Modern haemophilia care

Emicizumab promotes factor Xa generation on endothelial cells

BACKGROUND

Until recently, the treatment of hemophilia A relied on factor (F)VIII replacement. However, up to one-third of patients with severe hemophilia A develop neutralizing alloantibodies that render replacement therapies ineffective. The development of emicizumab, a bispecific antibody that partially mimics FVIIIa, has revolutionized the treatment of these patients. However, the use of an activated prothrombin complex concentrate [FEIBA (Takeda)] to treat breakthrough bleeding in patients on emicizumab has been associated with thrombotic complications including a unique microangiopathy.

OBJECTIVES

We hypothesized that the thrombotic complications observed with the combination of emicizumab and FEIBA might be due to excessive expression of procoagulant activity on the surface of endothelial cells.

METHODS

We examined the ability of emicizumab to promote FX activation on endothelial cells using 2 cell culture models.

RESULTS

We found that endothelial cells readily support emicizumab-mediated activation of FX by FIXa. The level of FXa generation depends on the concentration of available FIXa. The addition of FEIBA to emicizumab increased FXa generation in a dose-dependent manner on endothelial cells in both models. The rate of FXa generation was further enhanced by endothelial cell activation. However, unlike emicizumab, we found limited FXa generation in the presence of FVIII(a), which followed a significant lag time and was not dependent on FIXa concentration under these conditions.

CONCLUSION

Emicizumab promotes FXa generation on the surface of endothelial cells, which is markedly enhanced in the presence of FEIBA. These findings demonstrate a potential mechanism for the thrombotic complications seen with the combined use of emicizumab and FEIBA.

Nonsevere Hemophilia: The Need for a Renewed Focus and Improved Outcomes

People with nonsevere hemophilia (PWNSH) are phenotypically more diverse than those with severe hemophilia. Perceptions relating to a "nonsevere" phenotype have contributed to fewer research initiatives, fewer guidelines on optimal management, and a lack of standards for surveillance and clinical assessment for affected individuals. In many cases, episodes of abnormal bleeding could, if investigated, have led to earlier diagnosis. Furthermore, the major recent developments in therapy for hemophilia have largely focused on severe disease and, as a group, PWNSH have not been included in many key clinical trials. Benefiting people with severe disease, innovative replacement therapies have generally targeted factor levels that are above those present in a large proportion of PWNSH. Therapeutic advances can lead to improvement in phenotype for people with severe hemophilia over that currently experienced by many PWNSH. As a result, we are approaching a point where PWNSH may, in many countries, have a higher risk of bleeding and restriction in lifestyle than those with severe disease but with more limited therapeutic options. Given the multiple major advances in treatment for people with hemophilia, it is timely to review the aspects of nonsevere disease, to ensure equity in care and management for all individuals with this condition.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Thrombotic Disease in Hemophilic Patients: Is This a Paradox in a State of Hypocoagulability?

Hemophilia patients have a deficiency in or dysfunction of clotting factors, which can lead to a bleeding tendency. However, paradoxically, some hemophilia patients may also be at an increased risk of developing thrombotic events such as deep vein thrombosis or pulmonary embolism. The pathophysiology of thrombosis in hemophilia patients is not fully understood, but it is thought to involve a complex interplay of various factors, including the severity of the hemophilia, the presence of other risk factors such as obesity, smoking, or the use of hormonal therapies, and the presence of certain genetic mutations that increase the risk of thrombosis. In addition, it has been suggested that the use of clotting factor replacement therapy, which is a standard treatment for hemophilia, may also contribute to the development of thrombosis in some cases.

In vivo genome editing using 244-cis LNPs and low-dose AAV achieves therapeutic threshold in hemophilia A mice

Gene therapy and rebalancing therapy have emerged as promising approaches for treating hemophilia A, but there are limitations, such as temporary efficacy due to individual differences. Genome editing for hemophilia has shown long-term therapeutic potential in preclinical trials. However, a cautious approach is necessary because genome editing is irreversible. Therefore, we attempted to induce low-level human factor 8 (hF8) gene knockin (KI) using 244-cis lipid nanoparticles and low-dose adeno-associated virus to minimize side effects and achieve a therapeutic threshold in hemophilia A mice. We selected the serpin family C member 1, SerpinC1, locus as a target to enable a combined rebalancing strategy with hF8 KI to augment efficacy. This strategy improved blood coagulation activity and reduced hemophilic complications without adverse effects. Furthermore, hemophilic mice with genome editing exhibit enhanced survival for 40 weeks. Here, we demonstrate an effective, safe, and sustainable treatment for hemophilia A. This study provides valuable information to establish safe and long-term genome-editing-mediated treatment strategies for treating hemophilia and other protein-deficient genetic diseases.

Atherosclerosis in Patients with Congenital Hemophilia: A Focus on Peripheral Artery Disease

Advances in the treatment of hemophilia have increased the life expectancy of this population and we are currently facing diseases associated with aging, including cardiovascular ones. Coronary atherosclerosis, with acute myocardial infarction as the most severe form of manifestation, has been recognized as part of the comorbidities of hemophiliacs. However, little is known about peripheral artery disease. Available data show that hemophiliacs have cardiovascular risk factors and atherosclerosis similar to the general population. Impaired thrombus formation and phenotype of atheroma plaque rather than the burden of atherosclerosis explains their lower cardiovascular mortality. Since the effect of traditional cardiovascular risk factors overpowers that of decreased coagulability and promotes the onset and progression of atherosclerotic lesions, screening for traditional cardiovascular risk factors and peripheral artery disease should be integrated into standard hemophilia care. There is evidence that invasive treatments and long-term antithrombotic therapy are generally safe, provided that coagulation factor levels are taken into account and replacement therapy is given when necessary.

The lived experience of mothers of children with haemophilia in Jordan: A phenomenological study

BACKGROUND

Haemophilia is an inherited bleeding disorder. Mothers of children with haemophilia experience stress, anxiety and different types of burdens that affect their life negatively.

OBJECTIVES

This study aimed to explore the lived experience of mothers of children with haemophilia.

METHODS

A descriptive phenomenological design was utilized. The participants were selected purposively from the Jordanian Association for Thalassemia and Hemophilia. Data saturation was achieved by interviewing 20 mothers.

RESULTS

Five themes emerged: (1) the challenges related to the diagnosis, the availability and administration of the clotting factors, and the occurrence of the bleeding emergency; (2) physical, social, psychological and financial burden; (3) fear of child death and disability; (4) stigmatization; and (5) lack of educational and medical support.

CONCLUSION

Mothers of children with haemophilia suffer from physical, psychological and social consequences. Healthcare providers should carry out educational sessions regarding the importance of support for the family and throughout the life of the child.

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.

Efficacy and safety evaluation of eptacog beta (coagulation factor VIIa [recombinant]-jncw) for the treatment of hemophilia A and B with inhibitors

INTRODUCTION

Bypassing agents (BPAs) are used to treat acute bleeding episodes, manage bleeding during perioperative care, and prophylactically minimize bleed occurrence in persons with hemophilia A or B with inhibitors (PwHABI). However, the effectiveness of BPAs that have been prescribed for the last several decades can be variable, motivating the development of a new recombinant activated factor VII, eptacog beta.

AREAS COVERED

This review covers key eptacog beta findings from phase 1b and phase 3 (PERSEPT) clinical trials, which formed the basis for its regulatory approval to treat PwHABI ages 12 and older. Descriptions of eptacog beta structure and glycosylation profile, mechanism of action, preclinical study results, and cost analyses are also presented.

EXPERT OPINION

PwHABI have had only two options for bleed treatment for the past several decades. With its distinct glycosylation profile, eptacog beta offers a novel therapy aiming to improve upon BPAs currently in use, providing an option with more than one dosing regimen and a rapid response that allows most bleeds to be treated with just one dose. This has become particularly important given the use of subcutaneous medications (e.g., emicizumab) for prophylaxis of bleeding. Clinicians should consider eptacog beta as a BPA for all PwHABI.

Model-informed pediatric dose selection of marzeptacog alfa (activated): An exposure matching strategy

Marzeptacog alfa (activated) (MarzAA) is an activated recombinant human rFVII variant intended for subcutaneous (s.c.) administration to treat or prevent bleeding in individuals with hemophilia A (HA) or B (HB) with inhibitors, and other rare bleeding disorders. The s.c. administration provides benefits over i.v. injections. The objective of the study was to support the first-in-pediatric dose selection for s.c. MarzAA to treat episodic bleeding episodes in children up through 11 years in a registrational phase III trial. Assuming the same exposure-response relationship as in adults, an exposure matching strategy was used with a population pharmacokinetics model. A sensitivity analysis evaluating the impact of doubling in absorption rate and age-dependent allometric exponents on dose selection was performed. Subsequently, the probability of trial success, defined as the number of successful trials for a given pediatric dose divided by the number of simulated trials (n = 1000) was studied. A successful trial was defined as outcome where four, three, or two out of 24 pediatric subjects per trial were allowed to fall outside the adult exposures after s.c. administration of 60 μg/kg. A dose of 60 μg/kg in children with HA/HB was supported by the clinical trial simulations to match exposures in adults. The sensitivity analyses further supported selection of the 60 μg/kg dose level in all age groups. Moreover, the probability of trial success evaluations given a plausible design confirmed the potential of a 60 μg/kg dose level. Taken together, this work demonstrates the utility of model-informed drug development and could be helpful for other pediatric development programs for rare diseases.

Total Knee Arthroplasty in Haemophilia: Long-Term Results and Survival Rate of a Modern Knee Implant with an Oxidized Zirconium Femoral Component

(1) Background: Total Knee Arthroplasty (TKA) in patient with haemophilia (PWH) has usually been performed with the use of cobalt-chrome femoral and titanium tibial components, coupled with standard polyethylene (PE) inserts. The aim of this retrospective study was to evaluate the long-term outcomes and survival rates of TKA in a series of consecutive PWH affected by severe knee arthropathy at a single institution. (2) Methods: We followed 65 patients undergoing 91 TKA, implanted using the same implant, characterized by an oxidized zirconium femoral component, coupled with a titanium tibial component, and a highly crosslinked PE. At 1, 6, and 12 months; then every year for 5 years; and finally, every other 3 years, all patients were scored for pain (VAS), function (HJHS; KSS), ROM, and radiographic changes. Kaplan-Meier survivorship curves were used to calculate the implant survival rates. (3) Results: The mean follow-up was 12.3 years (4.2-20.6). All clinical and functional scores improved significantly from preoperatively to the latest follow-up (VAS: from 6.9 to 1.3; HJHS: from 13.4 to 1.9; KSS: from 19.4 to 79; ROM: from 42.4° to 83.6°). The overall survivorship of the implants was 97.5% at the latest follow-up. (4) Conclusions: The present series showed a high survival rate of specific implants potentially linked to the choice of an oxidized zirconium coupled with a highly crosslinked PE. We promote the use of modern implants in these patients in order to ensure long-lasting positive outcomes.

Postoperative outcomes of total elbow replacement in haemophilic elbow arthropathy: A systematic review

INTRODUCTION

Total elbow replacement (TER) is a surgical treatment option for haemophilic elbow arthropathy.

AIM

To review the outcomes of TER in haemophilic elbow arthropathy. The primary outcome measures were perioperative blood loss, postoperative complications, revision rates and length of hospital stay (LOS). Secondary outcomes were elbow range of motion (ROM), functional outcome scores and the visual analogue pain scale (VAS).

MATERIALS AND METHODS

PubMed, Medline, Embase and the Cochrane register were searched conforming to the PRISMA guidelines. Only studies with a minimum postoperative follow-up of 1 year were included. Quality appraisal was performed utilizing the MINORS criteria.

RESULTS

One hundred and thirty-eight articles were identified. Following article screening, only seven studies met the inclusion criteria. A total of 51 TERs in 38 patients were performed, with the Coonrad-Morrey prosthesis utilized in 51% of cases. The pooled postoperative complication and revision rates were 49% and 29%, respectively. Surgery-related postoperative mortality was 3.9%. The mean preoperative Mayo elbow performance score (MEPS) was 43 ± 20 whereas the mean postoperative MEPS was 89 ± 6. Mean preoperative VAS was 7.2 ± 1.9 while the mean postoperative VAS was 2.0 ± 1.4. Mean preoperative and postoperative elbow flexion arcs were 54 ± 15 and 91 ± 10 degrees, respectively. Mean preoperative and postoperative forearm rotation arcs were 86 ± 40 and 135 ± 19 degrees, respectively.

CONCLUSION

TER for haemophilic elbow arthropathy provides good to excellent improvements in pain and elbow ROM postoperatively. However, the overall complication and revision rates are relatively high, when compared to TER performed for other indications.

Efficacy and safety of the B-domain-deleted TQG202 for on-demand treatment in moderate and severe haemophilia A patients: A multicentre, single-arm trial

INTRODUCTION

On-demand treatment is the most common treatment strategy for haemophilia A in China.

AIM

This study aims to evaluate the efficacy and safety of a human-derived B-domain-deleted recombinant factor VIII (TQG202) in the on-demand treatment of bleeding episodes in moderate/severe haemophilia A patients.

METHODS

This multicentre, single-arm clinical trial enrolled moderate/severe haemophilia patients previously treated with FVIII concentrates for ≥50 exposure days (EDs) from May 2017 to October 2019. TQG202 was injected intravenously on-demand for bleeding episode management. The primary endpoints were the infusion efficiency at 15 and 60 min after the first administration and haemostatic efficacy of the first bleeding episode. Safety was also monitored.

RESULTS

Fifty-six participants were enrolled with a median age of 24.5 (range: 12-64) years old. The median total dose of TQG202 was 29,250 IU per participant (range: 1750-2,02,500), and the median number of administrations was 24.5 (2-116). The median infusion efficiency at 15 and 60 min after the first administration was 155.4% and 145.2%, respectively. Among the 48 first bleeding episodes evaluated, 47 (83.9%, 95% CI: 71.7%-92.4%) had a haemostatic efficacy rating of excellent or good. Eleven (19.6%) participants had treatment-related adverse events (TRAEs), but no ≥grade 3 TRAE was observed. Inhibitor development (0.6BU) was observed in one participant (1.8%) after 22 EDs, but was undetectable after 43 EDs.

CONCLUSION

TQG202 for on-demand treatment in moderate/severe haemophilia A shows effective control of the bleeding symptoms, with a low incidence of adverse events and inhibitors development.

Central venous access devices implantation in children with severe hemophilia a: data from the children comprehensive care center of China

Objectives

To report the perioperative management experience of central venous access devices (CVAD) in Chinese children with severe hemophilia A (SHA) in China.

Methods

This retrospective study included SHA children who underwent Port-A-Cath or peripherally inserted central catheter (PICC) implantation between 2020/01 and 2021/07. Collected data included baseline characteristics, factor replacement regimen and CVAD-related complications.

Results

Nine patients had nine ports placed, and eight patients underwent 10 PICCs placement. Patients without or with low-titer inhibitor (<5 BU) received a port. The median preoperative and postoperative plasma-derived factor VIII (pd-FVIII) doses were 53.0 (44.4-61.1) and 315.9 (88.2-577.8) IU/kg. The median port duration was 189 (15-512) days, with infection incidence of 0.06 per 1000 CVAD days. Patients with high-titer inhibitors (>10 BU) received PICC. The median recombinant factor VIIa (rFVIIa) dose was 87.47 μg/kg before and for 5-7 doses after implantation over 2-3 days. The median PICC duration was 226.5 days, with infection incidence of 0.12 per 1000 catheter-days.

Conclusions

CVADs can be safely implanted in China. PICC implantation is a practical and safe option for SHA children with high-titer inhibitors.

Spontaneous retroperitoneal hematoma: a case report

BACKGROUND

Spontaneous retroperitoneal hematoma is defined as bleeding in the retroperitoneal space without any triggers such as trauma, invasive procedures, and abdominal aortic aneurysm.

CASE PRESENTATION

A 48-year-old Japanese man who experienced sudden abdominal pain, severe hypotension, and decreased hemoglobin was diagnosed with spontaneous retroperitoneal hematoma. Contrast-enhanced computed tomography revealed massive left retroperitoneal hematoma; however, neither extravasation nor causative aneurysm was noted. Through conservative management with close monitoring, he was treated and discharged on the tenth hospital day without any morbidity.

CONCLUSIONS

Spontaneous retroperitoneal hematoma treatment comprises conservative management, transcatheter arterial embolization, and surgical intervention. The mortality rate of spontaneous retroperitoneal hematoma is so high that the optimal treatment timing needs to be carefully judged on the basis of detailed evaluation, and management algorithm with clear criteria.

Teleguidance for Patient Self-Imaging of Hemophilic Joints Using Mobile Ultrasound Devices: A Pilot Study

BACKGROUND

Teleguidance on portable devices opens the possibility of joint self-imaging in persons with hemophilia (PWH).

AIMS

Determine the feasibility of patient self-imaging with/without teleguidance.

METHODS

Adult PWH received ultrasound teaching including 11 views for hemarthrosis detection in ankles, elbows, and knees. The patients acquired five randomly selected views with the Butterfly/IQ probe without assistance at 2, 6-8 weeks, and 3-4 months later, followed by teleguidance. Image acquisition was timed, patients identified anatomic landmarks, and image quality was graded. Questionnaires assessed the imaging experience. Hemophilia Joint Health Score (HJHS) indicated arthropathy status.

RESULTS

Of 132 PWH, 10 (median age 52 years) opted for study inclusion. Most had severe Hemophilia A, were white/non-Hispanic, with at least a high school degree and, overall, similar to the other 122 PWH. At 2 and 6 weeks after training, ~80% images were acquired correctly compared with 53% at 12 weeks. Accuracy of landmark recognition was ~55%. With teleguidance, all images were acquired correctly, with near-perfect image quality (P ≤ .01 compared with the 3-4 month time point). Median HJHS of scanned joints was 11.5 at each time point, demonstrating a similar spectrum of arthropathic changes. Median time of image acquisition was fast, and similar with or without teleguidance (median 01:04 [mm:ss] vs median 01:02), but differed slightly between arthropathic and non-arthropathic joints. Study participants and the imaging facilitator rated that it was easy to navigate mobile technology and acquire images with teleguidance.

CONCLUSION

Mobile ultrasound with teleguidance for joint self-imaging is feasible and warrants further exploration.

Area under the curve: Comparing the value of factor VIII replacement therapies in haemophilia A

INTRODUCTION

In factor VIII (FVIII) prophylaxis for haemophilia A, cost comparisons have used price per international unit (IU) based on the once reasonable assumption of equivalent outcome per IU. Now, with several extended half-life (EHL) products available, new outcome-oriented ways to compare products are needed. Area under the curve (AUC) quantifies FVIII levels over time after infusion providing comparable data.

AIM

To develop a decision analytical model for making indirect comparisons of FVIII replacement products based on AUC.

METHODS

A literature search identified 11 crossover studies with relevant pharmacokinetic data. A common comparator FVIII level curve was calculated using pooled data from selected studies. Absolute curves for other products were estimated based on relative differences to the common comparator (% difference vs the anchor). Three scenarios were investigated: (1) Kogenate^® versus Kovaltry^® and Jivi^® ; (2) Advate^® versus Elocta^® , NovoEight^® , Kovaltry, Adynovate^® , Afstyla^® , and ReFacto^® ; and (3) Jivi versus Elocta, Adynovate, and Kogenate. Sensitivity analyses investigated effects of assay type and dose.

RESULTS

In scenario 1, Jivi (+50%) and Kovaltry (+14%) showed larger AUCs versus Kogenate. In scenario 2, EHL products, Elocta and Adynovate, had the largest AUC (+64% and +58%, respectively) versus Advate. Compared with all other products in scenario 3, Jivi had the largest AUC by +13%-28%.

CONCLUSION

This analysis concludes that EHL products differ in relative AUC, have a larger AUC compared with standard half-life, and thus, different FVIII levels over time after infusion. This model may aid decision makers in the absence of head-to-head data.

Polypyrimidine tract binding protein knockdown reverses depression-like behaviors and cognition impairment in mice with lesioned cholinergic neurons

Background and objectives

Depression is a common comorbidity of dementia and may be a risk factor for dementia. Accumulating evidence has suggested that the cholinergic system plays a central role in dementia and depression, and the loss of cholinergic neurons is associated with memory decline in aging and Alzheimer's patients. A specific loss of cholinergic neurons in the horizontal limb of the diagonal band of Broca (HDB) is correlated with depression and dysfunction of cognition in mice. In this study, we examined the potential regenerative mechanisms of knockdown the RNA-binding protein polypyrimidine tract binding protein (PTB) in reversing depression-like behaviors and cognition impairment in mice with lesioned cholinergic neurons.

Methods

We lesioned cholinergic neurons in mice induced by injection of 192 IgG-saporin into HDB; then, we injected either antisense oligonucleotides or adeno-associated virus-shRNA (GFAP promoter) into the injured area of HDB to deplete PTB followed by a broad range of methodologies including behavioral examinations, Western blot, RT-qPCR and immunofluorescence.

Results

We found that the conversion of astrocytes to newborn neurons by using antisense oligonucleotides on PTB in vitro, and depletion of PTB using either antisense oligonucleotides or adeno-associated virus-shRNA into the injured area of HDB could specifically transform astrocytes into cholinergic neurons. Meanwhile, knockdown of PTB by both approaches could relieve the depression-like behaviors shown by sucrose preference, forced swimming or tail-suspension tests, and alleviate cognitive impairment such as fear conditioning and novel object recognition in mice with lesioned cholinergic neurons.

Conclusion

These findings suggest that supplementing cholinergic neurons after PTB knockdown may be a promising therapeutic strategy to revert depression-like behaviors and cognitive impairment.

A case report of haemophilia: a review of haemophilia and oral health implications

Haemophilia is an inherited haematological disorder that can result in prolonged bleeding in patients. Dental procedures such as extractions and periodontal surgery can be associated with post-operative bleeding; therefore, patients with the diagnosis of haemophilia must have proper medical management. In this article, we aim to illustrate the importance of: having the appropriate knowledge to manage a patient with haemophilia suspected by the dental team; the need for proper medical management; and referral of patients with symptoms of a bleeding disorder.

Characteristics of BAY 2599023 in the Current Treatment Landscape of Hemophilia A Gene Therapy

Hemophilia A, a single gene disorder leading to deficient Factor VIII (FVIII), is a suitable candidate for gene therapy. The aspiration is for single administration of a genetic therapy that would allow the production of endogenous FVIII sufficient to restore hemostasis and other biological processes. This would potentially result in reliable protection from bleeding and its associated physical and emotional impacts. Gene therapy offers the possibility of a clinically relevant improvement in disease phenotype and transformational improvement in quality of life, including an opportunity to engage in physical activities more confidently. Gene therapy products for hemophilia A in advanced clinical development use adeno-associated viral (AAV) vectors and a codon-optimized B-domain deleted FVIII transgene. However, the different AAV-based gene therapies have distinct design features, such as choice of vector capsid, enhancer and promoter regions, FVIII transgene sequence and manufacturing processes. These, in turn, impact patient eligibility, safety and efficacy. Ideally, gene therapy technology for hemophilia A should offer bleed protection, durable FVIII expression, broad eligibility and limited response variability between patients, and long-term safety. However, several limitations and challenges must be overcome. Here, we introduce the characteristics of the BAY 2599023 (AAVhu37.hFVIIIco, DTX 201) gene therapy product, including the low prevalence in the general population of anti-AAV-hu37 antibodies, as well as other gene therapy AAV products and approaches. We will examine how these can potentially meet the challenges of gene therapy, with the ultimate aim of improving the lives of patients with hemophilia A.

Insights into the Molecular Genetic of Hemophilia A and Hemophilia B: The Relevance of Genetic Testing in Routine Clinical Practice

Hemophilia A and hemophilia B are rare congenital, recessive X-linked disorders caused by lack or deficiency of clotting factor VIII (FVIII) or IX (FIX), respectively. The severity of the disease depends on the reduction of coagulation FVIII or FIX activity levels, which is determined by the type of the pathogenic variants in the genes encoding the two factors (F8 and F9, respectively). Molecular genetic analysis is widely applied in inherited bleeding disorders. The outcome of genetic analysis allows genetic counseling of affected families and helps find a link between the genotype and the phenotype. Genetic analysis in hemophilia has tremendously improved in the last decades. Many new techniques and modifications as well as analysis softwares became available, which made the genetic analysis and interpretation of the data faster and more accurate. Advances in genetic variant detection strategies facilitate identification of the causal variants in up to 97% of patients. In this review, we discuss the milestones in genetic analysis of hemophilia and highlight the importance of identification of the causative genetic variants for genetic counseling and particularly for the interpretation of the clinical presentation of hemophilia patients.

Oral tolerance to prevent anti-drug antibody formation in protein replacement therapies

Protein based therapeutics have successfully improved the quality of life for patients of monogenic disorders like hemophilia, Pompe and Fabry disease. However, a significant proportion of patients develop immune responses towards intravenously infused therapeutic protein, which can complicate or neutralize treatment and compromise patient safety. Strategies aimed at circumventing immune responses following therapeutic protein infusion can greatly improve therapeutic efficacy. In recent years, antigen-based oral tolerance induction has shown promising results in the prevention and treatment of autoimmune diseases, food allergies and can prevent anti-drug antibody formation to protein replacement therapies. Oral tolerance exploits regulatory mechanisms that are initiated in the gut associated lymphoid tissue (GALT) to promote active suppression of orally ingested antigen. In this review, we outline general perceptions and current knowledge about the mechanisms of oral tolerance, including tissue specific sites of tolerance induction and the cells involved, with emphasis on antigen presenting cells and regulatory T cells. We define several factors, such as cytokines and metabolites that impact the stability and expansion potential of these immune modulatory cells. We highlight preclinical studies that have been performed to induce oral tolerance to therapeutic proteins or enzymes for single gene disorders, such as hemophilia or Pompe disease. These studies mainly utilize a transgenic plant-based system for oral delivery of antigen in conjugation with fusion protein technology that favors the prevention of antigen degradation in the stomach while enhancing uptake in the small intestine by antigen presenting cells and regulatory T cell induction, thereby promoting antigen specific systemic tolerance.

Phase III dose selection of marzeptacog alfa (activated) informed by population pharmacokinetic modeling: A novel hemostatic drug

Marzeptacog alfa (activated) (MarzAA) is an activated recombinant human FVII (rFVIIa) variant developed as subcutaneous (s.c.) administration for the treatment or prevention of bleeding episodes in patients with hemophilia A (HA) or hemophilia B (HB) with inhibitors and other rare bleeding disorders. Population pharmacokinetic (PK) modeling was applied for dose selection for a pivotal phase III clinical trial evaluating s.c. MarzAA for episodic treatment of spontaneous or traumatic bleeding episodes. The population PK model used MarzAA intravenous and s.c. data from previously completed clinical trials in patients with HA/HB with or without inhibitors. Based on the model, clinical trial simulations were performed to predict MarzAA exposure after different dosing regimens. The exposure target was identified using an exposure-matching strategy with a wild-type rFVIIa but adjusting for the difference in potency between the two compounds. Simulations demonstrated a sufficient absorption rate and prolonged exposure following a single 60 μg/kg dose leading to 51% and 70% of the population reaching levels above the target after 3 and 6 h, respectively. According to the phase III protocol, if a second dose was required after 3 h because of a lack of efficacy, 90% of the population was observed to be above target 6 h after the initial dose. The model-informed drug development approach integrated information from several trials and guided dose selection in the pivotal phase III clinical trial for episodic treatment of an acute bleeding event in individuals with HA or HB with inhibitors without the execution of a phase II trial for that indication.

No Benefit to Platelet-rich Plasma Over Placebo Injections in Terms of Pain or Function in Patients with Hemophilic Knee Arthritis: A Randomized Trial

BACKGROUND

Hemophilic knee arthritis is one of the most common presenting symptoms of hemophilia, and its management continues to be challenging to practitioners. Preliminary research has suggested that platelet-rich plasma (PRP) may have short-term efficacy in the treatment of hemophilic knee arthritis, but evidence for this treatment is limited.

QUESTIONS/PURPOSES

What is the effectiveness of PRP compared with placebo in (1) reducing pain and improving knee joint function (as measured by WOMAC, VAS, and Hemophilia Joint Health Score [HJHS]) and (2) improving quality of life (as measured by SF-36 scores) in patients with hemophilic knee arthritis through 24 months of follow-up?

METHODS

This was a prospective, parallel-group, double-blinded, single-center, placebo-controlled randomized clinical trial that included participants from a tertiary care center starting January 1, 2019, with follow-up completed on November 30, 2021. Participants were older than 18 years and had hemophilic knee arthritis confirmed by MRI, and they were randomly allocated to interventions in a 1:1 ratio. The investigators were not informed of the randomization sequence generated by the computer. Patient groups were comparable with respect to age, gender, BMI, hemophilia type, and disease severity at baseline. Physicians delivered three sessions (one per week) of a standard intraarticular injection of PRP (n = 95) or placebo (n = 95). The rate of successful blinding was balanced across the groups, which was assessed by asking participants which injection they thought they had received. The primary outcome was the WOMAC score (range 0 to 96; higher scores indicate more pain and worse function; minimum clinically important difference, 6.4 points) over 24 months. Among the 190 patients assigned to PRP or saline injections (mean age 31 ± 7 years), 100% (190) of patients were men). There was no between-group difference in the proportion of patients who completed the trial; 97% (92 of 95) of patients in the PRP group and 94% (89 of 95) of patients in the placebo group completed the trial. The most common adverse events were injection site discomfort 8% (8 of 95) in the PRP group and 4% (4 of 95) in the placebo group. An intention-to-treat analysis was planned, but there was no crossover between groups. All patients were included in the analyses. With 95 patients in each group, the study was powered a priori at 90% to detect a difference in WOMAC score of 6.4 points, which was considered a clinically important difference.

RESULTS

There were no clinically important differences in the mean WOMAC, VAS pain, HJHS, SF-36, and MRI scores between groups at any timepoint. Intraarticular PRP did not ameliorate function, symptoms, and quality of life in patients with hemophilic knee arthritis. At 24 months of follow-up, the mean difference between the PRP and placebo groups in the WOMAC score was -1 (95% CI -5 to 2; p = 0.42). The mean difference in the VAS pain score was -0.3 (95% CI -0.8 to 0.2; p = 0.19), in the HJHS was -0.6 (95% CI -1.4 to 0.1; p = 0.10), in the SF-36 physical component summary was 0 (95% CI -2 to 3; p = 0.87), and in the SF-36 mental component summary was -1 (95% CI -3 to 2; p = 0.64). The mean differences in the MRI scores of soft tissue and osteochondral subscore were 0.1 (95% CI -0.3 to 0.5; p = 0.59) and -0.3 (95% CI -0.7 to 0.1; p = 0.19), respectively.

CONCLUSION

Among patients with hemophilic knee arthritis, three intraarticular PRP injections, compared with placebo injections, did not improve hemophilic knee symptoms, function, and quality of life over 24 months. The results of this study do not support the use of PRP injections in patients who have hemophilic knee arthritis.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Co-administration of FVIII with IVIG reduces immune response to FVIII in hemophilia A mice

Hemophilia A is an X-linked recessive congenital bleeding disorder. Exogenous infusion of FVIII is the treatment of choice, and the development of immunoglobulins against FVIII (inhibitors) remains the major challenge in clinical management of the disease. Here, we investigated the effect of co-administration of FVIII with intravenous immunoglobulin (IVIG) on the development of inhibitors in previously untreated hemophilia A mice. A group of hemophilia A mice (C57BL/6^FVIII-/-) received weekly injections of recombinant human FVIII (rFVIII) for twelve consecutive weeks while a second group received co-injections of rFVIII + IVIG. An in-house enzyme-linked immunosorbent assay (ELISA) was designed to detect antibodies to rFVIII. Every mouse in the first group developed antibodies to rFVIII. In contrast, mice treated with rFVIII + IVIG showed significantly lower antibody titers. Interestingly, when co-administration of IVIG was discontinued after 12 weeks in some mice (rFVIII continued), these mice experienced an increase in antibody titer. In contrast, mice that continued to receive rFVIII + IVIG retained significantly lower titers. In conclusion, prophylactic rFVIII co-administration with IVIG modulated the immune response to FVIII and resulted in decreased anti-FVIII antibody titer. These findings suggest that co-injection therapy with IVIG could potentially be effective in the management of hemophilia A patients at risk of inhibitor development.

Efficacy, safety and bioequivalence of the human-derived B-domain-deleted recombinant factor VIII TQG202 for prophylaxis in severe haemophilia A patients

INTRODUCTION

Current treatment of severe haemophilia A includes prophylaxis with factor VIII (FVIII) replacement. The supply of plasma-derived FVIII is short in China.

PURPOSE

To evaluate the efficacy and safety of a new B-domain deleted (BDD) recombinant FVIII (TQG202) produced by human-derived cells for prophylaxis in severe haemophilia A patients and compare the bioequivalence with Xyntha.

METHODS

This multicentre, clinical trial consisted of an open-label, randomized, two-period cross-over trial assessing single-dose pharmacokinetics (PK), and a single-arm clinical trial evaluating the efficacy and safety of 24 weeks of TQG202 prophylaxis, and repeated PK were assessed after prophylaxis phase. The single-dose was 50 IU/kg in PK assessment, and the initial dose was 30 ± 5 IU/kg for prophylaxis. The primary endpoints of prophylaxis were the annualized bleeding rate (ABR) and the incremental recovery rate of the first administration. Adverse events (AEs) were recorded.

RESULTS

Twenty-six participants were enrolled in the PK assessment and 81 participants in the prophylaxis phase. Mean age was 25.9 ± 10.8 years and all participants were male. The results of PK assessment showed TQG202 is bioequivalent to Xyntha. The total ABR was 2.0 (95% CI: 1.2-2.9) in prophylaxis phase. The mean incremental recovery rate of the first administration was .027 (95% CI: .026-.028) (IU/ml)/(IU/kg). AEs occurred in 42 participants, with an incidence of 51.9%. One severe AE not related to TQG202 occurred. No participants developed FVIII inhibitors.

CONCLUSION

TQG202 shows bioequivalence with Xyntha. The promising efficacy and tolerability in the severe haemophilia A prophylaxis support the use of TQG202in clinical practice.

Management of haemophilia A with inhibitors: A regional cross-talk

INTRODUCTION

The development of inhibitors with factor VIII (FVIII) replacement therapy is one of the most common and challenging complications of haemophilia A (HA) treatment, jeopardising treatment efficacy and predisposing patients to high risks of morbidity and mortality. The management of patients with inhibitors is particularly challenging in countries where resources are limited.

AIM

To provide a comprehensive summary of the management of HA with inhibitors while focusing on differences in practice between Western and non-Western countries and how resource scarcity can impact HA management, leading to suboptimal outcomes in patients with inhibitors.

METHODS

Summary of key evidence and regional expert opinion.

RESULTS

We address, particularly, the diagnosis of and testing for inhibitors, as well as the epidemiology of inhibitors, including incidence, prevalence and disease burden. Secondly, we provide an overview of the current treatment landscape in HA with inhibitors regarding the eradication of inhibitors with immune tolerance induction and the treatment and prevention of bleeding with bypassing agents, non-factor replacement agents and other experimental therapies. This is complemented with insights from the authors around the applicability of, and challenges associated with, such therapies in their settings of practice.

CONCLUSIONS

We conclude by proposing some key steps towards bridging the gaps in the management of HA with inhibitors in resource-limited countries, including: (1) the collection of quality data that can inform healthcare reforms and policies; (2) improving disease knowledge among healthcare practitioners and patients with the aim of standardising disease management across centres and (3) working towards promoting equal access to HA care and therapies for everyone.

Total Hip Replacement in Severe Haemophilia A: Challenges and Feasibility

The management of haemophilic patients is complicated due to multiple comorbidities. A dedicated haemophilia treatment centre with a multidisciplinary team can plan and execute elective orthopaedic surgery in such haemophilic individuals. A cementless total hip arthroplasty (THA) was performed in a 26-year-old male patient with haemophilic arthropathy of the right hip under factor VIII replacement therapy based on activated partial thromboplastin time levels. The patient received a preoperative dose of recombinant anti-haemophilic factor. Venous thromboembolic event prophylaxis was not given. Postoperative radiographs demonstrated successful prosthesis placement. The patient could bear weight and walk unassisted two weeks after surgery. THA in patients with haemophilia leads to significant improvement in joint function with a relatively low incidence of complications with modern techniques and haematological management.

The Impact of Pharmacokinetic-Guided Prophylaxis on Clinical Outcomes and Healthcare Resource Utilization in Hemophilia A Patients: Real-World Evidence from the CHESS II Study

Background

Using a pharmacokinetic (PK)-guided approach to personalize the dose and frequency of prophylactic treatment can help achieve and maintain targeted factor VIII (FVIII) trough levels in patients with hemophilia A.

Objective

Investigate clinical and healthcare resource use outcomes in patients with hemophilia A treated with or without PK-guided prophylaxis using data from the Cost of Haemophilia in Europe: A Socioeconomic Survey (CHESS) II database.

Methods

CHESS II was a cross-sectional, retrospective, burden-of-illness study incorporating data from eight European countries. Patients were eligible for this analysis if they were male, ≥18 years of age, and diagnosed with congenital hemophilia A of any severity. The clinical endpoints included annualized bleeding rate (ABR), presence and number of problem/target joints, and occurrence of joint surgeries. Healthcare resource utilization endpoints included the number of hematologist consultations and bleed-related hospitalizations or emergency department admissions. Data from November 2018 to October 2020 were included and were stratified according to treatment regimen and use of PK-guided dosing.

Results

Altogether, 281 patients on prophylaxis had available FVIII trough level data. Mean (SD) age was 35.7 (13.8) years. A specific FVIII trough level was targeted in 120 (42.7%) patients and 47 (39.2%) received PK-guided dosing. Patients receiving PK-guided dosing had a mean (SD) ABR of 2.8 (2.1) and target joint number of 0.5 (0.7), compared with 3.9 (2.7) and 0.9 (1.4), respectively, for patients receiving non-PK-guided treatment. The mean (SD) number of hematologist consultations was 7.1 (5.3) for patients receiving PK-guided dosing versus 10.7 (5.7) for those who were not. A higher proportion of patients in the non-PK-guided group required hospitalization during their lifetime compared with the PK-guided group.

Conclusion

This analysis of real-world data suggests that PK-guided dosing for prophylaxis has a beneficial impact on clinical and healthcare resource utilization outcomes in patients with hemophilia A.

Novel Gene-Correction-Based Therapeutic Modalities for Monogenic Liver Disorders

The majority of monogenic liver diseases are autosomal recessive disorders, with few being sex-related or co-dominant. Although orthotopic liver transplantation (LT) is currently the sole therapeutic option for end-stage patients, such an invasive surgical approach is severely restricted by the lack of donors and post-transplant complications, mainly associated with life-long immunosuppressive regimens. Therefore, the last decade has witnessed efforts for innovative cellular or gene-based therapeutic strategies. Gene therapy is a promising approach for treatment of many hereditary disorders, such as monogenic inborn errors. The liver is an organ characterized by unique features, making it an attractive target for in vivo and ex vivo gene transfer. The current genetic approaches for hereditary liver diseases are mediated by viral or non-viral vectors, with promising results generated by gene-editing tools, such as CRISPR-Cas9 technology. Despite massive progress in experimental gene-correction technologies, limitations in validated approaches for monogenic liver disorders have encouraged researchers to refine promising gene therapy protocols. Herein, we highlighted the most common monogenetic liver disorders, followed by proposed genetic engineering approaches, offered as promising therapeutic modalities.

Minimally invasive mitral valve repair and ablation of concomitant atrial fibrillation in a patient with severe hemophilia A

Minimally invasive mitral valve repair and ablation of atrial fibrillation, combined with FVIII level‐controlled replacement therapy, can be safely performed in patients with severe hemophilia.

Generation of an mESC model with a human hemophilia B nonsense mutation via CRISPR/Cas9 technology

BACKGROUND

Hemophilia B is a rare inherited genetic bleeding disorder caused by a deficiency or lack of coagulation factor IX, the gene for which (F9) is located on the X chromosome. Hemophilia B is currently incurable and the standard treatment is coagulation factor replacement therapy. Although gene therapy has the potential to cure hemophilia, significant barriers are still needed to be overcome, e.g., off-target effects and immunoreactivity, so new approaches must be explored. Nonsense mutations account for 8% of all the hemophilia B mutation types and can result in the development of coagulation factor inhibitors. In this study, CRISPR/Cas9 technology was used to construct a mouse embryonic stem cell model with a hemophilia B nonsense mutation (F9 c.223C > T) in humans to investigate the pathogenesis and treatment of nonsense mutations in hemophilia B.

METHODS

First, a donor plasmid with a mutation (F9 c.223 C > T) and sgRNAs were constructed. Second, both the donor plasmid and the px330-sgRNA were electroporated into mouse embryonic stem cell, and the mutant cells were then screened using puromycin and red fluorescence. Third, the mutant cell lines were tested for pluripotency and the ability to differentiate into three layers. Finally, the effect of mutation on gene function was studied in the differentiation system.

RESULTS

The mutant vector and effective sgRNA were constructed, and the mutant cell line was screened. This mutant cell line exhibited pluripotency and the ability to differentiate into three layers. This point mutation affects F9 expression at both the RNA and protein levels in the differentiation system.

CONCLUSIONS

The mutant cell line obtained in the current study had a single-base mutation rather than a base deletion or insertion in the exon, which is more similar to clinical cases. In addition, the mutant has the characteristics of mouse embryonic stem cells, and this point mutation affects F9 gene transcription and translation, which can be used as a disease model for studying the pathogenesis and treatment of hemophilia at the stem cell level.

Hidden blood loss of total knee arthroplasty in hemophilia arthritis: an analysis of influencing factors

BACKGROUND

Total knee arthroplasty is the leading way to treat hemophilia arthritis. At present, there is a lack of research on the influencing factors of blood loss in total knee arthroplasty for hemophilia arthritis. This study comprehensively explores the definite factors affecting the hidden blood loss in total knee arthroplasty for hemophilia patients.

MATERIALS AND METHODS

Ninety-two hemophilia A patients who underwent total knee arthroplasty in our center were included. Demographics, laboratory data, surgical data, and complications were collected. The Gross equation and Sehat equation were used to calculate the estimated value of hidden blood loss. Multivariate linear regression analysis was used to determine the influencing factors of hidden blood loss.

RESULT

The hidden blood loss of hemophilia A patients undergoing total knee arthroplasty was 1069.51 ± 341.99 mL, and the age was positively correlated with the hidden blood loss (P < 0.001), while tranexamic acid, FVIII prophylaxis, and incremental invivo recovery were negatively correlated with the hidden blood loss (P < 0.001, P = 0.008, P = 0.017).

CONCLUSION

Elderly patients have a greater risk of blood loss, and additional preventive measures can be appropriately added. Intraoperative intra-articular injection of tranexamic acid is recommended to reduce hidden blood loss, FVIII prophylaxis is recommended for every patient. We recommend that all HA patients measure the incremental invivo recovery and develop a personalized infusion regimen of coagulation factor.

Study on the morphological characteristics and rotational alignment axis of placement plane of the tibial component in total knee arthroplasty for hemophilia-related knee arthritis

Background

Abnormal epiphyseal growth plate development of the proximal tibia in hemophilia patients leads to notable morphological changes in the mature knee joint. This study aimed to compare the morphological characteristics of tibial component placement cut surface in patients with hemophilic arthritis (HA) and osteoarthritis (OA) and to determine the tibial component rotational alignment axis’ best position for HA patients.

Methods

Preoperative computed tomography scans of 40 OA and 40 HA patients who underwent total knee arthroplasty were evaluated using a three-dimensional (3D) software. The tibial component’s placement morphological parameters were measured. The tibial component’s rotational mismatch angles were evaluated, and the most appropriate 0°AP axis position for HA patients was investigated.

Results

In the two groups, the morphology was significantly different in some of the parameters (p < 0.05). The tibial component rotational mismatch angles were significantly different between both groups (p < 0.05). The medial 9.26° of the medial 1/3 of the patellar tendon was the point through which 0°AP axis passed for the HA patients. Similarly, the medial 13.02° of the medial 1/3 of the tibial tubercle was also the point through which the 0°AP axis passed.

Conclusions

The ratio of the anteroposterior length to the geometric transverse length of the placement section of the tibial component in HA patients was smaller than that in OA patients. The medial 9.26° of the medial 1/3 of the patellar tendon or the medial 13.02° of the medial 1/3 of the tibial tubercle seem to be an ideal reference position of the rotational alignment axis of the tibial component for HA patients.

Treatment Adherence and Health-Related Quality of Life in Patients with Hemophilia in Hong Kong

Background: This study aims to identify factors affecting health-related quality of life (HRQoL) in Chinese patients with hemophilia in Hong Kong, and to examine the association between treatment adherence and HRQoL outcomes. Methods: Patients with hemophilia A or B from a non-governmental organization reported their HRQoL and treatment adherence to prophylactic therapy using validated tools. Univariate tests and multivariable regression analysis were used to compare differences in outcomes across clinically relevant subgroups. Results: Fifty-six patients were recruited (mean age 30.4 [17.4] years; majority hemophilia A: 75%; moderate-to-severe severity: 88%). Patients who received prophylactic treatment reported fewer work/school problems (25.8 [18.9] versus 51.5 [26.3]; p = 0.001) than those who received on-demand therapy. The multivariable model showed that older age (B = 0.42, 95% CI = 0.093−0.75) and living in public housing (B = 10.24, 95% CI = 0.70−19.77) were associated with worse HRQoL. Older age was associated with treatment non-adherence (r = 0.66, p < 0.0001). Patients with poor adherence tended to report worse functioning in sports/leisure (r = 0.31, p = 0.033). Conclusions: Our results suggest that patients who were older, had lower education attainment and received on-demand treatment had poorer perception of their health. Improving adherence may lead to better HRQoL. Future work includes evaluating the occupational needs prospectively in this population.

Induction of Fetal Hemoglobin by Introducing Natural Hereditary Persistence of Fetal Hemoglobin Mutations in the γ-Globin Gene Promoters for Genome Editing Therapies for β-Thalassemia

Reactivation of γ-globin expression is a promising therapeutic approach for β-hemoglobinopathies. Here, we propose a novel Cas9/AAV6-mediated genome editing strategy for the treatment of β-thalassemia: Natural HPFH mutations -113A > G, -114C > T, -117G>A, -175T > C, -195C > G, and -198T > C were introduced by homologous recombination following disruption of BCL11A binding sites in HBG1/HBG2 promoters. Precise on-target editing and significantly increased γ-globin expression during erythroid differentiation were observed in both HUDEP-2 cells and primary HSPCs from β-thalassemia major patients. Moreover, edited HSPCs maintained the capacity for long-term hematopoietic reconstitution in B-NDG hTHPO mice. This study provides evidence of the effectiveness of introducing naturally occurring HPFH mutations as a genetic therapy for β-thalassemia.

The prevalence of anti-factor VIII and anti-factor IX antibodies among patients with hemophilia in Rabat, Morocco: a single center experience

The emergence of anti-factor VIII and anti-factor IX antibodies in hemophilia A or B is the most serious complication of hemophilia. We aim to expose through a series of patient's data, collected between 02/2009 and 02/2016 in the pediatric service of university hospital of Rabat, Morocco, the epidemiological and clinical characteristics of these patients, and to highlight the therapeutic difficulties encountered during their treatment. Out of 120 hemophiliac patients, we included 22 hemophiliac patients (18.33%, p<0.004) who developed an antibody, 21 patients with hemophilia A. Among the patients, 54.5% (n=12) exhibited moderate hemophilia, while 45.5% (n=10) had major hemophilia. The average age at diagnosis is estimated to 12±6.6 years. The circumstances of diagnosis were dominated by therapeutic inefficiency (63.64% (n=14)), then came dental extraction (9.09% (n=2)), preoperative assessment 22.73% (n=5) and hemophiliac arthropathy in a single case. The titration of antibodies in a 12-person sample ranged from 0.6 UB to 84 UB, of which (41.67% (n=5)) were low responders. The therapeutic treatment was based on fresh frozen plasma (54.55% (n=7)), recombinant activated factor VII (18.2% (n=4)), recombinant activated factor VII and PFC (18.2% (n=4)), and induction of immune tolerance. The occurrence of an inhibitory antibody represents the major residual complication of replacement therapy.

Twice Weekly Vs. Thrice Weekly Low-Dose Prophylactic Factor VIII Therapy in Children with Hemophilia A: An Open Label Randomized Trial

INTRODUCTION

Low dose factor VIII prophylactic therapy in hemophilia has not been well established till date. This randomized controlled trial compared the efficacy of twice vs. thrice weekly schedule of low dose prophylactic factor VIII in children with hemophilia A as evaluated by the bleeding rate and clinico-radiological evaluation.

METHODS

Thirty-three children with severe hemophilia A (≤18 years) were randomized into two groups. Baseline evaluation included detailed history, clinical (HJHS 2.1 score and FISH score) and radiological examination (Pettersson score and ultrasound score). Group 1 received twice weekly factor VIII prophylaxis while group 2 received thrice weekly factor VIII prophylaxis, the dose being 10 U/kg in both groups. All participants were followed up over next 6 months to one year. Data regarding acute bleeding episodes and repeat clinico-radiological assessment at the end of follow up were recorded.

RESULTS

We analyzed 14 children in twice weekly prophylaxis group and 16 children in thrice weekly prophylaxis group. Statistically insignificant difference was found between the bleeding rates in both the groups after prophylaxis with the median values of monthly bleeding rate being 0.17 and p-value of 0.79. The differences between the initial and final clinical and radiological scores within each group were found to be statistically significant. There was no significant difference in the clinical and radiological scores in between the groups.

CONCLUSION

Twice weekly FVIII therapy is effective, easily administered prophylactic schedule to prevent long-term complications of hemophilia A. Lay summaryHemophilia A is one of the most common congenital coagulation factor deficiencies. Low dose factor VIII prophylaxis is recommended for hemophilia in resource-poor settings to reduce the bleeding episodes and improve the quality of life, although the optimal schedule for the same has not been well established. A randomized controlled trial on 33 children with hemophilia A (≤18 years) was done to compare the efficacy of twice versus thrice weekly schedule of prophylactic factor VIII. Group 1 received twice weekly factor VIII prophylaxis while group 2 received thrice weekly factor VIII prophylaxis, the dose in both groups being 10 U/kg. They were evaluated by the bleeding rate and clinical (HJHS 2.1 score and FISH score) and radiological scores (Pettersson score and ultrasound score). All participants were followed up over next 6 months to one year. Data regarding acute bleeding episodes and repeat clinico-radiological assessment at end of follow up were recorded. When analyzed, statistically insignificant difference was found between the bleeding rates after the two prophylaxis regimes. There was a significant improvement between initial and final clinical and radiological scores in both the groups and no difference was recorded in between the groups. To conclude, twice weekly FVIII therapy is effective, easily administered prophylactic schedule to prevent long-term complications of hemophilia A.

Quality of life in a large multinational haemophilia B cohort (The B-Natural study) - Unmet needs remain

Introduction

The B‐Natural study is a multicentre, multinational, observational study of haemophilia B (HB) designed to increase understanding of clinical manifestations, treatment and quality of life (QoL).

Aim

To characterise and compare QoL in HB across disease severity groups and individuals with inhibitors to identify gaps in treatment.

Methods

A total of 224 individuals from 107 families were enrolled from a total of 24 centres in North America (n = 16), Europe (n = 7) and Asia (n = 1). Of these, 68 (30.4%) subjects had severe (<1 IU/dL), median age 15.6 years, 114 (50.9%) moderate (1–5 IU/dL), age 13.3 years, and 42 (18.8%) mild (>5–< 40 IU/dL), age 12.1 years, disease. Twenty‐nine participants had inhibitors or a history of inhibitors. Three versions of the EQ‐5D instrument were used as a measure of QoL: proxy (ages 4–7), youth (ages 8–15) and self (age 16+). Each instrument included a visual analogue scale ranging from 100 (best health) to 0 (worst health) to assess current day's health (EQ VAS). Range‐of‐motion (ROM) for elbows, knees and ankles was assessed using a four‐point scale, from which a composite score was calculated.

Results

In all severity groups, a proportion of subjects showed less than optimal QoL. The majority of the mild and moderate severe participants reported a normal EQ‐5D health profile (79% and 72%, respectively), whereas about half (47%) of the severe participants and only 13% of the inhibitor participants reported this profile.

Conclusion

The B‐Natural study reveals impacted QoL in all disease severities of HB including those with inhibitors. Unmet needs remain and include nonsevere HB.

Effects of replacement therapies with clotting factors in patients with hemophilia: A systematic review and meta-analysis

Background

Different prophylactic and episodic clotting factor treatments are used in the management of hemophilia. A summarize of the evidence is needed inform decision-making.

Objective

To compare the effects of factor replacement therapies in patients with hemophilia.

Methods

We performed a systematic search in PubMed, Central Cochrane Library, and Scopus. We included randomized controlled trials (RCTs) published up to December 2020, which compared different factor replacement therapies in patients with hemophilia. Random-effects meta-analyses were performed whenever possible. The certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. The study protocol was registered in PROSPERO (CRD42021225857).

Results

Nine RCTs were included in this review, of which six compared episodic with prophylactic treatment, all of them performed in patients with hemophilia A. Pooled results showed that, compared to the episodic treatment group, the annualized bleeding rate was lower in the low-dose prophylactic group (ratio of means [RM]: 0.27, 95% CI: 0.17 to 0.43), intermediate-dose prophylactic group (RM: 0.15, 95% CI: 0.07 to 0.36), and high-dose prophylactic group (RM: 0.07, 95% CI: 0.04 to 0.13). With significant difference between these subgroups (p = 0.003, I² = 82.9%). In addition, compared to the episodic treatment group, the annualized joint bleeding rate was lower in the low-dose prophylactic group (RM: 0.17, 95% CI: 0.06 to 0.43), intermediate-dose prophylactic group (RM of 0.14, 95% CI: 0.07 to 0.27), and high-dose prophylactic group (RM of 0.08, 95% CI: 0.04 to 0.16). Without significant subgroup differences. The certainty of the evidence was very low for all outcomes according to GRADE methodology. The other studies compared different types of clotting factor concentrates (CFCs), assessed pharmacokinetic prophylaxis, or compared different frequencies of medication administration.

Conclusions

Our results suggest that prophylactic treatment (at either low, intermediate, or high doses) is superior to episodic treatment for bleeding prevention. In patients with hemophilia A, the bleeding rate seems to have a dose-response effect. However, no study compared different doses of prophylactic treatment, and all results had a very low certainty of the evidence. Thus, future studies are needed to confirm these results and inform decision making.

Clinical outcome and adherence rate in Scandinavian patients with intermediate-intensity prophylaxis before and after the switch of standard half-life FVIII products to BAY 81-8973

INTRODUCTION

Treatment optimization in haemophilia A can be achieved by choice of FVIII product and knowledge of pharmacokinetics (PK), phenotype and adherence. A favourable PK profile of BAY 81-8973 (octocog alfa) (Kovaltry, Bayer AB) compared to other standard half-life (SHL) FVIII products has been suggested.

AIM

To evaluate whether the switch to BAY 81-8973, using the same dosing schedule, impact factor consumption and bleed rates, taking arthropathy and adherence into account METHODS: Forty patients on prophylaxis with SHL (median age 40.5 years) attending the haemophilia treatment centres in Malmö and Oslo were enrolled. The annualised bleeding rate (ABR) and joint bleeding rate (AJBR) before and after the switch to BAY 81-8973 was calculated. PK analyses were performed with WAPPS-Hemo. Joint health status and treatment adherence were assessed.

RESULTS

The median ABR and AJBR was 0 before and after the switch, at both centres. The median yearly factor consumption was 3,345 IU/Kg/year in the entire study group corresponding to intermediate-intensity prophylaxis in most patients and with significantly more used in Malmö (3,862 IU/Kg/year), compared to Oslo (2,337 IU/Kg/year) (P .006). There was no correlation between arthropathy and bleeding. The median BAY 81-8973 t½ was 20 h (range 7.5-29 h), with significant correlation to VWF levels, and 13.4 h after exclusion of VWF outliers. Adherence to treatment was 97%.

CONCLUSIONS

Concentrate switch, using mainly intermediate-intensity regimens with high adherence rates, preserves excellent prophylaxis outcome using standard half-life FVIII products, indicating the value of individualized prophylaxis and close follow-up.

Factor VIII prophylactic therapy reduces neurological complications in patients with Hemophilia A

BACKGROUND

Bleeding in hemophiliacs can cause complications in the central and peripheral nervous system (CNS and PNS). The incidence of intracranial hemorrhage has reduced after the introduction of prophylactic treatment with factor VIII or IX, but the benefits of this therapy have not yet been evaluated on PNS complications.

OBJECTIVE

The aim of this study was to determine the prevalence of neurological complications in hemophiliacs and verify the effect of prophylactic therapy in these patients, including PNS disorders.

METHODS

We retrospectively evaluated the prevalence of CNS and PNS disorders caused by bleeding in hemophiliacs seen at the Hemocentro Regional Norte, Ceará, Brazil, from 1992 to 2018, and we compared the incidence in different periods (before and after the introduction of prophylactic treatment in 2011).

RESULTS

Of 75 hemophilia A patients evaluated (4.61/100.000 population), 13.3% (n=10) had either CNS (n=5) or PNS (n=5) disorders secondary to bleeding. Patients submitted to factor VIII replacement prophylactic therapy were less likely to have CNS events: from 1992 to 2011, 5 of 63 patients had CNS disease, while from 2011 to 2018, there were no new cases (p=0.0181). From 2011 to 2018, 5 PNS events occurred in patients without prophylactic therapy, whereas none occurred in those covered by prophylactic therapy (5/20 versus 0/29, p=0.0081).

CONCLUSIONS

The prevalence of neurological complications in hemophiliacs in our cohort is similar to other studies. Similar to CNS, prophylactic therapy also reduces the risk of PNS complications. This is the first report in the literature showing this benefit.

Deletion of Coagulation Factor IX Compromises Bone Mass and Strength: Murine Model of Hemophilia B (Christmas Disease)

Osteopenia and osteoporosis have increasingly become a recognized morbidity in those persons with hemophilia (PwH) receiving inadequate prophylactic clotting factor replacement. Animal models can control or eliminate genetic and environmental factors and allow for invasive testing not clinically permissible. Here, we describe the skeletal phenotype of juvenile and adult male mice with a genetically engineered deficiency in coagulation factor IX (FIX KO). Although the somatic growth of FIX KO mice matched that of their wild-type (WT) littermates at 10 and 20 weeks of age, the FIX KO mice displayed reduced bone mineral density (BMD), reduced cortical and cancellous bone mass, and diminished whole bone fracture resistance. These findings coupled with parallel observations in a murine model of hemophilia A (FVIII deficiency) point to an effector downstream of the coagulation cascade that is necessary for normal skeletal development. Further study of potential mechanisms underlying the bone disease observed in rare clotting factor deficiency syndromes may lead to new diagnostic and therapeutic insights for metabolic bone diseases in general.

Efficacy, safety, and immunogenicity of rurioctocog alfa pegol for prophylactic treatment in previously treated patients with severe hemophilia A: a systematic review and meta-analysis of clinical trials

Background: Patients with severe hemophilia often present with painful joint and soft tissue bleeding which may restrict them from their daily activities. The current standard of care still relies on a regular prophylactic factor VIII (FVIII), which has a high daily treatment burden. Recently, rurioctocog alfa pegol, a third-generation recombinant FVIII with a modification in its polyethylene glycol (PEG) component, has been developed. Several trials have studied this synthetic drug as bleeding prophylaxis in severe hemophilia A. This study aims to evaluate the efficacy, safety, and immunogenicity of rurioctocog alfa pegol for previously treated patients with severe hemophilia A. Methods: This study was conducted in conformity with the PRISMA guidelines. Data were retrieved from PubMed, Scopus, Cochrane Library, Wiley Online Library, and CINAHL (via EBSCOhost). Study qualities were assessed using the Methodological Index for Non-Randomized Studies (MINORS) and Modified Jadad scales. Results: Four studies involving 517 previously treated severe hemophilia A patients were included in this study. The pooled mean of total annualized bleeding rate (ABR) and hemostatic efficacy was 2.59 (95% CI = 2.04-3.14) and 92% (95% CI = 85%-97%), respectively. Only 30 (2.3%) non-serious and one (1.4%) serious adverse events were considered related to rurioctocog alfa pegol treatment. At the end of the studies, no development of FVIII inhibitory antibodies was observed. None of the developed binding antibodies to FVIII, PEG-FVIII, or PEG was correlated to the treatment efficacy and safety. Conclusions: Despite the limited availability of direct comparison studies, our analyses indicate that rurioctocog alfa pegol could serve as a safe and effective alternative for bleeding prophylaxis in previously treated hemophilia A patients. Moreover, it appears to have low immunogenicity, which further increases the safety profile of the drug in such clinical conditions.

Advances in the management of haemophilia: emerging treatments and their mechanisms

Mainstay haemophilia treatment, namely intravenous factor replacement, poses several clinical challenges including frequent injections due to the short half-life of recombinant factors, intravenous administration (which is particularly challenging in those with difficult venous access), and the risk of inhibitor development. These impact negatively upon quality of life and treatment compliance, highlighting the need for improved therapies. Several novel pharmacological therapies developed for haemophilia aim to rebalance the clotting cascade and potentially circumvent the aforementioned challenges. These therapies utilise a range of different mechanisms, namely: the extension of the circulating half-life of standard recombinant factors; the mimicking of factor VIII cofactor activity; rebalancing of coagulation through targeting of natural anticoagulants such as antithrombin and tissue factor pathway inhibitor; and inducing the production of endogenous factors with gene therapy. These therapies carry the potential of revolutionising haemophilia treatment by alleviating the current challenges presented by mainstay factor replacement. This review will provide an overview of the key trial findings related to novel therapies based on the mechanisms described above.

Patient preferences for gene therapy in haemophilia: Results from the PAVING threshold technique survey

OBJECTIVES

The aim of the Patient preferences to Assess Value IN Gene therapies (PAVING) study was to investigate trade-offs that adult Belgian people with haemophilia (PWH) A and B are willing to make when choosing between prophylactic factor replacement therapy (PFRT) and gene therapy.

METHODS

The threshold technique was used to quantify the minimum acceptable benefit (MAB) of a switch from PFRT to gene therapy in terms of 'Annual bleeding rate' (ABR), 'Chance to stop prophylaxis' (STOP), and 'Quality of life' (QOL). The design was supported by stakeholder involvement and included an educational tool on gene therapy. Threshold intervals were analysed using interval regression models in Stata 16.

RESULTS

A total of 117 PWH completed the survey. Mean thresholds were identified for all benefits, but substantial preference heterogeneity was observed; especially for the STOP thresholds, where the distribution of preferences was bimodal. Time spent on the educational tool and residence were found to impact MAB thresholds. The most accepted (88% of PWH) gene therapy profile investigated in this study comprised of zero bleeds per year (vs. six for PFRT), 90% chance to stop prophylaxis, no impact on QoL, and 10 years of follow-up on side effects (vs. 30 for PFRT).

CONCLUSIONS

Results from this study proved the value of educating patients on novel treatments. Moreover, preference heterogeneity for novel treatments was confirmed in this study. In gene therapy decision-making, preference heterogeneity and the impact of patient education on acceptance should be considered.

Identification and Validation of Hemophilia-Related Outcomes on Japanese Electronic Medical Record Database (Hemophilia-REAL V Study)

Purpose

Routinely collected data are useful for epidemiological study in hemophilia, but few studies validated the algorithm accuracy. We aimed to develop and validate algorithms to identify patients with hemophilia A and hemophilia A-related events.

Patients and Methods

This validation study compared data from medical chart reviews to a database of routinely collected health data, including claims data and discharge abstracts, and especially electronic medical records (EMR), at a single Japanese hospital (Kurashiki Central Hospital) using a stratified sampling method. Two physicians reviewed the charts for all patients at high risk for hemophilia A, and randomly sampled patients with moderate risk. Diagnostic accuracy was determined based on sensitivity, specificity, positive predictive value (PPV), and negative predictive value.

Results

There were 1,033,845 eligible patients, of whom 31 had a diagnosis of hemophilia A. ICD-10 diagnosis code D66 in the EMR identified hemophilia A with a sensitivity of 93.5% (95% confidence interval: 78.6-99) and PPV of 61.7% (95% confidence interval: 46.4-75.5). The administration of ≥10,000 units/month of factor VIII products, as documented in the EMR, identified 81.3% of patients with prophylactic factor replacement therapy. The ICD-10 diagnosis code for intracranial bleeding in the EMR identified 75.0% of patients with intracranial bleeding, but those of gastrointestinal bleeding and major joint bleeding identified only 11.1% and 1.7%, respectively.

Conclusion

We developed and validated algorithms to identify congenital hemophilia A and hemophilia A-related events. Hemophilia A could be identified with high sensitivity and PPV, but it was still challenging to identify hemophilia A-related events.

Haemophilia

Haemophilia A and B are rare congenital, recessive X-linked disorders caused by lack or deficiency of clotting factor VIII (FVIII) or IX (FIX), respectively. The severity of the disease depends on the reduction of levels of FVIII or FIX, which are determined by the type of the causative mutation in the genes encoding the factors (F8 and F9, respectively). The hallmark clinical characteristic, especially in untreated severe forms, is bleeding (spontaneous or after trauma) into major joints such as ankles, knees and elbows, which can result in the development of arthropathy. Intracranial bleeds and bleeds into internal organs may be life-threatening. The median life expectancy was ~30 years until the 1960s, but improved understanding of the disorder and development of efficacious therapy based on prophylactic replacement of the missing factor has caused a paradigm shift, and today individuals with haemophilia can look forward to a virtually normal life expectancy and quality of life. Nevertheless, the potential development of inhibitory antibodies to infused factor is still a major hurdle to overcome in a substantial proportion of patients. Finally, gene therapy for both types of haemophilia has progressed remarkably and could soon become a reality.

First open-label, single-arm, prospective study of real-world use of FIX replacement therapy in a predominantly pediatric hemophilia B population in China

BACKGROUND

Nonacog alfa (recombinant factor IX [FIX]) is approved in China for the control and prevention of bleeding events in patients with hemophilia B. This was the first study to assess prophylaxis and on-demand therapy with recombinant FIX replacement in a real-world setting in China. This study aimed to evaluate the safety and efficacy of nonacog alfa in Chinese patients with hemophilia B.

METHODS

In this open-label, multicenter study (clinicaltrials.gov identifier NCT02336178), patients received on-demand or prophylactic treatment with intravenous nonacog alfa for approximately 6 months or 50 exposure days, whichever occurred first. The primary safety outcome was medically important events (i.e., development of FIX inhibitors, allergic reactions, and thrombotic events). Key secondary efficacy outcomes included the annualized bleeding rate for on-demand treatment and prophylaxis, response to on-demand treatment, the number of infusions per bleeding event, and the number of breakthrough bleeding events within 48 hours of prophylaxis.

RESULTS

Seventy male patients (mean [standard deviation] age 7.8 [7.2] years) were enrolled (on-demand, n = 37; prophylaxis, n = 57 [24 patients were included in both groups]). Thirty-eight (54%) patients had up to 50 FIX exposure days before the study. The only medically important event was a transient low-titer FIX inhibitor (incidence 1.4%, 95% confidence interval, 0-7.7). The mean annualized bleeding rate was 26.3 for on-demand treatment and 6.5 for prophylaxis. A mean (standard deviation) of 1.5 (1.7) nonacog alfa infusions were given per bleeding episode; 78.8% of episodes resolved with 1 infusion. Response was "excellent" or "good" for 88% of the on-demand infusions. Twenty-three bleeding events (n = 11 patients) occurred within 48 hours of 2032 prophylaxis doses (1.13%).

CONCLUSION

In the real-world setting, nonacog alfa is safe and effective for on-demand treatment and for prophylaxis for patients with hemophilia B in China.