT patients had deep vein thromboses (DVT), 48.2% had pulmonary embolism (PE), and 18.6% had concurrent PE and DVT. A significant proportion of VTE (27%) were asymptomatic and were diagnosed only incidentally. At baseline, 97.9% of the patients received anticoagulant therapy, predominantly with low-molecular-weight heparin (LMWH) (n=334, 87.4%). Direct oral anticoagulants (DOACs) were given to 5.8% of patients, and vitamin K antagonists (VKAs) were rarely used (<2% of patients). Changes in the prescription of antithrombotic agents were seen at discharge from hospital and during follow-up. Overall, the use of LMWH declined during follow-up, while the proportion of patients treated with DOACs increased to 32.4% at 6 months. At baseline, the most frequently used LMWH were enoxaparin and nadroparin, but many patients were switched to once daily tinzaparin prior to discharge. Initially and after discharge the majority of patients were treated by oncologists. Overall, 263 (68.8%) and 222 (58,1%) patients were still alive and could be contacted at 3 and 6 months of follow-up, respectively. Of these, 84.0% and 71.6% were still on anticoagulant therapy (58.6% and 36.5% on LMWH).

CONCLUSION

In accordance with the guidelines, the majority of CAT patients received anticoagulation therapy for the recommended minimum duration of 3-6 months. LMWH remained the preferred option throughout the study, demonstrating good patient adherence. In deviation from guideline recommendations and available study results during the study period, more than a quarter of CAT patients were treated with DOACs. Only recently, DOACs have been established as another option for anticoagulation in CAT patients.

Immune tolerance induction in the era of emicizumab - still the first choice for patients with haemophilia A and inhibitors?

INTRODUCTION

The development of inhibitory antibodies is a severe complication of clotting factor replacement therapy in patients with severe haemophilia A (HA). Current World Federation of Hemophilia (WFH) guidelines for haemophilia care indicate that eradication of inhibitors is best achieved through immune tolerance induction (ITI) therapy.

AIM

The European Collaborative Haemophilia Network conducted a survey to determine whether ITI is still used in the routine management of patients with HA, and whether the availability of emicizumab prophylaxis has influenced treatment decisions.

METHODS

The survey was conducted in late 2020/early 2021 in 18 centres representing 17 countries in the Europe/Middle East region treating a total of 4955 patients, and included sections specific to patient and centre demographics, treatment protocols (both ITI and prophylactic), inhibitor development and initiation of ITI, treatment success, and the incidence of adverse events.

RESULTS

While our results indicate that ITI can still be considered a mainstay of treatment for patients with HA with inhibitors, less than daily dosing of ITI in combination with emicizumab prophylaxis is becoming commonplace across the spectrum of disease severity, with initiation being guided by bleeding patterns. The most frequently cited reasons for not initiating emicizumab prophylaxis were availability or reimbursement issues.

CONCLUSION

ITI remains a mainstay for haemophilia treatment of patients with HA with inhibitors, but emicizumab has become a preferred first-line approach to protect against bleeds and represents an alternative to burdensome ITI in certain patient groups.

Indirect Treatment Comparison of Damoctocog Alfa Pegol versus Turoctocog Alfa Pegol as Prophylactic Treatment in Patients with Hemophilia A

Purpose

To assess the efficacy and FVIII consumption of BAY 94-9027 versus N8-GP in prophylaxis in adolescent and adult patients with severe hemophilia A (HA).

Patients and Methods

A systematic literature review was conducted to identify studies on the efficacy of BAY-94-9027 and N8-GP for prophylaxis in patients with HA aged ≥12 years without a history of inhibitors. Eight studies met systematic literature review inclusion criteria, but only data from PROTECT VIII on BAY 94-9027 and PATHFINDER 2 on N8-GP could be used for an indirect comparison. Matching-adjusted indirect comparison (MAIC) and simulated treatment comparison were performed.

Results

No significant differences (unadjusted and adjusted) were observed in the mean annualized bleeding rate (ABR) for any bleed and proportion of patients with zero bleeds when comparing BAY 94-9027 to N8-GP. The adjusted treatment difference [incidence rate ratio (IRR)] in terms of ABR was 1.11 (95% CI, 0.85–1.44). The odds ratio (OR) of any bleed, measuring the relative effect of BAY 94-9027 versus N8-GP on the proportion of patients with zero bleeds, was 1.03 (95% CI, 0.60–1.77). FVIII consumption was significantly lower in BAY 94-9027 [mean adjusted difference=−1292.57 IU/kg/year (95% CI, ‒2152.44 to ‒432.70)]; a 26.7% reduction in consumption of BAY-94-9027. The results of the sensitivity analyses were similar to the main analysis for mean ABRs, percentages of patients with zero bleeds, and significant reduction in rFVIII consumption. For patients on BAY 94-9027 every-5-days and every-7-days, no differences versus every-4-days N8-GP were observed for the mean ABR for any bleed [IRR=0.90 (95% CI, 0.68‒1.20)] and proportion of patients with zero bleeds [OR=1.06 (95% CI, 0.56‒2.02)].

Conclusion

BAY 94-9027 prophylaxis demonstrated 26.7% lower annual consumption when compared to N8-GP with similar efficacy in terms of ABR and percentage of patients with zero bleeds.

Delivery of AAV-based gene therapy through haemophilia centres-A need for re-evaluation of infrastructure and comprehensive care: A Joint publication of EAHAD and EHC

INTRODUCTION

Adeno-associated virus (AAV)-based gene therapy for haemophilia presents a challenge to the existing structure of haemophilia centres and requires a rethink of current collaboration and information exchange with the aim of ensuring a system that is fit-for-purpose for advanced therapies to maximise benefits and minimise risks. In Europe, a certification process based on the number of patients and facilities is offered to the haemophilia centres by European Haemophilia Network (EUHANET).

AIM AND METHODS

This joint European Association for Haemophilia and Allied Disorders (EAHAD) and European Haemophilia Consortium (EHC) publication describes criteria for centres participating in gene therapy care that require a reassessment of the infrastructure of comprehensive care and provides an outlook on how these criteria can be implemented in the future work of haemophilia centres.

RESULTS

The core definition of a haemophilia treatment centre remains, but additional roles could be implemented. A modifiable 'hub-and-spoke' model addresses all aspects associated with gene therapy, including preparation and administration of the gene therapy product, determination of coagulation and immunological parameters, joint score and function, and liver health. This will also include the strategy on how to follow-up patients for a long-term safety and efficacy surveillance.

CONCLUSION

We propose a modifiable, networked 'hub and spoke' model with a long term safety and efficacy surveillance system. This approach will be progressively developed with the goal of making haemophilia centres better qualified to deliver gene therapy and to make gene therapy accessible to all persons with haemophilia, irrespective of their country or centre of origin.

New Inhibitors in the Ageing Population: A Retrospective, Observational, Cohort Study of New Inhibitors in Older People with Hemophilia

INTRODUCTION

 A second peak of inhibitors has been reported in patients with severe hemophilia A (HA) aged >50 years in the United Kingdom. The reason for this suggested breakdown of tolerance in the aging population is unclear, as is the potential impact of regular exposure to the deficient factor by prophylaxis at higher age. No data on hemophilia B (HB) have ever been reported.

AIM

 The ADVANCE Working Group investigated the incidence of late-onset inhibitors and the use of prophylaxis in patients with HA and HB aged ≥40 years.

METHODS

 A retrospective, observational, cohort, survey-based study of all patients aged ≥40 years with HA or HB treated at an ADVANCE hemophilia treatment center.

RESULTS

 Information on 3,095 people aged ≥40 years with HA or HB was collected. Of the 2,562 patients with severe HA, the majority (73% across all age groups) received prophylaxis. In patients with severe HA, the inhibitor incidence per 1,000 treatment years was 2.37 (age 40-49), 1.25 (age 50-59), and 1.45 (age 60 + ). Overall, the inhibitor incidence was greatest in those with moderate HA (5.77 [age 40-49], 6.59 [age 50-59], and 4.69 [age 60 + ]) and the majority of inhibitor cases were preceded by a potential immune system challenge. No inhibitors in patients with HB were reported.

CONCLUSION

 Our data do not identify a second peak of inhibitor development in older patients with hemophilia. Prophylaxis may be beneficial in older patients with severe, and possibly moderate HA, to retain a tolerant state at a higher age.

Efficacy of rFIXFc versus rIX-FP for the Treatment of Patients with Hemophilia B: Matching-Adjusted Indirect Comparison of B-LONG and PROLONG-9FP Trials

Purpose

In patients with hemophilia B, treatment with extended half-life (EHL) recombinant factor IX allows for longer dosing intervals while providing equal or superior bleeding protection compared with standard half-life products. This enables flexible, individualized treatment schedules, which reduce the burden of prophylaxis and improve patient outcomes. This analysis compared the efficacy of recombinant factor IX Fc fusion protein (rFIXFc) and recombinant factor IX albumin fusion protein (rIX-FP), two EHL therapies approved for prophylaxis and treatment of bleeding in hemophilia B.

Patients and Methods

Matching-adjusted indirect treatment comparison (MAIC) was used to adjust the between-treatment differences in baseline characteristics. Individual patient data for rFIXFc (B-LONG) were matched to aggregated data for rIX-FP (PROLONG-9FP) followed by statistical comparison for estimated annualized bleeding rate (ABR) using a Poisson regression model with adjustment for over dispersion. Data were analyzed according to treatment regimen prior to study entry: prior prophylaxis (rFIXFc, n=48; rIX-FP, n=40) or prior episodic treatment (n=43 and n=19, respectively). Relative treatment effects are presented as incidence rate ratios (IRR) with 95% confidence intervals (CI).

Results

After adjustment for baseline characteristics, estimated ABR observed for rFIXFc and rIX-FP was not significantly different in patients on prior prophylaxis (1.87 versus 1.58; IRR 1.18, 95% CI 0.67–2.10) or prior episodic (2.25 versus 2.22; IRR 1.01 95% CI 0.40–2.57) regimens.

Conclusion

This MAIC analysis shows that the estimated ABR for rFIXFc-treated patients from B-LONG was similar to that of rIX-FP-treated patients from PROLONG-9FP and, therefore, indicates that the two EHL therapies provide similar efficacy when used as prophylaxis for patients with hemophilia B. Trough levels differ between the two products (1–3% [targeted] versus 20% [observed], respectively), suggesting that trough level is not a surrogate indicator when ABR is used as a criterion for clinical efficacy when comparing these FIX products in hemophilia B.

Factor VIII activity and bleeding risk during prophylaxis for severe hemophilia A: a population pharmacokinetic model

During factor VIII prophylaxis for severe hemophilia A, bleeding risk increases with time when factor VIII activity is below 1%. However, maintaining trough activity above 1% does not protect all patients from bleeding. The relationship between factor VIII activity during prophylaxis and bleeding risk has not been thoroughly studied. We investigated factor VIII activity and annualized bleeding rate for spontaneous bleeds during prophylaxis. A population pharmacokinetic model derived from three clinical trials was combined with dosing data and information on bleeding from patients’ diaries. Each patient’s time on prophylaxis was divided into five categories of predicted activity (0-1%, >1-5%, >5-15%, >15-50%, and >50%). Exposure time, mean factor VIII activity, and number of bleeds (from the patients’ diaries) were calculated for each activity category, and annualized bleeding rates estimated using negative binomial regression and a parametric model. Relationships between these bleeding rates and factor VIII activity were evaluated by trial phase (pivotal vs. extension) and age (adults/adolescents [≥12 years] vs. children [0-<12 years]). In total (n=187 patients; 815 patient-years’ exposure), factor VIII activity was predicted to be >1% for 85.64% of the time. The annualized bleeding rate decreased as factor VIII activity increased in each trial phase and age group. However, for a given activity level, bleeding rate differed substantially by trial phase and age. This suggests that bleeding risk can change over time and is influenced by factors independent of factor VIII pharmacokinetics and trough levels. When making decisions regarding target trough levels and the prophylactic regimen, the patients’ age, joint disease activity, and other bleeding risk determinants should be taken into consideration. Clinical trial registration numbers: NCT00840086; NCT01138501; NCT00984126

Consensus Recommendations for Intramuscular COVID-19 Vaccination in Patients with Hemophilia

BACKGROUND

 Currently available coronavirus disease 2019 (COVID-19) vaccines are approved for intramuscular injection and efficacy may not be ensured when given subcutaneously. For years, subcutaneous vaccination was recommended in patients with hemophilia to avoid intramuscular bleeds. Therefore, recommendations for the application of COVID-19 vaccines are needed.

METHODS

 The Delphi methodology was used to develop consensus recommendations. An initial list of recommendations was prepared by a steering committee and evaluated by 39 hemophilia experts. Consensus was defined as ≥75% agreement and strong consensus as ≥95% agreement, and agreement as a score ≥7 on a scale of 1 to 9. After four rounds, a final list of statements was compiled.

RECOMMENDATIONS

 Consensus was achieved that COVID-19 vaccines licensed only for intramuscular injection should be administered intramuscularly in hemophilia patients. Prophylactic factor replacement, given on the day of vaccination with a maximum interval between prophylaxis and vaccination of 24 hours (factor VIII and conventional factor IX concentrates) or 48 hours (half-life extended factor IX), should be provided in patients with moderate or severe hemophilia. Strong consensus was achieved that patients with mild hemophilia and residual factor activity greater than 10% with mild bleeding phenotype or patients on emicizumab usually do not need factor replacement before vaccination. Swelling, erythema, and hyperthermia after vaccination are not always signs of bleeding but should prompt consultation of a hemophilia care center. In case of injection-site hematoma, patients should receive replacement therapy until symptoms disappear.

CONCLUSIONS

 Consensus was achieved on recommendations for intramuscular COVID-19 vaccination after replacement therapy for hemophilia patients depending on disease severity.

Diagnosis and Management of Vaccine-Related Thrombosis following AstraZeneca COVID-19 Vaccination: Guidance Statement from the GTH

The COVID-19 pandemic is an ongoing global healthcare crisis. Based on reports of atypically located thromboses following vaccination with the AstraZeneca COVID-19 vaccine, the Society of Thrombosis and Haemostasis Research (GTH) has issued guidance statements on the recognition, diagnosis, and treatment of this rare complication. It shares pathophysiological features with heparin-induced thrombocytopenia (HIT) and is referred to as vaccine-induced prothrombotic immune thrombocytopenia (VIPIT).