Optimal treatment strategies for hemophilia: achievements and limitations of current prophylactic regimens

Treatment of Bleeding Episodes With Efanesoctocog Alfa in Previously Treated Patients With Severe Hemophilia A in the Phase 3 XTEND-1 Study

Despite therapeutic advances, people with hemophilia experience bleeds. These may be life-threatening, result in permanent joint damage, chronic pain, difficulties with mobility/daily activities, and impact quality of life. In the XTEND-1 study (NCT04161495), once-weekly efanesoctocog alfa (50 IU/kg) prophylaxis provided highly effective bleed prevention and high-sustained factor levels for most of the week and was well-tolerated. We report post hoc analysis of bleeding episodes and their treatment in previously treated patients (≥ 12 years old). Participants received 50 IU/kg efanesoctocog alfa either as once-weekly prophylaxis (Arm A) or on-demand followed by once-weekly prophylaxis (Arm B) in XTEND-1. Endpoints included treatment of bleeding episodes and response to treatment. During XTEND-1, 422 bleeding episodes were reported among 159 participants; 362 were treated. Most treated bleeding episodes (74%; n = 268) occurred during the Arm B on-demand period, of which 197 (74%) were spontaneous. Seventy-five participants had no bleeding episodes in Arm A; all in Arm B had ≥ 1 bleeding episode while on-demand. Most participants (n = 107, 81%) had zero treated spontaneous bleeding episodes and rates of treated bleeding episodes in Arm A (prophylaxis) were low (median [interquartile range] overall ABR: 0.00 [0.00-1.04]). A single injection was sufficient to resolve 97% (350/362) of treated bleeding episodes, no bleeding episodes required > 3 injections, and responses to 95% of evaluable injections were rated excellent/good. Median total dose was 50.9 IU/kg per bleeding episode. Results of this analysis further demonstrated that once-weekly efanesoctocog alfa provides highly effective bleed protection and treatment of bleeding episodes in participants with severe hemophilia A. Trial Registration: NCT04161495.

The proportion of young male hemophilia patients who underwent ultrasound examinations: an observational study using a nationwide claims database

BACKGROUND

Advances in hemophilia treatment have reduced bleeding episodes in patients with hemophilia (PWH) and improved their musculoskeletal prognosis; however, complete prevention of musculoskeletal disorders has not been achieved. Recently, the usefulness of ultrasound (US) examinations in the musculoskeletal assessment of PWH has been reported, but the actual use of US has been suggested to be limited. The aim of this study was to clarify the extent to which US is being performed on young male PWH at medical institutions in Japan.

METHODS

This was an observational study using the National Database of Health Insurance Claims and Specific Health Checkups of Japan. We identified almost all male PWH aged under 30 years who were prescribed hemostatic agents between 2015 and 2021 in Japan. For each year, we calculated the proportion of PWH who underwent US and, as a sensitivity analysis, the proportion of PWH who underwent US examinations for musculoskeletal disease. The Cochran‒Armitage trend test was used to examine changes in the number of PWH who underwent US examinations over the observation period. The Lorenz curves and Gini coefficients were calculated from the proportion of US examinations performed at each medical institution annually.

RESULTS

A total of 2137-2483 male PWH younger than 30 years were identified annually. The annual proportion of PWH who underwent US ranged from 6.1 to 12.9%. By age group, the annual proportions of US were 6.7-14.4%, 8.1-16.6%, and 2.0-8.7% for 0-9, 10-19, and 20-29 years, respectively. The annual proportions of musculoskeletal US were 2.9-7.7%. The proportion of PWH who underwent US increased significantly over the seven-year period; however, it varied by medical institution (Gini coefficients 0.85-0.92).

CONCLUSIONS

The use of US for young PWH is becoming more widespread in Japan. However, US is performed at different rates among medical institutions.

Impact of Systematic Joint Examination (Ultrasound, Functional and Physical) on Treatment Management Decisions in Patients With Haemophilia A in France: Final Data From the Prospective, Observational A-MOVE Study

BACKGROUND

Haemophilia management aims to prevent bleeding and preserve joint function. Changes in patients' joint health may influence physicians' decisions to adjust treatment. The Haemophilia Joint Health Score (HJHS) and Haemophilia Early Arthropathy Detection with Ultrasound (HEAD-US) score assess joint health but are not routinely used.

AIM

To evaluate whether systematic joint examination with HJHS and/or HEAD-US had an impact on treatment management decisions in France, using final data from the A-MOVE study.

METHODS

A-MOVE (NCT04133883) was a 12-month prospective, multicentre study, which enrolled persons with haemophilia A (all severities, aged 6-40 years) treated prophylactically or on demand with standard/extended half-life FVIII replacement. At baseline, 6 and 12 months, HJHS/HEAD-US and changes in patients' management were assessed.

RESULTS

Eighty-six patients from 20 sites were included in the final analysis; 68 had HJHS/HEAD-US assessments at 12 months. Over 12 months, 24.4% (n = 21/86) of patients experienced an impact on their haemophilia management due to HJHS/HEAD-US scores; these decisions were impacted by HJHS in about half of the patients (52.4%, n = 11/21) and HEAD-US in almost all patients (95.2%, n = 20/21). Both assessments contributed to a change in management decisions in about half of the patients (47.6%, n = 10/21). Twenty-nine patients (33.7%) had haemophilia management decisions impacted by factors other than HJHS/HEAD-US, including physical examination findings (n = 9) and the occurrence of bleeding episodes (n = 8).

CONCLUSIONS

Final data from the A-MOVE study show that systematic joint assessments, through functional/physical examination (HJHS) and ultrasound (HEAD-US), may impact treatment management decisions in persons with haemophilia A.

Superior Prophylactic Effectiveness of a Recombinant FVIIIFc Over Standard Half-Life FVIII in Hemophilia A: A-SURE Study

OBJECTIVES

The 24-month, prospective, non-interventional, European multicenter A-SURE study evaluated the real-world effectiveness of prophylaxis using an extended half-life recombinant factor VIII (FVIII) Fc fusion protein, efmoroctocog alfa (hereinafter rFVIIIFc), compared with prophylaxis using standard half-life (SHL) FVIII products in patients with hemophilia A.

METHODS

Primary endpoints were annualized bleeding rate (ABR), annualized injection frequency, and annualized factor consumption. A comparative study design unique for an observational hemophilia study was implemented to reduce potential confounding in effectiveness estimates, wherein each patient prescribed rFVIIIFc was matched with one receiving SHL FVIII. Propensity scores were used for adjustment in statistical analyses.

RESULTS

Outcomes for all primary endpoints were significantly better in the rFVIIIFc group (n = 184) compared with the SHL FVIII group (n = 170): mean ABR 1.5 versus 2.3 (difference of -0.8; p = 0.0147); mean annualized injection frequency 114.4 versus 169.2 (difference of -54.8; p < 0.0001); and mean annualized factor consumption 243 024.2 versus 288 718.6 International Units (difference of 45 694.5; p = 0.0003). rFVIIIFc was well tolerated, with no inhibitor development.

CONCLUSIONS

rFVIIIFc has superior prophylactic effectiveness versus SHL FVIII, providing higher bleed protection with fewer injections and lower factor consumption.

Intensive FVIII replacement in hemophilia patients with hypertrophic synovium: a randomized study

BACKGROUND

Hypertrophic synovium (HS) is a marker of disease activity in persons with hemophilia (PwH). Although some recommendations suggest intensifying prophylaxis in PwH with HS, no validated schedules are available.

OBJECTIVES

We explored the efficacy of intensive factor VIII (FVIII) replacement treatment in PwH with HS.

METHODS

In a randomized, open-label study, PwH with HS were randomized to receive pharmacokinetics-driven prophylaxis targeting a FVIII trough level of 8% to 12% (intensive treatment arm [ITA]) or 3% to 5% (standard treatment arm [STA]). The primary outcome was HS reduction/resolution in the 2 treatment arms.

RESULTS

A total of 39 PwH were randomized to ITA and 36 to STA. During the study, we found a lower annual bleeding rate and a higher rate of annual bleeding rate zero in the ITA than in the STA. HS reduction/resolution was reported in 35.9% of cases in the ITA and 8.4% in the STA. In detail, in the ITA ,10.3% achieved HS reduction and 25.6% complete HS resolution, as compared to 5.6% and 2.8% in the STA. Cox regression showed that ITA was associated with HS reduction/resolution (hazard ratio: 4.75; 95% CI: 1.36-16.57; P = .014) and HS complete resolution (hazard ratio: 10.79; 95% CI: 1.38-84.45; P = .023). The analysis of the 127 joints with HS (54 elbows, 41 knees, and 32 ankles) consistently confirmed similar results.

CONCLUSION

In this randomized study, we found a ∼5-fold higher rate of HS reduction/resolution and a ∼10-fold higher rate of HS resolution in the ITA than in the STA.

The Evolution of Hemophilia Pharmacological Treatments and Therapeutic Targets at the Turn of the Third Millennium

Historically, the aim of treatment for hemophilia, the congenital X-linked hemorrhagic disorder due to deficiencies of coagulation Factor (F) VIII (hemophilia A) or FIX (hemophilia B), has been the replacement through factor concentrates, whose regular administration (i.e., prophylaxis) has been shown to be highly effective in preventing bleeding complications and it is currently considered the gold standard of hemophilia treatment. However, continuous technological progress (i.e., plasma-derived factor concentrates, recombinant standard and extended half-life [EHL] products) has allowed clinicians operating at hemophilia treatment centers to individualize the management of persons with hemophilia, improving outcomes, adherence to therapy, and their quality of life. The achievement of normal hemostasis, the final goal that now seems possible with new-generation EHL products, non-replacement and gene therapies, will translate into normalization of life for persons with hemophilia, also addressing health equity (i.e., rendering them indistinguishable from their healthy peers). The evolution of hemophilia treatment and, in parallel, of therapeutic targets in the management of hemophilia patients over the last decades will be critically discussed in this narrative review.

Joint health status in people with moderate hemophilia A: a cross-sectional multicenter study

Background

The prevalence of arthropathy in people with moderate hemophilia A (mHA) is highly variable. People with mHA are often undertreated, and this may lead to joint damage and worsen their quality of life.

Objectives

The aim of the present study was to evaluate joint status in mHA by means of point-of-care ultrasound (PoCUS) and clinical examination.

Methods

Consecutive people with mHA receiving on-demand replacement treatment underwent a clinical examination of joint status according to the Hemophilia Joint Health Score (HJHS) protocol. On the same day, all patients underwent a PoCUS assessment according to the Hemophilia Early Detection by UltraSound (HEAD-US) protocol.

Results

A total of 51 subjects were included. The median HJHS score was 2.0 (IQR, 0-3.0). A 0 to 1 HJHS score was found in 23 people with mHA (45.1%), between 2 and 3 in 17 (33.3%) and >3 in 11 (21.6%). The median HEAD-US score was 2.0 (IQR, 1-7), and a statistically significant correlation between HJHS and HEAD-US was found (rho = 0.732; P < .001). Osteochondral damage was found in 21.6% of patients, and hypertrophic synovium (HS) was found in 29.4%. Among those reporting a 0 to 1 HJHS score, 13.0% showed HS. Analysis at the joint level showed that the most commonly affected joint was the ankle, both for osteochondral damage and the presence of HS.

Conclusion

Our study suggests that the prevalence of arthropathy changes in people with mHA receiving on-demand treatment is not negligible and that PoCUS is able to detect osteochondral damage as well as HS in this clinical setting. A more extensive screening of the joint status could be useful to tailor treatment and improve outcomes in mHA.

Factor Replacement Treatment for Hemophilia A: Achievements and Perspectives

The mainstay of treatment for persons with hemophilia A (PwHA) with severe bleeding phenotype is prophylaxis. The pharmacokinetic (PK) profile of native factor VIII (FVIII) imposes the need for rather frequent intravenous injections to ensure effective prophylaxis, but this represents a relevant treatment burden and is associated with suboptimal adherence to treatment. In this light, the advent of extended half-life (EHL) FVIII molecules has improved prophylaxis feasibility and outcomes by favoring treatment individualization and tailoring protection according to specific clinical and nonclinical needs. Different technologies have been used to enhance FVIII PK properties including Fc-fusion and conjugation with polyethylene glycol. Data from clinical development programs for such molecules, together with growing real-world experience, have shown numerous benefits related to the use of EHL FVIII in PwHA. Recently a new class of ultra-long-acting EHL FVIII has been developed to further improve protection against bleeding episodes and achieve the ambitious goal of providing PwHA with hemostatic protection in the nonhemophilia range over longer time periods, hence ensuring very low bleeding rates and improving joint health and quality of life. In this review, the achievements and perspectives of replacement therapies for PwHA are summarized and discussed.

Examining downstream effects of concizumab in hemophilia A with a mathematical modeling approach

BACKGROUND

Tissue factor (TF) pathway inhibitor (TFPI) is an anticoagulant protein that inhibits factor (F)Xa, the TF-FVIIa-FXa complex, and early forms of the prothrombinase complex. Concizumab is a monoclonal antibody that blocks FXa inhibition by TFPI and reduces bleeding in hemophilia.

OBJECTIVES

To examine how concizumab impacts various reactions of TFPI to restore thrombin generation in hemophilia A using mathematical models.

METHODS

A compartment model was used to estimate plasma concentrations of free concizumab and its complexes with TFPIα and TFPIβ. Concizumab was integrated into a flow-mediated mathematical model of coagulation, and a small injury was simulated under hemophilia A conditions. Simulations were then analyzed to determine how concizumab's blockade of TFPI anticoagulant activities, specifically the inhibition of FXa in plasma and on platelets, inhibition of TF:FVIIa at the subendothelium, and prior sequestration of plasma TFPIα to the endothelium via TFPIβ, altered thrombin generation.

RESULTS

Concizumab improved simulated thrombin generation in hemophilia A by simultaneously altering all 3 mechanisms of the TFPI anticoagulant blockade examined. Concizumab sequestered ∼75% of plasma TFPIα through the formation of ternary TFPIα-concizumab-TFPIβ-complexes. For all TF levels, reducing the TFPIα plasma concentration had the largest impact on the lag time, followed by blocking TFPIα inhibition of TF:FVIIa:FXa and subsequently by blocking TFPIα inhibition of FXa in plasma and on the platelet surface.

CONCLUSION

The effectiveness of concizumab is mediated through the blockade of TFPI anticoagulant activities in plasma and on multiple physiological surfaces. An important and previously unrecognized function of concizumab was the sequestration of plasma TFPIα to the endothelium.

Moderate haemophilia A: Recommendations from a Spanish panel of experts

INTRODUCTION

Diagnosing moderate haemophilia A (MHA) solely based on deficient FVIII protein levels limits its optimal management and delays the initiation of prophylaxis. Updating protocols and incorporating new variables into its diagnosis could prevent underestimating disease severity, avoiding early arthropathies and impairing patients' quality of life.

AIM

To propose recommendations to improve the comprehensive management of people with MHA.

METHODS

Recommendations from a Spanish panel of eight experts from public comprehensive care centres (CCCs) for people with haemophilia and over 140 people with MHA in follow-up. In a previous analysis, the panel identified the unmet needs of people with MHA and the necessity to develop new specific recommendations for their management.

RESULTS

The panel proposed recommendations in four areas: diagnosis, treatment, follow-up and referrals. They detailed the necessary steps and procedures for the diagnosis, adding other variables to the FVIII levels like bleeding phenotype, genetic profile and joint status to specify the severity and risk classification of people with MHA. Experts proposed an algorithm with unique independent criteria to facilitate the decision to initiate prophylaxis, where the recommended FVIII levels and variables coexist for treatment decision-making. Follow-up proposals addressed periodicity, recommended tests and required visits to CCCs. For referrals, experts proposed criteria and situations considered urgent for a transfer to a CCC for haemophilia patients.

CONCLUSION

The proposals agreed upon by this expert panel can contribute to update and optimize the management of people with MHA, delaying joint deterioration, pain and disabilities, and improving their quality of life.

Contemporary approaches to treat people with hemophilia: what's new and what's not?

The care of people with hemophilia with access to treatment has evolved over the past 70 years, with an average life expectancy like unaffected peers. For people with hemophilia living in low- and middle-income countries, the same is not true because of the lack of access to diagnosis and treatment. It is imperative to close gaps in care that exist throughout the world. Here, we provide a narrative review of hemophilia and the treatments available to people with hemophilia A and B with the goal of achieving a hemophilia-free state. We aim to provide information on what is new and what gaps remain that preclude equitable outcomes for everyone with hemophilia. Information on the current state of hemophilia care and outcomes, the products available for the treatment of people with hemophilia, comprehensive interdisciplinary care of people with hemophilia, and the remaining gaps in care for people with hemophilia were assembled by the authors using relevant literature. Research must focus on preventing all bleeding, and new approaches to detect joint bleeding are needed. Training on and implementation of comprehensive interdisciplinary care is needed to elevate the standards of care in low- and middle-income countries. The development and introduction of improved factor replacement and nonfactor products, such as second-generation bispecific monoclonal antibodies and targeted inhibitors of the anticoagulant mechanisms along with genetic therapies, have the possibility of normalizing hemostasis and achieving health equity for people with hemophilia. Improved outcomes and, ultimately, health equity, can only be realized if diagnosis, education, and care are accessible to everyone living with hemophilia worldwide.

Pain-Related Quality of Life Outcomes in People With Haemophilia A Receiving Emicizumab: A Post Hoc Analysis of the HAVEN 1, 3 and 4 and STASEY Studies

INTRODUCTION

People with haemophilia A (PwHA) experience acute and chronic pain associated with reduced quality of life (QoL).

AIMS

This post hoc analysis of pooled data from the HAVEN 1 (NCT02622321), 3 (NCT02847637), 4 (NCT03020160) and STASEY (NCT0319179) studies assessed the impact of emicizumab prophylaxis on pain-related QoL in PwHA.

METHODS

PwHA received emicizumab during the four studies. In this analysis, pain was assessed using patient-reported responses to pain-specific questions from the Haem-A-QoL/Haemo-QoL-SF and the pain/discomfort dimension of the EQ-5D-5L. Responses were recorded at baseline and at regular intervals for up to 78 weeks following treatment initiation. Additional analyses evaluated the population with target joints at baseline, and the overall population stratified by age, factor (F)VIII inhibitor status and prior treatment.

RESULTS

At the data cut-off, 504 PwHA had been treated across the four studies; 464 and 470 completed the Haem-A-QoL/Haemo-QoL-SF and the EQ-5D-5L, respectively. Improvements in pain-related QoL were observed by Week 13 of emicizumab prophylaxis and maintained through Week 78. In the overall population, responses of 'never/rarely' for 'my swellings hurt' and 'pain in joints' increased from 37.0% and 30.0% at baseline to 84.0% and 61.0% by Week 13, suggesting reductions in acute and chronic pain, respectively. Similar improvements were seen in the target joint population, and across all strata. Greater improvements were observed in younger versus older PwHA.

CONCLUSION

Pain-related QoL improved with emicizumab prophylaxis regardless of target joints, age, FVIII inhibitor status or prior treatment. Haemophilia-specific assessments are needed to accurately capture and characterize pain in PwHA.

The Health-Related Quality of Life scores and joint health in children and young adults with hemophilia

BACKGROUND

Patients with hemophilia should be evaluated for joint health and overall health in their visits. The aims of this study were to evaluate joint health and health-related quality of life (HRQoL) in patients with mild, moderate, and severe hemophilia; determine which patient groups to focus on and whether there are any neglected patient groups.

METHODS

This was a single-center, cross-sectional study. Patients were evaluated by ultrasonography (Hemophilia Early Arthropathy Detection with Ultrasound [HEAD-US]), physical examination (Hemophilia Joint Health Score version 2.1 [HJHS-2.1]), and HRQoL scales (EQ-5D/EQ-VAS and Haemo-QoL).

RESULTS

Thirty-nine patients with regular follow-up were evaluated for a total of 234 joints. When hemophilia severity was compared with the HEAD-US and HJHS-2.1, a significant difference was found between severe and non-severe hemophilia. On the other hand, when patients' total HEAD-US scores were compared with total HJHS-2.1 scores, no statistically significant correlations were found; only a statistically significant but negligible correlation was detected when HEAD-US and HJHS-2.1 scores were examined at joint level. No significant difference was found when mild, moderate or severe hemophilia were compared with the HRQoL scores. Also, HEAD-US scores and HRQoL scores were not correlated, showing that the HRQoL score did not change whether the patient has arthropathy or not.

CONCLUSION

Despite recent advances in treatment options for hemophilia, arthropathy in patients with severe hemophilia remains challenging. For the follow-up of pediatric hemophilia, the HEAD-US and HJHS should be used together because their correlation was weak. Although patients with severe hemophilia are at higher risk in terms of arthropathy, patients with mild/moderate hemophilia should not be ignored because their HRQoL is not different from that of severe hemophilia.

Advances in biopharmaceutical products for hemophilia

Hemophilia is caused by the deficiency of clotting factors due to a single genetic abnormality. Replacement therapies have evolved from plasma-derived to recombinant coagulation factor concentrates but continue to have certain limitations. Monoclonal antibodies are clinical prophylactic treatment options unaffected by inhibitors and have better compliance than coagulation factor concentrates for patients with hemophilia. Gene therapy is a breakthrough in hemophilia treatment, as it drives the hepatic expression of factor VIII or factor IX and requires only a single administration to enable long-term replacement treatment in adult patients. Furthermore, biopharmaceutical products that target new pathways unaffected by inhibitors, including tissue factor pathway inhibitors, activated protein C, and antithrombin, as well as pharmaceutical technology advances to reduce dosing frequency, have demonstrated promising clinical results. This review provides a comprehensive overview of these biopharmaceutical products and explores the future of hemophilia treatment.

Initial investigation into patellofemoral morphology in hemophilic arthritis patients

Background

Hemophilic arthritis (HA) is associated with significant changes in the morphology of mature knee joints due to abnormal growth plate development. Previous studies have established marked distinctions between the femur and tibia of subjects with Haemophilia and those with osteoarthritis (OA). This study explored the morphological characteristics of the patella and patellofemoral joint in subjects with Haemophilia. These findings can inform the design of knee joint prostheses tailored to this condition, improve the precision of total knee replacement surgery, and reduce postoperative knee pain and patellar dislocation.

Methods

Before surgery, we conducted preoperative measurements of patellar length, patellar diagonal length, patellar ligament length, patellar width, patellar thickness, the INSALL index, the lateral patellofemoral angle, the trochlear groove angle,the patellar lateral displacement rate, and the patellofemoral index using lateral and axial x-ray images in 40 subjects with Haemophilia, 40 OA patients, and 40 normal individuals.

Results

Significant statistical differences in certain morphological parameters were observed among the three groups of patients (P < 0.05). Compared with the OA and normal control groups, the HA group presented significant disparities in patellar thickness, patellar ligament length, the Insall ratio, the patellar lateral shift rate, the lateral patellar angle, and the patellofemoral index.

Conclusion

Compared with OA and normal individuals, Subjects with Haemophilia presented with smaller and thinner patellae, more significant patellar ligament contracture, reduced patellar height, and more pronounced patellar dislocation. Consequently, during total knee arthroplasty, we lean toward patellar reshaping in subjects with Haemophilia, exercise caution when considering patellar replacement, and, for those with severe preoperative patellar dislocation, perform intraoperative lateral retinacular release.

International Society on Thrombosis and Haemostasis Clinical Practice Guideline for Treatment of Congenital Haemophilia-A Critical Appraisal

INTRODUCTION

Evidence-based clinical practice guidelines drive optimal patient care and facilitate access to high-quality treatment. Creating guidelines for rare diseases such as haemophilia, where evidence does not often come from randomized controlled trials but from non-randomized and well-designed observational studies and real-world data, is challenging. The methodology used for assessing available evidence should consider this critical fact. In formulating guidelines, it is essential to include treatment goals and patient preference.

AIM

This paper comprehensively critiques, against this background, the recommendations of the ISTH clinical practice guidelines for the treatment of haemophilia.

METHODS

Each recommendation was critically reviewed against available evidence as well as existing guidelines and commented upon for its scientific validity, impact on clinical practice and access to care globally. The validity of the way in which the GRADE methodology was applied to existing evidence was also assessed.

RESULTS

The critique provided shows that these recommendations have major limitations: they did not state treatment goals and contradict existing guidelines; opportunities for providing access to innovation were missed when the therapeutic benefits of the products approved in the last decades were not included. A major reason for this is the inappropriate adoption of the GRADE methodology without adaptations and without considering treatment goals and patient-relevant outcomes.

CONCLUSION

These recommendations may mislead healthcare professionals, payers and governments and therefore cannot serve the patient community well. They setback the advances made in haemophilia care because they overlook important available evidence and do not guide clinical practice to contemporary standards.

Patient Experience With Efanesoctocog Alfa for Severe Hemophilia A: Results From the XTEND-1 Phase 3 Clinical Study Exit Interviews

PURPOSE

Hemophilia A is a rare bleeding disorder that leads to recurrent hemarthrosis, which can ultimately result in reduced mobility and poor quality of life. Qualitative exit interviews provide insights into patient perspectives and support the interpretation of quantitative trial data, such as patient-reported outcome measures. In the Phase 3 XTEND-1 study (NCT04161495) of efanesoctocog alfa in participants with severe hemophilia A, exit interviews were conducted to understand pre- and post-study experiences with pain and physical functioning and to evaluate participants' treatment experiences.

METHODS

In XTEND-1, participants (≥12 years old) received once-weekly efanesoctocog alfa prophylaxis 50 IU/kg for 52 weeks (Arm A) or on-demand efanesoctocog alfa 50 IU/kg for 26 weeks followed by 26 weeks once-weekly prophylaxis (50 IU/kg; Arm B). Optional qualitative exit interviews were conducted using a semi-structured guide in a subset of participants following study completion. Interviews included open-ended questions about participants' pre- and post-study experiences with hemophilia A and targeted questions relating to improvements in patient-reported outcomes assessed during XTEND-1, including the Haemophilia Quality of Life Questionnaire for Adults Physical Health subscale (Haem-A-QoL PH). Content validity of the Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Intensity 3a measure was also assessed, particularly the worst pain item.

FINDINGS

Exit interviews were conducted with 29 of 159 patients enrolled in XTEND-1 (mean [range] age 40 [16-73] years). Of 17 participants enrolled in Arm A, 13 (76.5%) reported a "wearing off" feeling with pre-study treatment, including more aches/pain, breakthrough bleeds, and limited physical activities. Joint pain was the most reported pre-study symptom (96.6%; n = 28/29), followed by a reduced ability to move without pain (89.7%, n = 26/29). Improvements following efanesoctocog alfa prophylaxis in ≥1 Haem-A-QoL PH domain were reported by 89.7% (n = 26/29) of participants, with improvements in joint pain, the ability to move without pain, and painful swellings reported by at least 21 (84%) participants. Participants reported that the PROMIS Pain Intensity 3a items were relevant, clear, and easy to answer. Most participants (96.6%) were "quite satisfied" or "very satisfied" with efanesoctocog alfa prophylaxis. All participants preferred efanesoctocog alfa over pre-study treatment.

IMPLICATIONS

The exit interviews demonstrated that once-weekly efanesoctocog alfa prophylaxis resulted in patient-relevant and meaningful improvements in pain and physical functioning, consistent with the quantitative findings from XTEND-1. These results support the validity of the Haem-A-QoL PH and PROMIS Pain Intensity 3a assessed during XTEND-1, demonstrating the potential for change with efficacious treatment.

TRIAL REGISTRY

ClinicalTrials.gov TRIAL REGISTRATION NUMBER: NCT04161495 REGISTRY URL: https://clinicaltrials.gov/study/NCT04161495.

Clinical validation and application of targeted long-range polymerase chain reaction and long-read sequencing-based analysis for hemophilia: experience from a hemophilia treatment center in China

BACKGROUND

Targeted long-read sequencing (LRS) is expected to comprehensively analyze diverse complex variants in hemophilia A (HA) and hemophilia B (HB) caused by the F8 and F9 genes, respectively. However, its clinical applicability still requires extensive validation.

OBJECTIVES

To evaluate the clinical applicability of targeted LRS-based analysis compared with routine polymerase chain reaction (PCR)-based methods.

METHODS

Gene variants of retrieved subjects were retrospectively and prospectively analyzed. Whole-genome sequencing was performed to further analyze undiagnosed cases. Breakpoints of novel genomic rearrangements were mapped and validated using long-distance PCR and long-range PCR combined with sequencing.

RESULTS

In total, 122 subjects were retrieved. In retrospective analysis of the 90 HA cases, HA-LRS assay showed consistent results in 84 cases compared with routine methods and characterized 6 large deletions with their exact breakpoints confirmed by further validation in 6 cases (routine methods only presented failure in amplifying the involved exons). In prospective analysis of the 21 HA subjects, 20 variants of F8 were identified in 20 cases. For the remaining HA patient, no duplication/deletion or single-nucleotide variant (SNV)/insertion and deletion (InDel) was found, but a potential recombination involving exons 14 and 21 of F8 was observed by LRS. Whole-genome sequencing analysis and further verification defined a 30 478 base pairs (bp) tandem repeat involving exons 14 to 21 of F8. Among the 11 HB patients, HB-LRS analysis detected 11 SNVs/InDels in F9, consistent with routine methods.

CONCLUSION

Targeted LRS-based analysis was efficient and comprehensive in identifying SNVs/InDels and genomic rearrangements of hemophilia genes, especially when we first expanded the panel to include F9. However, further investigation for complex gross rearrangement is still essential.

Expert Opinion for Defining a Severe Bleeding Phenotype to Guide Prophylaxis in Patients with Nonsevere Hemophilia

Prophylaxis is the standard of care for patients with severe hemophilia, patients with moderate hemophilia, or those with another congenital bleeding disorder that is associated with a severe bleeding phenotype and/or a high risk of spontaneous life-threatening bleeding. Patients with nonsevere hemophilia (factor VIII [FVIII] ≥ 1%) may also have a bleeding phenotype that requires prophylaxis. To date, however, there are no clear criteria as to when prophylaxis is indicated in these patients. Also, the term "severe bleeding phenotype (SBPT)" is neither included in the definitions of the International Society on Thrombosis and Haemostasis (ISTH) nor specified in the World Federation of Hemophilia (WFH) guidelines. Based on our personal experience and available evidence, we propose the criteria we use to define an SBPT and when we consider offering prophylaxis in patients with nonsevere hemophilia. Our proposals can be the basis for discussions in the community about the assessment of SBPT and the initiation of prophylaxis in patients with nonsevere hemophilia without inhibitors.

Prophylaxis with recombinant factor IX Fc fusion protein reduces the risk of bleeding and delays time to first spontaneous bleed event in previously untreated patients with haemophilia B: A post hoc analysis of the PUPs B-LONG study

OBJECTIVES

Haemophilia B (HB), characterised by deficient factor IX (FIX), leads to spontaneous bleeds. Severe cases require prophylactic FIX replacement. This post hoc analysis assessed the first spontaneous bleeds among previously untreated patients (PUPs) with HB treated with recombinant FIX Fc fusion protein (rFIXFc) (NCT02234310) to identify factors influencing bleeds.

METHODS

Subjects included paediatric PUPs with HB (≤2 IU/dL endogenous FIX). Analyses described treatment patterns (on demand [OD] vs. prophylaxis) and prophylaxis type (started on vs. switched to prophylaxis). Kaplan-Meier analyses assessed the time to first spontaneous bleed, including median time to event and fitting models with predictors for treatment regimen and/or baseline age.

RESULTS

PUPs B-LONG enrolled 33 subjects. Baseline age did not influence the time to first spontaneous bleed for any rFIXFc regimen. Those who started on prophylaxis with rFIXFc (n = 11), compared with those treated OD (n = 22), had an extended time to first spontaneous bleed. Starting prophylaxis afforded a 93% reduced risk of first spontaneous bleed versus starting OD (hazard ratio [95% confidence interval]: 0.071 [0.009-0.592]) (p = .015).

CONCLUSION

rFIXFc prophylaxis, particularly starting early, reduced the risk of bleeding and delayed time to first spontaneous bleed compared with rFIXFc OD. Hence, initial treatment regimens impact bleed patterns in paediatric PUPs.

Nonfactor Therapies in Hemophilia A: An Essential Drug Entity

Inequity in the access to effective therapies for rare diseases, such as hemophilia A, is a significant concern in resource-limited settings. Including necessary medications in the essential drug list can ensure that populations have access to safe and affordable treatments. Emicizumab, a nonfactor therapy, addresses many of the challenges associated with traditional factor replacement for hemophilia A, including frequent administration and the risk of inhibitor development. Studies in India show that emicizumab is cost-effective and clinically beneficial. The inclusion of emicizumab in the National Health Mission's (NHM) Essential Drug List (India) would improve treatment access and adherence, reduce healthcare burden, and improve outcomes for patients, particularly those with high bleeding rates and poor accessibility to care. Moreover, it will ensure the continuity of therapy for all existing patients who have been on emicizumab supported by the NHM in the last four years. This review aims to consolidate evidence regarding the current status of care and the benefits of emicizumab in India to highlight the importance of the addition of emicizumab to NHM's Essential Drug List.

Emicizumab and unmet needs of patients with hemophilia a who are managed with replacement therapies

INTRODUCTION

Hemophilia A is managed with coagulation clotting factor VIII (FVIII) therapy that poses significant challenges, such as a high treatment burden, immunogenicity, inconsistent hemostatic cover, poor treatment outcomes, and musculoskeletal progression despite adequate prophylactic treatment. Various non-factor therapies, such as several natural anticoagulant inhibitors and factor FVIII mimetics, have been developed to address these unmet needs. However, the role of emicizumab in addressing these unmet needs remains underexplored.

AREAS COVERED

This review delves into the evolution of hemophilia A replacement clotting therapy from plasma-derived products to recombinant products and, more recently, nonfactor therapies. It underscores the unmet needs of replacement therapy and explores the nonfactor therapies developed to address them. The review then comprehensively summarizes the clinical trial and real-world experience data, demonstrating how emicizumab tackles these unsatisfied demands.

EXPERT OPINION

Replacement clotting factor therapies as the standard of care has exposed several needs that have yet to be addressed. However, data from numerous emicizumab clinical trials and real-world experience offer a promising outlook, suggesting that it may effectively address many unmet needs. As hemophilia treatment goals continue to evolve, the role of currently developed nonfactor therapies in hemophilia management is yet to be fully defined.

Future needs for continuing innovation in hemophilia: improving outcomes for individuals of all severities, including women and those in resource-constrained regions

Over recent decades, management of people with hemophilia (PwH) has been greatly improved by scientific advances that have resulted in a rich and varied therapeutic landscape. Nevertheless, treatment limitations continue to drive innovation, and emerging options have the potential to realize further improvement. We advocate four general principles to optimize benefits from innovation: individualizing the treatment approach, targeting 'normal,' making the most of available resources, and considering treatment affordability. Ultimately, all PwH-men and women, of all ages and severities, and worldwide-should have access to treatment that fully prevents bleeding, while allowing personal, social, family, and professional lives of choice. Clearly, we are not there yet, but developing goals/milestones based on the principles we describe may help to achieve this.

Gene Therapy with Fidanacogene Elaparvovec in Adults with Hemophilia B

BACKGROUND

Fidanacogene elaparvovec, an adeno-associated virus (AAV) gene-therapy vector for hemophilia B containing a high-activity human factor IX variant (FIX-R338L/FIX-Padua), was associated with sustained factor IX activity in a phase 1-2a study.

METHODS

We conducted a phase 3 open-label study of fidanacogene elaparvovec at a dose of 5×1011 vector genome copies per kilogram of body weight. Men 18 to 65 years of age with hemophilia B and a factor IX level of 2% or less were eligible for screening if they had received at least 6 months of therapy with prophylactic factor IX concentrate. The primary end point, tested for noninferiority, was the annualized bleeding rate (treated and untreated bleeding episodes) from week 12 to month 15 after treatment with fidanacogene elaparvovec as compared with the prophylaxis lead-in period. Superiority, additional efficacy end points, and safety were also assessed.

RESULTS

Of 316 men who underwent screening for the lead-in study, 204 (64.6%) were not eligible; 188 (59.5%) of those were ineligible owing to the presence of anti-AAV neutralizing antibodies. Of the 45 participants who received fidanacogene elaparvovec, 44 completed at least 15 months of follow-up. The annualized rate of bleeding for all bleeding episodes decreased by 71%, from 4.42 (95% confidence interval [CI], 1.80 to 7.05) at baseline to 1.28 (95% CI, 0.57 to 1.98) after gene therapy, a treatment difference of -3.15 episodes (95% CI, -5.46 to -0.83; P = 0.008). This result shows the noninferiority and superiority of fidanacogene elaparvovec to prophylaxis. At 15 months, the mean factor IX activity was 26.9% (median, 22.9%; range, 1.9 to 119.0) by one-stage SynthASil assay. A total of 28 participants (62%) received glucocorticoids for increased aminotransferase levels or decreased factor IX levels (or both) starting between 11 and 123 days. No infusion-related serious adverse events, thrombotic events, development of factor IX inhibitors, or malignant conditions were observed.

CONCLUSIONS

Fidanacogene elaparvovec was superior to prophylaxis for the treatment of participants with hemophilia B, leading to reduced bleeding and stable factor IX expression. (Funded by Pfizer; BENEGENE-2 ClinicalTrials.gov number, NCT03861273.).

Perioperative Management for Port Catheter Procedures in Pediatric Patients with Severe Hemophilia and Inhibitors

BACKGROUND

 The objective of this systematic study was to assess the perioperative management and outcome of surgery in pediatric patients with hemophilia A/B and inhibitors compared to nonhemophilic pediatric patients.

METHODS

 The surgical outcome of 69 port catheter operations in patients with hemophilia who developed inhibitory antibodies against the administered factor was compared to 51 procedures in the control group. In the patients with hemophilia and inhibitors, a standardized protocol for recombinant activated factor VII was used to prevent perioperative bleeding.

RESULTS

 Hemophilic pediatric patients with inhibitors showed no significant differences in perioperative management (blood transfusion: p = 0.067, duration of surgery: p = 0.69; p = 0.824) in comparison to patients without hemophilia. The length of hospital stay was significantly longer in pediatric patients with hemophilia and inhibitors (20 days vs. 4 days for insertion; 12 days vs. 1 day for explantation). Moreover, no statistically significant difference was found for secondary bleeding (three patients with hemophilia vs. none in the control group; p = 0.11) or surgical complications (five hemophilia patients vs. none with grade I complication; one hemophilia patient vs. none with grade II complications; p = 0.067).

CONCLUSION

 This study has demonstrated that port catheter insertion and removal is safe in these patients. Moreover, it shows the importance of a coordinated approach with a multidisciplinary team.

Assessment of joint health in patients receiving prophylaxis for haemophilia A: a cross-sectional survey in five European countries

OBJECTIVES

To evaluate joint health, pain and health-related quality of life (HRQoL) in patients with moderate/severe haemophilia A in Europe.

DESIGN

Multinational, cross-sectional survey, with retrospective data collection. Data were taken from the Adelphi Real World Haemophilia Disease Specific Programme Wave II, using surveys completed by physicians and patients between February 2020 and May 2021.

SETTING

Haematologists/haemato-oncologists and their patients in France, Germany, Italy, Spain and the UK.

PARTICIPANTS

Males aged ≥18 years with moderate or severe haemophilia A (baseline clotting factor level ≤5%), without existing inhibitors and currently receiving prophylaxis. Patients were grouped into those with or without haemophilia-affected joints (HAJs) based on bleeding, radiographic, surgical, mobility and joint pain data.

PRIMARY OUTCOME MEASURE

Characterisation of humanistic and clinical outcomes in patients with or without HAJs.

RESULTS

A total of 120 physicians provided data for 351 eligible patients; 209 (59.5%) patients had HAJs and 142 (40.5%) had no HAJs. Pain/discomfort was significantly different (p=0.01) and reported more frequently in the HAJ (85.7%) vs non-HAJ group (53.3%). Pain medication use was significantly higher in the HAJ versus non-HAJ group (73.2% vs 60.6%; p=0.01). Up to half of the patients with HAJs had synovitis (49.8%) or arthropathy (48.4%), and one-third had undergone joint surgery (35.4%). Overall health status was significantly worse in the HAJ versus non-HAJ group (mean (SD) EuroQol Visual Analogue Scale score: 65.5 (19.3) vs 81.1 (14.6); p=0.01).

CONCLUSIONS

In this multinational real-world study, nearly two-thirds of adults with moderate/severe haemophilia A without inhibitors experienced HAJs despite prophylaxis. Individuals with HAJs had higher rates of pain and pain medication use, and lower HRQoL compared with those without HAJs. These data indicate that HAJs represent a clinically relevant burden and early identification/monitoring and management of affected joints should be an important consideration to help prevent long-term joint morbidity.

Moving towards Normalization of haemostasis and health equity: Evolving treatment goals for haemophilia A

BACKGROUND

Treatment options for people with haemophilia are evolving at a rapid pace and a range of prophylactic treatment options using various technologies are currently available, each with their own distinct safety and efficacy profile.

TREATMENT GOALS

The access to replacement therapy and prophylaxis has driven a dramatic reduction in mortality and resultant increase in life expectancy. Beyond this, the abolition of bleeds and preservation of joint health represent the expected, but rarely attained, goals of haemophilia treatment and care. These outcomes also do not address the complexity of health-related quality of life impacted by haemophilia and its treatment.

CONCLUSION

Capitalizing on the major potential of therapeutic innovations, 'Normalization' of haemostasis, as a concept, should include the aspiration of enabling individuals to live as normal a life as possible, free from haemophilia-imposed limitations. To achieve this-being supported by the data reviewed in this manuscript-the concept of haemostatic and life Normalization needs to be explored and debated within the wider multidisciplinary teams and haemophilia community.

Joint health and pain in the changing hemophilia treatment landscape

INTRODUCTION

Hemophilia is an inherited bleeding disorder. Bleeding, and in particular joint hemorrhage results in chronic arthropathy and disability. Acute and chronic pain are frequent and limit activity and participation and result in decreased health-related quality of life. Remarkable progress has been made in the diagnosis and treatment of hemophilia but bleeding continues to prove recalcitrant to currently available treatments and joint disease remains problematic. Physiotherapy and pain management are mainstays of current multidisciplinary integrated care of people with hemophilia (PWH). The focus of this review is on preservation of joint health in the era of new and innovative therapies.

AREAS COVERED

A search of the PubMed Central was conducted on 1 February 2024 using the MeSH Major Topic terms identified as keywords for the manuscript. This review will highlight what is known and unknown about joint bleeding and arthropathy, including insights on pain as a related complication.

EXPERT OPINION

Recent advances in therapeutic interventions aimed at promoting healthy joints in PWH will be discussed, including both the pharmacological treatment landscape and related strategies to promote joint health.

Shifting Paradigms and Arising Concerns in Severe Hemophilia A Treatment

The management of hemophilia A has undergone a remarkable revolution, in line with technological advancement. In the recent past, the primary concern associated with Factor VIII (FVIII) concentrates was the risk of infections, which is now almost resolved by advanced blood screening and viral inactivation methods. Improving patients' compliance with prophylaxis has become a key focus, as it can lead to improved health outcomes and reduced health care costs in the long term. Recent bioengineering research is directed toward prolonging the recombinant FVIII (rFVIII) coagulant activity and synthesising higher FVIII yields. As an outcome, B-domain deleted, polyethylene glycolated, single-chain, Fc-fused rFVIII, and rFVIIIFc-von Willebrand Factor-XTEN are available for patients. Moreover, emicizumab, a bispecific antibody, is commercially available, whereas fitusiran and tissue factor pathway inhibitor are in clinical trial stages as alternative strategies for patients with inhibitors. With these advancements, noninfectious complications, such as inhibitor development, allergic reactions, and thrombosis, are emerging concerns requiring careful management. In addition, the recent approval of gene therapy is a major milestone toward a permanent cure for hemophilia A. The vast array of treatment options at our disposal today empowers patients and providers alike, to tailor therapeutic regimens to the unique needs of each individual. Despite significant progress in modern treatment options, these highly effective therapies are markedly more expensive than conventional replacement therapy, limiting their access for patients in developing countries.

Adult People with Hemophilia A Have Low Annualized Bleeding Rate, However the Arthropathy Remains a Burden: A Retrospective Cohort Study

Congenital Hemophilia A is a complex disease to treat, especially in places without access to hemophilia treatment centers (HTCs). The primary aim of this study was to analyze the outcomes of a cohort of adult people with congenital hemophilia A in an HTC localized in the Bajio region of Mexico. Observational retrospective study of a cohort of 82 adult people with congenital hemophilia A treated in a tertiary-level hospital in the Bajio region of Mexico, between June 2022 and June 2023. The median age of the patients was 29.5 years, 60.9% with severe hemophilia A, 53.6% were under some factor VIII prophylaxis regimen, and 52.4% had home therapy. The median annualized bleeding rate (ABR) was one bleed/year (IQR 0-3 bleeds/year) including a median of zero joint bleeds/year (IQR 0-3 bleeds/year). The presence of high-response inhibitors was detected in 8.5%, with an overall incidence of inhibitors of 14.6% of the cohort. Univariate analysis showed that inhibitors (OR 21.10; CI 95% 1.20-370.3; P = 0.03) and clinical arthropathy (OR 6.14; CI 95% 2.13-17.68; P = 0.001) were significantly higher in severe hemophilia. Clinically significant arthropathy was found in 71.9% of patients. Ultrasonography of the target joints showed that mainly cartilage degeneration was affected. Blood transfusion-associated viral infections were detected in 10.9% of patients. In our HTC, current treatment with hemostatic agents allows adequate control of ABR with acceptable inhibitor rates. However, we still have joint damage in most patients, which is partly explained by the fact that prophylaxis was introduced only in recent years.

Evaluating Factor VIII Concentrates Using Clot Waveform Analysis

Background/Objectives: FVIII reagent activity varies across different assays, as well as activated partial thromboplastin time (APTT) reagents. The hemostatic ability of various FVIII reagents was examined via clot waveform analysis (CWA). Methods: APTT was measured using 12 APTT reagents, a small amount of tissue factor-induced FIX activation (sTF/FIXa) and a small amount of thrombin time (sTT) in order to examine 10 FVIII reagents and reference plasma (RP) using CWA. FVIII activity was measured using CWA-APTT, a chromogenic assay, or CWA-sTT. Results: Although the peak time (PT) and peak height (PH) of the CWA-APTT were markedly different in different FVIII reagents using several APTT reagents, the PTs of CWA-APTT were generally normal or shortened and the PHs of CWA-APTT were generally lower than those of RP. The FVIII activity varied, as evaluated using APTT, and was higher when using the CWA-sTT method than the APTT or chromogenic methods. CWA-sTT showed an elevated second peak of first DPH in all FVIII reagents, and both CWA-sTF/FIXa and CWA-sTT were enhanced using APTT reagents. Conclusions: Our evaluation of the hemostatic ability of FVIII reagents varied among APTT reagents. CWA-sTT can be used to further evaluate the hemostatic ability of an FVIII concentrate based on thrombin burst.

AAV mediated repression of Neat1 lncRNA combined with F8 gene augmentation mitigates pathological mediators of joint disease in haemophilia

Haemophilic arthropathy (HA), a common comorbidity in haemophilic patients leads to joint pain, deformity and reduced quality of life. We have recently demonstrated that a long non-coding RNA, Neat1 as a primary regulator of matrix metalloproteinase (MMP) 3 and MMP13 activity, and its induction in the target joint has a deteriorating effect on articular cartilage. In the present study, we administered an Adeno-associated virus (AAV) 5 vector carrying an short hairpin (sh)RNA to Neat1 via intra-articular injection alone or in conjunction with systemic administration of a capsid-modified AAV8 (K31Q) vector carrying F8 gene (F8-BDD-V3) to study its impact on HA. AAV8K31Q-F8 vector administration at low dose, led to an increase in FVIII activity (16%-28%) in treated mice. We further observed a significant knockdown of Neat1 (~40 fold vs. untreated injured joint, p = 0.005) in joint tissue of treated mice and a downregulation of chondrodegenerative enzymes, MMP3, MMP13 and the inflammatory mediator- cPLA2, in mice receiving combination therapy. These data demonstrate that AAV mediated Neat1 knockdown in combination with F8 gene augmentation can potentially impact mediators of haemophilic joint disease.

Aberrant methylation and expression of TNXB promote chondrocyte apoptosis and extracullar matrix degradation in hemophilic arthropathy via AKT signaling

Recurrent joint bleeding in hemophilia patients frequently causes hemophilic arthropathy (HA). Drastic degradation of cartilage is a major characteristic of HA, but its pathological mechanisms has not yet been clarified. In HA cartilages, we found server matrix degradation and increased expression of DNA methyltransferase proteins. We thus performed genome-wide DNA methylation analysis on human HA (N=5) and osteoarthritis (OA) (N=5) articular cartilages, and identified 1228 differentially methylated regions (DMRs) associated with HA. Functional enrichment analyses revealed the association between DMR genes (DMGs) and extracellular matrix (ECM) organization. Among these DMGs, Tenascin XB (TNXB) expression was down-regulated in human and mouse HA cartilages. The loss of Tnxb in F8-/- mouse cartilage provided a disease-promoting role in HA by augmenting cartilage degeneration and subchondral bone loss. Tnxb knockdown also promoted chondrocyte apoptosis and inhibited phosphorylation of AKT. Importantly, AKT agonist showed chondroprotective effects following Tnxb knockdown. Together, our findings indicate that exposure of cartilage to blood leads to alterations in DNA methylation, which is functionally related to ECM homeostasis, and further demonstrate a critical role of TNXB in HA cartilage degeneration by activating AKT signaling. These mechanistic insights allow development of potentially new strategies for HA cartilage protection.

Fitusiran prophylaxis in people with hemophilia A or B who switched from prior BPA/CFC prophylaxis: the ATLAS-PPX trial

ABSTRACT

Fitusiran, a subcutaneous investigational small interfering RNA therapeutic, targets antithrombin to rebalance hemostasis in people with hemophilia A or B (PwHA/B), irrespective of inhibitor status. This phase 3, open-label study evaluated the efficacy and safety of fitusiran prophylaxis in males aged ≥12 years with hemophilia A or B, with or without inhibitors, who received prior bypassing agent (BPA)/clotting factor concentrate (CFC) prophylaxis. Participants continued their prior BPA/CFC prophylaxis for 6 months before switching to once-monthly 80 mg fitusiran prophylaxis for 7 months (onset and efficacy periods). Primary end point was annualized bleeding rate (ABR) in the BPA/CFC prophylaxis and fitusiran efficacy period. Secondary end points included spontaneous ABR (AsBR) and joint ABR (AjBR). Safety and tolerability were assessed. Of 80 enrolled participants, 65 (inhibitor, n = 19; noninhibitor, n = 46) were eligible for ABR analyses. Observed median ABRs were 6.5 (interquartile range [IQR], 2.2-19.6)/4.4 (IQR, 2.2-8.7) with BPA/CFC prophylaxis vs 0.0 (IQR, 0.0-0.0)/0.0 (IQR, 0.0-2.7) in the corresponding fitusiran efficacy period. Estimated mean ABRs were substantially reduced with fitusiran by 79.7% (P = .0021) and 46.4% (P = .0598) vs BPA/CFC prophylaxis, respectively. Forty-one participants (63.1%) experienced 0 treated bleeds with fitusiran vs 11 (16.9%) with BPAs/CFCs. Median AsBR and AjBR were both 2.2 with BPA/CFC prophylaxis and 0.0 in the fitusiran efficacy period. Two participants (3.0%) experienced suspected or confirmed thromboembolic events with fitusiran. Once-monthly fitusiran prophylaxis significantly reduced bleeding events vs BPA/CFC prophylaxis in PwHA/B, with or without inhibitors, and reported adverse events were generally consistent with previously identified risks of fitusiran. This trial was registered at www.ClinicalTrials.gov as #NCT03549871.

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.

Predicting joint involvement through tailored prophylaxis in severe haemophilia A, is it possible?

INTRODUCTION

Tailored prophylaxis is the current treatment regimen for patients with severe haemophilia A. Recently, published guidelines describe two possible approaches, based on clinical characteristics or estimation of pharmacokinetic parameters. However, both have strengths and weaknesses, and their characteristics need to be integrated to optimize treatment appropriately. In this paper, we present a model that considers together the characteristics of prophylaxis and the relevance of each.

METHODS

The age at initiation of prophylaxis, number of bleeding events, treatment regimen, therapeutic adherence, FVIII trough levels, and joint status were analyzed in 59 patients followed at La Paz University Hospital between January 2000 and December 2019.

RESULTS

The mean duration of primary prophylaxis of 113.37 ± 57.79 months. Eighty-three percent (n = 49) had no joint status involvement at the end of follow-up (HJHS and HEAD-US = 0). The median ABR was 0.7 (IQR 0.2 -1.0) and 54.2% presented trough levels of FVIII during follow-up >1 IU/dL. 72,9% engaged in some type of physical activity and overall adherence was over 85% in all patients evaluated. The regression analysis performed, considering all these factors, showed that the initiation of prophylaxis before 21 months of age was the most relevant protective factor against the appearance of joint involvement (OR 88.33 p.031 CI 95% 1.49-5224.40) CONCLUSION: Early initiation of prophylaxis was the most relevant factor in the protection of joint status. More comprehensive analysis models adapted to the characteristics of each population, are needed to adequately individualize treatment.

Consensus-Based Expert Recommendations on the Management of Hemophilia A in the Gulf Region

BACKGROUND

Hemophilia A presents a significant health challenge in the Gulf region, where it has an especially high prevalence. There are several unmet needs associated with the management of hemophilia A in the region. The aim of this manuscript was to contextualize unmet management needs, provide recommendations to optimize care, and specify requirements for the establishment of gene therapy centers in the region.

SUMMARY

An expert panel was assembled comprising ten clinical hematologists from Kuwait, Oman, Saudi Arabia, and the UAE. The Delphi methodology was used to obtain a consensus on statements relating to several aspects of hemophilia A. A consensus was reached for all statements by means of an online, anonymized voting system. The consensus statements pertain to screening and diagnosis, treatment approaches, and requirements for the implementation of gene therapy.

KEY MESSAGES

There are significant challenges that hinder the optimal management of hemophilia A in the Gulf region. The consensus statements presented provide specific recommendations to improve diagnostic and treatment approaches, promote multidisciplinary care, and optimize regional data generation and reporting. These statements also delineate the requirements for the establishment of gene therapy centers for hemophilia A in the region.

BACKGROUND

Hemophilia A presents a significant health challenge in the Gulf region, where it has an especially high prevalence. There are several unmet needs associated with the management of hemophilia A in the region. The aim of this manuscript was to contextualize unmet management needs, provide recommendations to optimize care, and specify requirements for the establishment of gene therapy centers in the region.

SUMMARY

An expert panel was assembled comprising ten clinical hematologists from Kuwait, Oman, Saudi Arabia, and the UAE. The Delphi methodology was used to obtain a consensus on statements relating to several aspects of hemophilia A. A consensus was reached for all statements by means of an online, anonymized voting system. The consensus statements pertain to screening and diagnosis, treatment approaches, and requirements for the implementation of gene therapy.

KEY MESSAGES

There are significant challenges that hinder the optimal management of hemophilia A in the Gulf region. The consensus statements presented provide specific recommendations to improve diagnostic and treatment approaches, promote multidisciplinary care, and optimize regional data generation and reporting. These statements also delineate the requirements for the establishment of gene therapy centers for hemophilia A in the region.

Which patients should be considered for gene therapy

Gene therapy for haemophilia, utilizing adeno-associated viral vectors (AAVs) and coagulation factor genes, have demonstrated promising results, leading to recent approvals and introduction of the first gene therapy products into clinical practice. For successful and safe use, there are predefined inclusion and exclusion criteria, and the treatment process and associated risks should be thoroughly understood and long-term safety and efficacy carefully evaluated during follow up. As gene therapy becomes more accessible outside of clinical study centers, continuous evaluation of patient eligibility for subsequent AAV-based treatments becomes essential. Thorough evaluation of factors such as liver condition, anti-AAV status, and medical history ensures that gene therapy maximizing benefits while minimizing risks. Apart from fulfilling the established inclusion and exclusion criteria, the success of gene therapy is greatly influenced by the motivation and willingness of patients to accept temporary constraints, such as regular laboratory monitoring, potential use of immunosuppressants, and thorough documentation. Furthermore, various patient-related factors play a significant role in the management and outcomes of gene therapy, making a comprehensive evaluation essential. With the accumulation of more data, there is potential for the expansion of certain inclusion criteria, which may allow for a larger number of eligible patients to benefit from gene therapy. Empowering patients through shared decision-making enables them to thoroughly consider the therapy's potential benefits and risks.

AAV gene therapy in companion dogs with severe hemophilia: Real-world long-term data on immunogenicity, efficacy, and quality of life

The hemophilias are the most common severe inherited bleeding disorders and are caused by deficiency of clotting factor (F) VIII (hemophilia A) or FIX (hemophilia B). The resultant bleeding predisposition significantly increases morbidity and mortality. The ability to improve the bleeding phenotype with modest increases in clotting factor levels has enabled the development and regulatory approval of adeno-associated viral (AAV) vector gene therapies for people with hemophilia A and B. The canine hemophilia model has proven to be one of the best predictors of therapeutic response in humans. Here, we report long-term follow-up of 12 companion dogs with severe hemophilia that were treated in a real-world setting with AAV gene therapy. Despite more baseline bleeding than in research dogs, companion dogs demonstrated a 94% decrease in bleeding rates and 61% improvement in quality of life over a median of 4.1 years (range 2.6-8.9). No new anti-transgene immune responses were detected; one dog with a pre-existing anti-FVIII inhibitor achieved immune tolerance with gene therapy. Two dogs expressing 1%-5% FVIII post gene therapy experienced fatal bleeding events. These data suggest AAV liver-directed gene therapy is efficacious in a real-world setting but should target expression >5% and closely monitor those with levels in the 1%-5% range.

Six-Year, Real-World Use of Prophylaxis with Recombinant Factor IX-Albumin Fusion Protein (rIX-FP) in Persons with Hemophilia B: A Single-Center Retrospective-Prospective Study

Background: Extended half-life (EHL) factor IX (FIX) concentrates allow for prophylaxis with prolonged dosing intervals and high bleeding protection in persons with hemophilia B. Long-term real-world studies are lacking. Methods: In a retrospective-prospective study, the six-year use of prophylaxis with the EHL recombinant FIX-albumin fusion protein (rIX-FP) was analyzed, comparing outcomes with previous standard half-life (SHL) FIX in patients already on prophylaxis. Results: Prophylaxis with rIX-FP was prescribed in 15 patients (10 severe, 5 moderate; follow-up: 57 ± 17 months). Based on a pharmacokinetic assessment and clinical needs, the first regimen was 47 ± 7 IU/Kg every 9 ± 2 days. All but one patient remained on rIX-FP prophylaxis, adjusting infusion frequency and/or dose; the last prescribed frequency was ≥10 days in 10/13 patients, being reduced in seven and increased in four vs. the first regimen. The weekly FIX dose was unchanged; FIX trough levels were >5% in all patients. The annual infusion number and FIX IU/Kg significantly decreased (~60%) in eight patients previously on SHL FIX prophylaxis, with similar concentrate costs. Very low bleeding rates (most traumatic bleeds and the last quartile of the infusion interval), improved orthopedic and pain scores, unchanged HEAD-US scores and problem joints, and high treatment adherence (>90%) and satisfaction were registered. Conclusions: Personalized, carefully adjusted rIX-FP regimens contribute to the diffusion and optimization of prophylaxis in persons with severe and moderate hemophilia B, with long-term favorable bleeding, joint, and patient-reported outcomes.

Safety and efficacy of damoctocog alfa pegol prophylaxis in patients with severe haemophilia A: Results of an interventional, post-marketing study

INTRODUCTION

Damoctocog alfa pegol (BAY 94-9027, Jivi® ) is an approved extended half-life factor VIII (FVIII) for treatment of previously treated patients with haemophilia A aged ≥12 years. We report the final results of an interventional, post-marketing study of damoctocog alfa pegol prophylaxis in patients with severe haemophilia A.

METHODS

In this open-label, interventional, post-marketing, phase 4 trial (NCT04085458), previously FVIII-treated patients with severe haemophilia A aged ≥18 years received damoctocog alfa pegol for ≥100 exposure days (EDs). Patients initially received 45 IU/kg every 5 days (recommended) or 40 IU/kg twice-weekly. At Visit 3, patients' doses could be increased, or treatment frequency adapted. The primary endpoint was FVIII inhibitor development (titre ≥.6 Bethesda units). Secondary endpoints included anti-polyethylene glycol (PEG) antibody development, treatment-emergent adverse events (AEs) and annualized bleeding rate (ABR).

RESULTS

Overall, 36 patients were enrolled; 32 patients received treatment, of whom, 27 completed the study. No patients developed FVIII inhibitors; three tested transiently positive for low-titre anti-PEG antibodies without clinical relevance. Three patients reported study-drug-related AEs of mild or moderate intensity. Two patients discontinued the study due to AEs. No deaths occurred. Most patients (70%) were treated with E5D/E7D regimens. The median (Q1;Q3) total ABR (N = 30) was 3.0 (.0;9.0) pre-study and 1.8 (.7;5.9) during the study.

CONCLUSION

Damoctocog alfa pegol individualized prophylaxis regimens were well-tolerated with no immunogenicity concerns. ABRs improved following the switch from pre-study prophylaxis to damoctocog alfa pegol prophylaxis. These results support the favourable safety and efficacy profile of damoctocog alfa pegol prophylaxis.

Expert United Kingdom consensus on the preservation of joint health in people with moderate and severe haemophilia A: A modified Delphi panel

AIM

For people with haemophilia A (PwHA), bleeding in the joints leads to joint damage and haemophilia-related arthropathy, impacting range of motion and life expectancy. Existing guidelines for managing haemophilia A support healthcare professionals (HCPs) and PwHA in their efforts to preserve joint health. However, such guidance should be reviewed, considering emerging evidence and consensus as presented in this manuscript.

METHODS

Fifteen HCPs experienced in the management of PwHA in the UK participated in a three-round Delphi panel. Consensus was defined at ≥70% of panellists agreeing or disagreeing for Likert-scale questions, and ≥70% selecting the same option for multiple- or single-choice questions. Questions not reaching consensus were revised for the next round.

RESULTS

26.8% (11/41), 44.8% (13/29) and 93.3% (14/15) of statements reached consensus in Rounds 1, 2 and 3, respectively. HCPs agreed that prophylaxis should be offered to patients with a baseline factor VIII (FVIII) level of ≤5 IU/dL and that, where there is no treatment burden, the aim of prophylaxis should be to achieve a trough FVIII level ≥15 IU/dL and maintain a longer period with FVIII levels of ≥20-30 IU/dL to provide better bleed protection. The aspirational goal for PwHA is to prevent all joint bleeds, which may be achieved by maintaining normalised (50-150 IU/dL) FVIII levels.

CONCLUSION

The panel of experts were largely aligned on approaches to preserving joint health in PwHA, and this consensus may help guide HCPs.

Physical activity and factor VIII levels in patients with haemophilia: A real-world prospective observational study

INTRODUCTION

Regular physical activity (PA) is recommended for patients with haemophilia (PwH). For PwH it is crucial to ensure a sufficient factor level to prevent PA-induced bleedings. However, there is a gap in the literature dealing with specific factor levels, which are needed when performing specific types of PA.

AIM

To provide data on factor VIII (FVIII) levels at the start of PA performed by PwH.

METHODS

In this prospective 12-month real-world observational study, 23 PwH recorded every PA they performed and the FVIII levels at the start of the PA using a pharmacokinetic application. PA types were clustered according to the collision and injury risk into three categories (Cat I = low, Cat II = medium, Cat III = high risk). Haemophilia Joint Health Scores (HJHS) were performed at baseline, after 6 and 12 months.

RESULTS

795 PA sessions of Cat I, 193 of Cat II, and 23 of Cat III were documented. FVIII levels at the start of PA were different between categories (Cat I: 29.8 ± 32.1%, Cat II: 38.3 ± 33.4%, Cat III: 86.6 ± 29.2%). Out of all PA sessions, 145 (14%) were performed at a factor level of ≤3%. Three PA-induced bleeding occurred. Baseline HJHS was 14.5 ± 13.6 points and did not change throughout the study.

CONCLUSION

This study provides real-life data on FVIII levels at the start of 1011 PA sessions. PwH are mainly active in low-risk sports with higher FVIII levels observed in Cat II and III, respectively. Only three PA-induced bleeding occurred, even though several PA were started with low FVIII levels.

Nothing short of a revolution: Novel extended half-life factor VIII replacement products and non-replacement agents reshape the treatment landscape in hemophilia A

Hemophilia A, an X-linked genetic disorder, is characterized by a deficiency or dysfunction of clotting Factor VIII. The treatment landscape has substantially changed by introducing novel extended half-life factor VIII (EHL-FVIII) replacement therapies such as efanesoctocog Alfa and non-factor replacement therapy such as emicizumab. These agents signal a shift from treatments requiring multiple weekly infusions to advanced therapies with long half-lives, offering superior protection against bleeding and improving patient adherence and quality of life. While EHL-FVIII treatment might lead to inhibitor development in some patients, non-factor replacement therapy carries thrombotic risks. Therefore, ongoing research and the generation of robust clinical evidence remain vital to guide the selection of optimal and cost-effective first-line therapies for hemophilia A patients.

Pharmacokinetic-Pharmacodynamic Modelling in Hemophilia A: Relating Thrombin and Plasmin Generation to Factor VIII Activity After Administration of a VWF/FVIII Concentrate

BACKGROUND

Hemophilia A patients are treated with factor (F) VIII prophylactically to prevent bleeding. In general, dosage and frequency are based on pharmacokinetic measurements. Ideally, an alternative dose adjustment can be based on the hemostatic potential, measured with a thrombin generation assay (TGA), like the Nijmegen hemostasis assay.

OBJECTIVE

The objective of this study was to investigate the predicted performance of a previously developed pharmacokinetic-pharmacodynamic model for FVIII replacement therapy, relating FVIII dose and FVIII activity levels with thrombin and plasmin generation parameters.

METHODS

Pharmacokinetic and pharmacodynamic measurements were obtained from 29 severe hemophilia A patients treated with pdVWF/FVIII concentrate (Haemate P®). The predictive performance of the previously developed pharmacokinetic-pharmacodynamic model was evaluated using nonlinear mixed-effects modeling (NONMEM). When predictions of FVIII activity or TGA parameters were inadequate [median prediction error (MPE) > 20%], a new model was developed.

RESULTS

The original pharmacokinetic model underestimated clearance and was refined based on a two-compartment model. The pharmacodynamic model displays no bias in the observed normalized thrombin peak height and normalized thrombin potential (MPE of 6.83% and 7.46%). After re-estimating pharmacodynamic parameters, EC50 and Emax values were relatively comparable between the original model and this group. Prediction of normalized plasmin peak height was inaccurate (MPE 58.9%).

CONCLUSION

Our predictive performance displayed adequate thrombin pharmacodynamic predictions of the original model, but a new pharmacokinetic model was required. The pharmacodynamic model is not factor specific and applicable to multiple factor concentrates. A prospective study is needed to validate the impact of the FVIII dosing pharmacodynamic model on bleeding reduction in patients.

A post hoc comparative real-world analysis of HEAD-US score for joint health assessment of patients with severe haemophilia A and B in Spain

AIM

Joint damage due to haemarthrosis can be effectively monitored with point-of care ultrasound using the Haemophilia Early Arthropathy Detection with US (HEAD-US) scoring system. A post hoc comparative analysis of the joint status of patients with severe haemophilia A (HA) or B (HB) was performed.

METHODS

The databases of two observational, cross-sectional studies that recruited patients with HA or HB from 12 Spanish centres were analysed to compare the status of the elbows, knees and ankles in patients with severe disease according to treatment modality. The HEAD-US score was calculated in both studies by the same trained operators.

RESULTS

Overall, 95 HA and 41 HB severe patients were included, with a mean age of 35.2 ± 11.8 and 32.7 ± 14.2 years, respectively. The percentage of patients who received prophylaxis, over on-demand (OD) treatment, was much higher in HA (91.6%) than in HB (65.8%) patients. With a similar number of target joints, the HEAD-US score was zero in 6.3% HA and 22.0% HB patients (p < .01), respectively. The HA population showed significantly worse HEAD-US scores. Whilst osteochondral damage occurred more frequently in patients OD or tertiary prophylaxis, our data suggest that articular damage is less prominent in primary/secondary prophylaxis, regardless of the type of haemophilia. These latter treatment modalities were also associated with a lower prevalence of synovial hypertrophy, particularly in HB patients.

CONCLUSION

This post hoc analysis indicates that joint status seems to be significantly influenced by haemophilia type (HA or HB) and treatment modality in these severe Spanish populations with severe disease. Continuing HEAD-US monitoring for the early detection and management of intra-articular abnormalities, as well as more efficiently tailored therapies should be warranted.

The effectiveness and safety of octocog alfa in patients with hemophilia A: up to 7-year follow-up of the real-world AHEAD international study

Background

Real-world data assessing treatment outcomes in patients with hemophilia A in routine clinical practice are limited.

Objective

To evaluate the effectiveness and safety of octocog alfa in patients with moderate/severe hemophilia A receiving treatment in clinical practice.

Design

The international Antihemophilic Factor Hemophilia A Outcome Database study is an observational, noninterventional, prospective, multicenter study.

Methods

This planned interim data read-out was conducted following 7 years of observation of patients receiving octocog alfa (cut-off, 30 June 2020). The primary endpoint was joint health status, assessed by the Gilbert Score. Secondary endpoints included annualized bleeding rates (ABRs), Hemophilia Joint Health Score (HJHS), health-related quality of life, consumption, and safety. This post hoc analysis stratified data by hemophilia severity at baseline [moderate, factor VIII (FVIII) 1-5%; severe, FVIII <1%].

Results

Of the 711 patients in this analysis, 582 (82%) were receiving prophylaxis with octocog alfa at enrollment, and 498 (70%) had severe disease. Median Gilbert Scores were higher with on-demand therapy versus prophylaxis and scores were comparable in moderate and severe disease. In patients receiving prophylaxis, there was an improvement in HJHS Global Gait Score over 7 years of follow-up overall and in patients with severe disease. ABRs and annualized joint bleeding rates were low across all 7 years. An ABR of zero was reported in 34-56% of prophylaxis patients versus 20-40% in the on-demand group. ABRs were similar in severe and moderate disease. In total, 13/702 (1.9%) patients experienced 18 treatment-related adverse events.

Conclusion

These data demonstrate the long-term effectiveness and safety of octocog alfa in patients with moderate and severe hemophilia A, especially in those receiving prophylaxis. The high number of patients receiving on-demand treatment experiencing zero bleeds could be due to selection bias within the study, with patients with less severe disease more likely to be receiving on-demand treatment.

Trial registration

ClinicalTrials.gov: NCT02078427.

Matching-Adjusted Indirect Comparison of Recombinant Factor IX Albumin Fusion Protein Versus Recombinant Factor IX Fc Fusion Protein for Weekly Prophylactic Treatment of Hemophilia B

INTRODUCTION

Prophylactic treatment of hemophilia B with recombinant factor IX (rFIX) molecules with enhanced pharmacokinetics including rIX-FP (albutrepenonacog alfa; Idelvion©) and rFIXFc (eftrenonacog alfa; Alprolix©) have commonly been used in the clinic. In the absence of head-to-head comparative trials, the aim of this study was to estimate the efficacy of rIX-FP versus rFIXFc using matching-adjusted indirect comparisons (MAICs).

METHODS

MAIC analyses leveraged individual patient data from the PROLONG-9FP trial and published summary-level data from the B-LONG trial for subjects who received weekly prophylaxis regimens. Individual patient data were used to assign weights and balance subjects from PROLONG-9FP with subjects from B-LONG on baseline disease severity, age, prior FIX regimen, and body mass index (BMI). Six efficacy outcomes were analyzed including annualized bleeding rate (ABR), annualized spontaneous bleeding rate (AsBR), annualized joint bleeding rate (AjBR), and the proportion of subjects without bleeding events (for total, spontaneous, and joint bleeding events).

RESULTS

After adjustment for baseline disease severity, age, prior FIX regimen, and BMI, rIX-FP was associated with a statistically significant decrease in AsBR (rate ratio [RR] 0.42; 95% confidence interval [CI] 0.22, 0.82; P = 0.0107), and the proportion of patients without bleeding events (odds ratio [OR] 3.24; 95% CI 1.41, 7.45; P = 0.0057), spontaneous bleeding events (OR 3.47; 95% CI 1.56, 7.73; P = 0.0023), and joint bleeding events (OR 2.41; 95% CI 1.10, 5.26; P = 0.0274) compared with rFIXFc. Prophylactic treatment with rIX-FP was also associated with a numerically lower ABR (RR 0.75; 95% CI 0.32, 1.75; P = 0.5095) and AjBR (RR 0.82; 95% CI 0.37, 1.82; P = 0.6178).

CONCLUSION

The MAICs demonstrated that weekly prophylaxis treatment of severe hemophilia B with rIX-FP resulted in favorable efficacy outcomes as compared to rFIXFc. These findings suggest rIX-FP may offer improved clinical benefits over rFIXFc.

Adeno-associated viruses for gene therapy - clinical implications and liver-related complications, a guide for hepatologists

Gene therapy has garnered increasing interest over recent decades. Several therapies employing gene transfer mechanisms have been developed, and, of these, adeno-associated virus (AAV) vectors have demonstrated viability for use with in vivo gene therapy. Several AAV-based therapeutics have received regulatory approval in the last few years including those for retinal disease, spinal muscular atrophy or aromatic L-amino acid decarboxylase deficiency. Lately, with the introduction of novel liver-directed AAV vector-based therapeutics for the treatment of haemophilia A and B, gene therapy has attracted significant attention in the hepatology community, with the liver increasingly recognised as a target for gene therapy. However, the introduction of foreign DNA into hepatocytes is associated with a risk of hepatic reactions, with raised ALT (alanine aminotransferase) and AST (aspartate aminotransferase) being - so far - the most commonly reported side effects. The complete mechanisms underlying the ALT flairs remain to be determined and the long-term risks associated with these new treatments is not yet known. The liver community is increasingly being asked to support liver-directed gene therapy to mitigate potential liver associated harm. In this review, we focus on AAV vector-based gene therapy, shedding light on this promising technique and its remarkable success in haemophilia, with a special focus on hepatic complications and their management in daily clinical practice.