Modern haemophilia care

Inflammation, angiogenesis and sensory nerve sprouting in the synovium of bony ankylosed and not bony ankylosed knees with end-stage haemophilic arthropathy

INTRODUCTION

Clinical practice showed that patients with haemophilia (PwH) with bony ankylosed end-stage haemophilic arthropathy knees reported milder pain than those with not bony ankylosed knees.

AIM

To compare the differences in pain sensation and the histopathological differences in synovial samples of affected knee joints between PwH with bony ankylosed end-stage haemophilic arthropathy knees and those with not bony ankylosed knees.

METHODS

From January 2011 to December 2019, the synovial samples of knee joints were collected during total knee arthroplasty (TKA) surgery for end-stage haemophilic arthropathy. The visual analogue scale (VAS, 0-10) pain score was reviewed from the chart data of the patients. The thickness of the inner layer of the synovium in haematoxylin and eosin (H&E) staining sections was measured. The expression levels of Ki67, IL-1β, TNF-α, CD31, VEGF, NGF and PGP9.5 in the synovium were detected by immunohistochemistry (IHC) method.

RESULTS

Fifty-two end-stage haemophilic arthropathy knee synovial samples from 36 male PwH (34 type A and 2 type B) were collected. Fifteen knees had bony ankylosed (BA-group), and 37 were not bony ankylosed (Not-BA-group). The mean age of patients at TKA surgery of BA-group and Not-BA-group was 32 years (15) and 32 years (10), respectively (p = 0.824). Before TKA surgery, the mean VAS pain scores of patients in the Not-BA-group were significantly higher than those in the BA-group (p < 0.001). The mean thickness of the inner layer of the synovium, the mean rate of Ki67+ cells, the mean density of CD31+ vascular endothelial cells and the expression levels of IL-1β, TNF-α, VEGF and NGF in samples in the Not-BA-group was significantly higher than those in samples in the BA-group (p < 0.001, p = 0.02, p = 0.001, p = 0.117, p < 0.001, p = 0.003 and p = 0.008), respectively. The mean density of PGP9.5+ sensory neural fibres in the Not-BA-group was slightly higher than in the BA-group (p = 0.131). Linear regression analysis showed a significant positive correlation between the VAS pain score and indicators including the synovial thickness, the rate of Ki67+ cells, the expression level of IL-1β, TNF-α, VEGF, NGF and the densities of CD31+ vascular endothelial cells and PGP9.5+ nerve fibres (p < 0.05).

CONCLUSIONS

Worsened hypertrophic synovitis, angiogenesis and sensory nerve sprouting in the synovium may play a critical role in causing worse pain sensation in PwH with not bony ankylosed haemophilic arthropathy knees than in those with bony ankylosed knees.

An aberrant F8 intron 1 inversion with concomitant large duplication and deletion in a Chinese severe hemophilia A patient

OBJECTIVES

Hemophilia A (HA, OMIM: 306700) is an X-linked recessive bleeding disorder, caused by defects of the F8 gene which encodes the coagulation factor VIII (FVIII). F8 intron 22 and intron 1 inversion (Inv22 and Inv1) account for ∼45% and 1-5% of severe HA cases, respectively. We herein described an aberrant Inv1 with concomitant large duplication and deletion in a Chinese severe HA patient.

METHODS

Long distance PCR and multiplex PCR were used to detect Inv22 and Inv1. Multiplex ligation-dependent probe amplification (MLPA) was applied to examine exonic duplication and deletion of the F8 gene. Coverage analysis of read depth data from whole-genome sequencing (WGS) was used to analyze the intronic duplication and deletion of the F8 gene.

RESULTS

We have identified an aberrant F8 Inv1 in a 1-year-old Chinese severe HA patient showing inversed int1h-1 and normal int1h-2. Coverage analysis of WGS data further illustrated the aberrant Inv1 with concomitant a duplication of 117 kb and a deletion of 1.8 kb.

CONCLUSION

In conclusion, we reported an aberrant Inv1 with concomitant large duplication and deletion in a severe Chinese HA patient. Moreover, WGS provides rapid genetic diagnosis of hereditary disorders with point mutations, deletions, insertions and CNVs.

Treatment of a Hemophilia B Mouse Model with Platelet-Targeted Expression of Factor IX Padua

Targeting the coagulation factor IX (FIX) expression in platelets has been shown to be effective in ameliorating bleeding in hemophilia B (HB) mice. To improve the therapeutic effects and evaluate the safety of this gene therapy strategy, we generated a transgenic mouse model on an HB background with FIX Padua target expressed in platelets. The transgenic mice exhibited stable expression and storage of FIX Padua in platelets. The platelet-stored FIX Padua could be released with the activation of platelets, and the proportion of platelet-stored FIX Padua in whole blood was the same as that of platelet-stored wild-type human FIX. The platelet-derived FIX Padua showed substantially increased specific activity compared with wild-type FIX. Reduced bleeding volume in the FIX Padua transgenic mice demonstrated that bleeding in the mice was improved. Levels of thrombin-antithrombin complex, fibrinogen, D-Dimer, and blood cell counts were normal in the transgenic mice, suggesting that thrombotic risk was not increased in this mouse model. However, the leakage and failure to overcome the presence of inhibitor to wild-type FIX is also observed with FIX Padua, as expected. Taken together, our results support the conclusion that targeting FIX Padua expression in platelets may be an effective and safe gene therapy strategy for HB, and could provide an ideal model to evaluate the safety of platelet-targeted gene therapy for treating hemophilia.

Clinical, humanistic, and economic burden of severe hemophilia B in the United States: Results from the CHESS US and CHESS US+ population surveys

BACKGROUND

Hemophilia B is a rare congenital bleeding disorder that has a significant negative impact on patients' functionality and health-related quality of life. The standard of care for severe hemophilia B in the United States is prophylactic factor IX replacement therapy, which incurs substantial costs for this lifelong condition. Accurate estimates of the burden of hemophilia B are important for population health management and policy decisions, but have only recently accounted for current management strategies. The 'Cost of Severe Hemophilia across the US: a Socioeconomic Survey' (CHESS US) is a cross-sectional database of medical record abstractions and physician-reported information, completed by hematologists and care providers. CHESS US+ is a complementary database of completed questionnaires from patients with hemophilia. Together, CHESS US and CHESS US+ provide contemporary, comprehensive information on the burden of severe hemophilia from the provider and patient perspectives. We used the CHESS US and CHESS US+ data to analyze the clinical, humanistic, and economic burden of hemophilia B for patients treated with factor IX prophylaxis between 2017 and 2019 in the US.

RESULTS

We conducted analysis to assess clinical burden and direct medical costs from 44 patient records in CHESS US, and of direct non-medical costs, indirect costs, and humanistic burden (using the EQ-5D-5L) from 57 patients in CHESS US+. The mean annual bleed rate was 1.73 (standard deviation, 1.39); approximately 9% of patients experienced a bleed-related hospitalization during the 12-month study period. Nearly all patients (85%) reported chronic pain, and the mean EQ-5D-5L utility value was 0.76 (0.24). The mean annual direct medical cost was $614,886, driven by factor IX treatment (mean annual cost, $611,971). Subgroup analyses showed mean annual costs of $397,491 and $788,491 for standard and extended half-life factor IX treatment, respectively. The mean annual non-medical direct costs and indirect costs of hemophilia B were $2,371 and $6,931.

CONCLUSIONS

This analysis of patient records and patient-reported outcomes from CHESS US and CHESS US+ provides updated information on the considerable clinical, humanistic, and economic burden of hemophilia B in the US. Substantial unmet needs remain to improve patient care with sustainable population health strategies.

Patient Preferences to Assess Value IN Gene Therapies: Protocol Development for the PAVING Study in Hemophilia

Introduction: Gene therapies are innovative therapies that are increasingly being developed. However, health technology assessment (HTA) and payer decision making on these therapies is impeded by uncertainties, especially regarding long-term outcomes. Through measuring patient preferences regarding gene therapies, the importance of unique elements that go beyond health gain can be quantified and inform value assessments. We designed a study, namely the Patient preferences to Assess Value IN Gene therapies (PAVING) study, that can inform HTA and payers by investigating trade-offs that adult Belgian hemophilia A and B patients are willing to make when asked to choose between a standard of care and gene therapy.

Methods and Analysis: An eight-step approach was taken to establish the protocol for this study: (1) stated preference method selection, (2) initial attributes identification, (3) stakeholder (HTA and payer) needs identification, (4) patient relevant attributes and information needs identification, (5) level identification and choice task construction, (6) educational tool design, (7) survey integration, and (8) piloting and pretesting. In the end, a threshold technique survey was designed using the attributes “Annual bleeding rate,” “Chance to stop prophylaxis,” “Time that side effects have been studied,” and “Quality of Life.”

Ethics and Dissemination: The Medical Ethics Committee of UZ KU Leuven/Research approved the study. Results from the study will be presented to stakeholders and patients at conferences and in peer-reviewed journals. We hope that results from the PAVING study can inform decision makers on the acceptability of uncertainties and the value of gene therapies to patients.

Activated factor X targeted stored in platelets as an effective gene therapy strategy for both hemophilia A and B

BACKGROUND

Treatment of hemophiliacs with inhibitors remains challenging, and new treatments are in urgent need. Coagulation factor X plays a critical role in the downstream of blood coagulation cascade, which could serve as a bypassing agent for hemophilia therapy. Base on platelet-targeted gene therapy for hemophilia by our and other groups, we hypothesized that activated factor X (FXa) targeted stored in platelets might be effective in treating hemophilia A (HA) and B (HB) with or without inhibitors.

METHODS

To achieve the storage of FXa in platelets, we constructed a FXa precursor and used the integrin αIIb promoter to control the targeted expression of FXa precursor in platelets. The expression cassette (2bFXa) was carried by lentivirus and introduced into mouse hematopoietic stem and progenitor cells (HSPCs), which were then transplanted into HA and HB mice. FXa expression and storage in platelets was examined in vitro and in vivo. We evaluated the therapeutic efficacy of platelet-stored FXa by tail bleeding assays and the thrombelastography. In addition, thrombotic risk was assessed in the recipient mice and the lipopolysaccharide induced inflammation mice.

RESULTS

By transplanting 2bFXa lentivirus-transduced HSPCs into HA and HB mice, FXa was observed stably stored in platelet α-granules, the stored FXa is releasable and functional upon platelet activation. The platelet-stored FXa can significantly ameliorate bleeding phenotype in HA and HB mice as well as the mice with inhibitors. Meanwhile, no FXa leakage in plasma and no signs of increased risk of hypercoagulability were found in transplantation recipients and lipopolysaccharide induced septicemia recipients.

CONCLUSIONS

Our proof-of-principle data indicated that target expression of the FXa precursor to platelets can generate a storage pool of FXa in platelet α-granules, the platelet-stored FXa is effective in treating HA and HB with inhibitors, suggesting that this could be a novel choice for hemophilia patients with inhibitors.

Restoration of FVIII Function and Phenotypic Rescue in Hemophilia A Mice by Transplantation of MSCs Derived From F8-Modified iPSCs

Hemophilia A (HA), an X-linked recessive congenital bleeding disorder, affects 80%–85% of patients with hemophilia. Nearly half of severe cases of hemophilia are caused by a 0.6-Mb genomic inversion (Inv22) that disrupts F8. Although viral-based gene therapy has shown therapeutic effects for hemophilia B (HB), this promising approach is not applicable for HA at the present stage; this limitation is mainly due to the large size of F8 cDNA, which far exceeds the adeno-associated virus (AAV) packaging capacity. We previously reported an in situ genetic correction of Inv22 in HA patient-specific induced pluripotent stem cells (HA-iPSCs) by using TALENs. We also investigated an alternative strategy for targeted gene addition, in which cDNA of the B-domain deleted F8 (BDDF8) was targeted at the rDNA locus of HA-iPSCs using TALENickases to restore FVIII function. Mesenchymal stem cells (MSCs) have low immunogenicity and can secrete FVIII under physiological conditions; in this study, MSCs were differentiated from F8-corrected iPSCs, BDDF8-iPSCs, and HA-iPSCs. Differentiated MSCs were characterized, and FVIII expression efficacy in MSCs was verified in vitro. The three types of MSCs were introduced into HA mice via intravenous injection. Long-term engraftment with restoration of FVIII function and phenotypic rescue was observed in HA mice transplanted with F8-corrected iMSCs and BDDF8-iMSCs. Our findings suggest that ex vivo gene therapy using iMSCs derived from F8-modified iPSCs can be feasible, effective, and promising for the clinical translation of therapeutic gene editing of HA and other genetic birth defects, particularly those that involve large sequence variants.

Functional and joint evaluation in a prospective cohort of patients with severe haemophilia

INTRODUCTION

Arthropathy is the main morbidity of haemophilia. Periodic joint health assessment enables a better understanding of the limitations of these patients.

OBJECTIVE

To evaluate the functional and joint performance in patients with haemophilia at one-year follow-up, as well as its association with prophylactic treatment and attendance at scheduled consultations at a haemophilia treatment centre.

METHODS

This prospective cohort study included patients with severe haemophilia aged 7 years or more and treated at Fundação Hemocentro de Brasília, Brazil, from January 2014 to December 2018. The Hemophilia Joint Health Score and Functional Independence Score in Hemophilia were assessed at the first consultation and after a one-year follow-up.

RESULTS

The study included 69 patients. The mean age at study recruitment was 22.5 ± 4.5 years, 62.3% of patients aged 18 years or older, and 29 patients were receiving primary prophylaxis (38.0%). There was a positive correlation between HJHS and age and a negative correlation between FISH and age. The worsening HJHS was associated with non-primary prophylaxis and non-attendance at scheduled multidisciplinary consultations. The worsening FISH was associated with non-primary prophylaxis. The correlation between FISH and treatment adherence was significant for the delta.

CONCLUSION

The older the patient with haemophilia, the higher the probability of a worsening of the HJHS. In the presence of more arthropathies, the older the patient, the worse the FISH. Patients receiving primary prophylaxis show better results in the HJHS and FISH when compared to patients receiving secondary prophylaxis and/or on-demand treatment.

Long-Term Outcomes of Previously Treated Adult and Adolescent Patients with Severe Hemophilia A Receiving Prophylaxis with Extended Half-Life FVIII Treatments: An Economic Analysis from a United Kingdom Perspective

Background

The standard of care for patients with hemophilia A is prophylaxis with factor VIII (FVIII) therapies. Extended half-life (EHL) FVIII products offer a reduced infusion burden compared with standard FVIII treatments. However, comparative evidence between EHLs is lacking.

Objective

To develop a pharmacodynamic–pharmacokinetic decision model to predict comparative bleed outcomes of adolescents and adults with hemophilia A receiving treatment with various EHL FVIII therapies, capturing differences in cumulative bleeding episodes, breakthrough bleed resolution and resource costs, as well as quality-adjusted life years (QALYs).

Methods

The patient population from the pathfinder 2 Phase III clinical trial was used to understand the link between FVIII levels and annual bleeding rates (ABRs). Pharmacokinetic/pharmacodynamic modeling was subsequently applied to estimate FVIII levels for four EHL FVIII treatments (turoctocog alfa pegol [Esperoct^®], rurioctocog alfa pegol [Adynovi^®], efmoroctocog alfa [Elocta^®], and damoctocog alfa pegol [Jivi^®]) to predict comparative ABRs. FVIII consumption costs (due to prophylactic treatment and breakthrough bleed resolution) and resource costs, as well as QALYs, were subsequently estimated from a UK NHS perspective over a 70-year time horizon.

Results

Turoctocog alfa pegol prophylaxis resulted in 8–19% fewer cumulative bleeding episodes versus comparators in the base case scenario. Assuming parity in annual prophylaxis costs, turoctocog alfa pegol prophylaxis reduced the cost of product and resource use to resolve a breakthrough bleed by 9–25% versus comparators. Prophylaxis with turoctocog alfa pegol was also associated with the most QALYs, representing a discounted QALY gain of 0.35–1.05 compared with the other treatments.

Conclusion

Using a pharmacodynamic–pharmacokinetic decision model, turoctocog alfa pegol prophylaxis was associated with fewer cumulative bleeds, as well as lower product and resource costs related to resolving a breakthrough bleed and most QALYs versus comparators.

Inherited bleeding disorders in oral procedures. Assessment of prophylactic and therapeutic protocols: a scoping review

BACKGROUND

This scoping review aimed to map available evidence regarding minor/major oral procedures in patients with inherited bleeding disorders (IBDs).

METHODS

Studies in medicine or dentistry that reported minor and major oral procedures in individuals presenting IBDs (e.g. haemophilia A or B, von Willebrand disease) were selected. Search and screening were performed in PubMed/Medline, Scopus, Web of Science and Cochrane Library by two independent researchers.

RESULTS

Initial search yielded 4152 citations, of which 257 were included in the final analysis. Most of the evidence for prophylaxis use was derived from observational studies and the most-commonly reported prophylactic protocols were fresh frozen plasma and factor VIII concentrate. A considerable number of studies reported postoperative complications and hospitalizations.

CONCLUSION

The present study identified that (1) there is room for new studies to assess the use of antifibrinolytic agents with no factor replacement; (2) to date, the use of factor replacement therapy is the most indicated approach when treating patients with IBDs with adjunct systemic or local antifibrinolytic agents to reduce post-operative complications; and (3) there is a critical need for high-quality evidence studies since much of the conclusions of the included studies are not supported by statistical analysis.

Validation of the Spanish Version of the VERITAS-PRN Scale to Assess Adherence to on Demand Regimens in Patients with Hemophilia

INTRODUCTION

The episodic or on-demand administration of clotting factor concentrates in hemophilia patients in the event of hemorrhage is employed to restore hemostasis. Adherence to on-demand treatments needs to be assessed in order to improve patient management, avoiding adverse effects and serious clinical complications.

AIM

To validate the Spanish version of the treatment adherence scale in patients with hemophilia, namely, Validated Hemophilia Regimen Treatment Adherence Scale-PRN (VERITAS-PRN).

METHODS

Eighty-five patients were recruited in three hemophilia patient associations in Spain. The VERITAS-PRN scale was adapted through a back-translation process from English to Spanish. A native Spanish bilingual translator translated the scale from English to Spanish, and subsequently another native English bilingual translator translated the scale from Spanish to English. The scale was applied twice (two months apart) to assess test-retest reliability.

RESULTS

Internal consistency reliability was slightly lower in the VERITAS-PRN in Spanish (0.80) versus the English version (0.85). There were no differences (p > 0.05) between the means of the dimensions or in the total scores between the sample of patients in Spain and the USA. The test-retest reliability coefficient of the scores on the total scale was 0.80 [CI, 0.74-0.86]. The test-retest reliability coefficient was greater than 0.90 in all subscales.

CONCLUSION

The Spanish version of VERITAS-PRN has high consistency and empirical validity. This scale is useful for assessing the degree of adherence to treatment in adult patients with hemophilia following episodic infusion treatment.

Cost of hemophilia A in Turkey: an economic disease burden analysis

OBJECTIVE

Hemophilia A is the second most common bleeding disorder causing patients to have lifelong follow-up and treatment. Despite being a rare disease, hemophilia A has a high economic burden on individuals and the public. The purpose of this study was to estimate the total disease cost of hemophilia A in Turkey.

MATERIALS AND METHODS

Data used in this analysis were collected through literature review, including studies conducted in Turkey in December 2018. A disease burden analysis was performed by modeling hemophilia A-related costs among patients, their relatives, and the social security system. Two expert panels were held to evaluate real-world data sources and to provide further information. All direct medical and non-medical costs were calculated annually from the Social Security Institution of the Republic of Turkey perspective, while indirect costs were estimated from the patient and community perspective.

RESULTS

For the calendar year of 2018, the number of hemophilia A patients in Turkey were estimated to be 5,055, with an average weight of 64.7 kg. The average annual direct medical, direct non-medical, and indirect costs of hemophilia A were calculated as €93,268 ($109,286; ₺502,717), €2,533 ($2,968; ₺13,655), and €7,957 ($9,323; ₺42,888) per patient, respectively, with a total annual cost of €103,759 ($121,578; ₺559,259). For the management of patients with inhibitors (4.9%), the average annual total cost was calculated to be €325,439 ($381,330; ₺1,754,117) per patient. The total annual disease burden of hemophilia A in 2018 was estimated to be about €524 million ($614 million; ₺2.82 billion), which corresponded to 1.6% of the total health expenditure in Turkey.

CONCLUSION

The most important reason hemophilia A has a significant economic burden in Turkey is that replacement therapy is expensive. The major cost contributor was identified as factor replacement therapy. With inhibitor development, the average annual cost increased more than 3-fold.

Application of enhanced recovery after surgery in total knee arthroplasty in patients with haemophilia A: A pilot study

Aim

To identify the effect of enhanced recovery after surgery (ERAS) and rapid rehabilitation concepts on the outcomes of patients with haemophilia A undergoing total knee arthroplasty.

Design

Randomized controlled trial.

Methods

The primary endpoint was postoperative hospital stay. The secondary endpoints were pain scores, joint function scores, haemoglobin levels at 3 and 7 days after surgery and satisfaction with hospitalization.

Results

Thirty-two patients were enrolled. Compared with the routine nursing group, the ERAS group showed shorter postoperative hospital stay (14.2 SD 0.8 vs. 16.6 ± 1.3 days, p < .001), smaller amounts of blood transfusion (924 SD 317 vs. 1,263 SD 449 ml, p = .020) and coagulation factors (37,325 SD 5,996 vs. 48,475 SD 8,019 U, p < .001), lower pain scores at 3 (3.3 SD 0.7 vs. 4.3 SD 0.7, p = .002) and 7 (2.3 SD 0.7 vs. 2.8 ± 0.5, p = .015) days, lower hospital for special surgery knee scores at 3 (59.9 SD 7.8 vs. 53.6 SD 5.9, p = .016) and 7 (77.9 SD 6.9 vs. 71.1 ± 7.1, p = .009) days and higher satisfaction with hospitalization (94.3 SD 1.4 vs. 92.7 SD 1.6, p = .004).

Mechanisms of Bone Remodeling Disorder in Hemophilia

Hemophilia is caused by a lack of antihemophilic factor(s), for example, factor VIII (FVIII; hemophilia A) and factor IX (FIX; hemophilia B). Low bone mass is widely reported in epidemiological studies of hemophilia, and patients with hemophilia are at an increased risk of fracture. The detailed etiology of bone homeostasis imbalance in hemophilia is unclear. Clinical and experimental studies show that FVIII and FIX are involved in bone remodeling. However, it is likely that antihemophilic factors affect bone biology through thrombin pathways rather than via their own intrinsic properties. In addition, among patients with hemophilia, there are pathophysiological processes in several systems that might contribute to bone loss. This review summarizes studies on the association between hemophilia and bone remodeling, and might shed light on the challenges facing the care and prevention of osteoporosis and fracture in patients with hemophilia.

Patient perspectives regarding gene therapy in haemophilia: Interviews from the PAVING study

Introduction

Exploring patient perceptions regarding gene therapies may provide insights about their acceptability to patients.

Objective

To investigate opinions of people with haemophilia (PWH) regarding gene therapies. Moreover, this study aimed to identify patient‐relevant attributes (treatment features) that influence PWH’s treatment choices.

Methods

Semi‐structured individual interviews were conducted with Belgian PWH, types A and B. A predefined interview guide included information sections and open, attribute ranking and case questions. Qualitative data were organized using NVivo 12 and analysed following framework analysis. Sum totals of scores obtained in the ranking exercise were calculated per attribute.

Results

In total, 20 PWH participated in the interviews. Most participants demonstrated a positive attitude towards gene therapy and were very willing (40%; n = 8) or willing (35%; n = 7) to receive this treatment. The following five attributes were identified as most important to PWH in making their choice: annual bleeding rate, factor level, uncertainty of long‐term risks, impact on daily life, and probability that prophylaxis can be stopped. While participants were concerned about the uncertainty regarding long‐term safety, most participants were less concerned about uncertainty regarding long‐term efficacy.

Conclusions

This qualitative study showed that most PWH have a positive attitude towards gene therapy and that besides efficacy, safety and the related uncertainties, also impact on daily life is important to patients. The identified patient‐relevant attributes may be used by regulators, health technology assessment bodies and payers in their evaluation of gene therapies for haemophilia. Moreover, they may inform clinical trial design, pay‐for‐performance schemes and real‐world evidence studies.

Preclinical evaluation of a next-generation, subcutaneously administered, coagulation factor IX variant, dalcinonacog alfa

Introduction

The rapid clearance of factor IX necessitates frequent intravenous administrations to achieve effective prophylaxis for patients with hemophilia B. Subcutaneous administration has historically been limited by low bioavailability and potency. Dalcinonacog alfa was developed using a rational design approach to be a subcutaneously administered, next-generation coagulation prophylactic factor IX therapy.

Aim

This study aimed to investigate the pharmacokinetic, pharmacodynamic, and safety profile of dalcinonacog alfa administered subcutaneously in hemophilia B dogs.

Methods

Two hemophilia B dogs received single-dose daily subcutaneous dalcinonacog alfa injections for six days. Factor IX antigen and activity, whole blood clotting time, and activated partial thromboplastin time were measured at various time points. Additionally, safety assessments for clinical adverse events and evaluations of laboratory test results were conducted.

Results

There was an increase in plasma factor IX antigen with daily subcutaneous dalcinonacog alfa. Bioavailability of subcutaneous dalcinonacog alfa was 10.3% in hemophilia B dogs. Daily subcutaneous dosing of dalcinonacog alfa demonstrated the effects of bioavailability, time to maximal concentration, and half-life by reaching a steady-state activity sufficient to correct severe hemophilia to normal, after four days.

Conclusion

The increased potency of dalcinonacog alfa facilitated the initiation and completion of the Phase 1/2 subcutaneous dosing study in individuals with hemophilia B.

Emicizumab Augments Thrombus Formation in Whole Blood from Patients with Hemophilia A under High Shear Flow Conditions

BACKGROUND

 Emicizumab is a bispecific antibody to factor (F) IXa and FX that mimics the FVIIIa cofactor function. Emicizumab prophylaxis markedly decreases bleeding episodes in patients with hemophilia A (PwHAs), irrespective of the presence of FVIII inhibitors. However, thrombotic microangiopathy (TMA) was reported when repeated high doses of activated prothrombin complex concentrates (aPCC) were concomitantly used with emicizumab. Although bypassing agents (BPAs) are vital in the hemostatic treatment for PwHAs with inhibitors, the mechanism of emicizumab-related TMA remains unclear.

AIM

 To assess the risk of excessive thrombus formation associated with BPAs and emicizumab under high shear conditions.

METHODS

 Perfusion flow-chamber experiments under high shear conditions were performed using whole blood from PwHAs in the presence of emicizumab without or together with FVIII or BPAs ex vivo.

RESULTS

 Emicizumab (100 μg/mL) added ex vivo to whole blood from PwHAs improved defective thrombus formation in a similar manner to that observed with the addition of recombinant FVIII at the early phase, while FVIII continued to be important at the later stages. aPCC (1.2 U/mL equivalent to 100 U/kg) or recombinant FVIIa (1.1 µg/mL; equivalent to 90 µg/kg) together with emicizumab further promoted platelet interactions and fibrin formation ex vivo but did not induce excessive thrombus formation.

CONCLUSION

 Emicizumab enhanced thrombin generation at local sites and improved defective hemostasis in whole blood from PwHAs under high shear conditions. Simple concomitant use of BPAs with emicizumab did not mediate excessive thrombus formation and remains an option for hemostatic management of emicizumab-treated PwHAs with inhibitors.

Primary prophylaxis was associated with lower arthropathy in Colombian men with haemophilia B: A longitudinal analysis (2015-2019)

INTRODUCTION

The risk of chronic haemophilic arthropathy (CHA) is related to severity. Evidence suggests that primary prophylaxis (PPr) could reduce CHA incidence and its impact on quality of life.

AIM

To evaluate the association between PPr and CHA in Colombian males with haemophilia B (HB) during 2015 to 2019.

METHODS

A panel-time analysis was performed with data provided by the National Health System to update a nationwide open cohort of people with congenital coagulopathies. The association was evaluated in a logistic random-effect regression model (LRERM), adjusted by age at diagnosis, prophylaxis dose and frequency, severity, haemarthrosis and high-titre inhibitors.

RESULTS

During 2015-2019, a total of 362 men with HB and treated with either, primary, secondary or tertiary prophylaxis were identified. At baseline, CHA prevalence in the cohort was 36.84% (n = 133), median age was 19.0 years (IQR: 10.0-27.0), and median age at diagnosis was 1.0 year (IQR: 0.0-4.0). PPr was prescribed in 37.85% (n = 137), and median dose (IU/Kg/dose) was almost the same for primary vs. secondary/tertiary prophylaxis. Patients in PPr had a lower frequency of severe HB, CHA, haemarthrosis, infectious complications and high-titre inhibitors than those in secondary or tertiary prophylaxis (STPr). In the LRERM, PPr was associated with a significant reduction of 89.70% in the odds of CHA (aOR = 0.103, IC 95%: 0.040, 0.270; P < .001), compared with STPr.

CONCLUSIONS

PPr decreased the odds of CHA by 89.70% in males with HB in Colombia. Our findings are consistent with previous studies and support the strategy to prescribe PPr to our patients.

A mutated factor X activatable by thrombin corrects bleedings in vivo in a rabbit model of antibody-induced hemophilia A

Rendering coagulation factor X sensitive to thrombin was proposed as a strategy that can bypass the need for factor VIII. In this paper, this non-replacement strategy was evaluated in vitro and in vivo in its ability to correct factor VIII but also factor IX, X and XI deficiencies. A novel modified factor X, named Actiten, was generated and produced in the HEK293F cell line. The molecule possesses the required post-translational modifications, partially keeps its ability to be activated by RVV-X, factor VIIa/tissue factor, factor VIIIa/factor IXa and acquires the ability to be activated by thrombin. The potency of the molecule was evaluated in respective deficient plasmas or hemophilia A plasmas, for some with inhibitors. Actiten corrects dose dependently all the assayed deficient plasmas. It is able to normalize the thrombin generation at 20 μg/mL showing however an increased lagtime. It was then assayed in a rabbit antibody-induced model of hemophilia A where, in contrast to recombinant factor X wild-type, it normalized the bleeding time and the loss of hemoglobin. No sign of thrombogenicity was observed and the generation of activated factor X was controlled by the anticoagulation pathway in all performed coagulation assays. This data indicates that Actiten may be considered as a possible non replacement factor to treat hemophilia's with the advantage of being a zymogen correcting bleedings only when needed.

A Closed-Tube Nested Quantitative PCR Assay for Rapid Detection of Intron 22 Inversions in the Factor VIII Gene

BACKGROUND

An inversion of intron 22 in the Factor VIII gene (Inv22) is the causative mutation for 45% of severe hemophilia A cases. Available methods for molecular diagnosis of Inv22 are generally tedious and not ideal for routine clinical use.

METHODS

We report here a new method using a single closed-tube nested quantitative PCR (CN-qPCR) for rapid detection of Inv22. This method combines a 12-cycle long-distance PCR (LD-PCR) amplifying the int22h regions, followed by a duplex qPCR targeting two specific regions close to the int22h regions. All reagents were added to a single PCR mixture for the closed-tube assay. Sequential LD-PCR and qPCR was achieved by designing primers at substantially different melting temperatures and optimizing PCR conditions.

RESULTS

Seventy-nine male hemophilia A patients of different disease severity were tested by both the CN-qPCR assay and the standard LD-PCR assay. CN-qPCR successfully made calls for all samples, whereas LD-PCR failed in eight samples. For the 71 samples where both methods made calls, the concordance was 100%. Inv22 was detected in 17 out of the 79 samples. Additionally, CN-qPCR achieved clear separation for 10 female carriers and 10 non-Inv22 females, suggesting the assay may also be useful for molecular diagnosis of female carriers.

CONCLUSIONS

This new CN-qPCR method may provide a convenient and accurate F8 Inv22 test suitable for clinical use.

Patient Preferences in the Treatment of Hemophilia A: A Best-Worst Scaling Case 3 Analysis

OBJECTIVE

To assess patient preferences for benefits and risks in hemophilia A treatment.

METHODS

A systematic literature search and pretest interviews were conducted to determine the most patient-relevant endpoints in terms of effects, risks, and administration of hemophilia A treatments. A Best-Worst Scaling (BWS; Case 3 or multiprofile case) approach was applied in a structured questionnaire. Patients were surveyed by interviewers in a computer-assisted personal interview. Treatments in the choice scenarios comprised bleeding frequency per year, application type, risk of thromboembolic event risk, and inhibitor development. Each respondent answered 13 choice tasks, including 1 dominant task, comparing 3 treatment profiles. Data were analyzed using a mixed logit model (random-parameters logit).

RESULTS

Data from 57 patients were used. The attributes "bleeding frequency per year" and "inhibitor development" had the greatest impact on respondents' choice decisions. Patients disliked being at risk of inhibitor development more than being at risk of thromboembolic events. The type of application, whether intravenous or subcutaneous, was of less importance for patients. There was a significant preference variation for all attributes.

CONCLUSIONS

Patients value low frequency of bleeding per year and low risk of development of inhibitors the most. An increase of risk and frequency would significantly decrease the impact on choice decisions. The type of application does not seem to influence the choice decision very much compared with the other attributes. Regarding preference heterogeneity, further analysis is needed to identify subgroups among patients and their characteristics. This may help to adapt individually patient-tailored treatment alternatives for hemophilia A patients.

An overview of development in gene therapeutics in China

After setbacks related to serious adverse events 20 years ago, gene therapy is now coming back to the central stage worldwide. In the past few years, gene therapy has shown astonishing efficacy against genetic diseases and cancers. In history, China carried out the world's second gene therapy clinical trial in 1991 for hemophilia B and approved the world's first gene therapy product-Gendicine-in 2003. In recent years, numerous efforts have been made on gene editing. Here, we reviewed the past of gene therapy in China and highlighted recent advances. We also discussed the regulations and future perspectives of gene therapy in China.

Musculo-skeletal problems of the hand in haemophilia

Musculo-skeletal complications of the hand in the haemophilia patient are rare, and they include synovitis, arthropathy, pseudotumours, carpal tunnel syndrome and vascular aneurysms and pseudoaneurysms.

The best way to prevent the aforementioned musculo-skeletal complications is early continuous haematological primary prophylaxis (intravenous infusion of the deficient coagulation factor, ideally from cradle to death).

There is a wide range of procedures that a hand surgeon treating these patients should be able to manage, including synovectomy, prosthetic replacement of small joints, removal or curettage of pseudotumours, release of carpal tunnel and, occasionally, vascular reconstruction of aneurysms.

The treatment of these patients should be made at an institution with close collaboration between haematologists and hand surgeons (all surgical procedures must always be performed under cover of the deficient coagulation factor).

Cite this article: EFORT Open Rev 2020;5:328-333. DOI: 10.1302/2058-5241.5.190078

Real-world analysis of haemophilia patients in China: A single centre's experience

INTRODUCTION

The management of haemophilia is critical to minimize the risk of disability and reduce the burden on China's healthcare system.

AIM

This study was based on a single centre in China and was conducted to understand the evolution of real-world haemophilia care over the past 15 years.

METHODS

We retrospectively analysed clinical characteristics, diagnosis, treatment and medical expenditures of 428 patients with haemophilia from January 2004 to December 2018 from the Institute of Hematology & Blood Diseases Hospital in Tianjin, China.

RESULTS

The delayed diagnosis time significantly decreased from 13.3 ± 5.1 years before 2004 to 0.4 ± 0.4 year in 2014-2018 (P < .05). Among children and adults receiving prophylactic treatment, the annual factor consumption increased from 2004-2008 (168.8 IU/kg in children and 120.7 IU/kg in adults) to 2009-2013 (389.2 IU/kg in children and 316.2 IU/kg in adults) and 2014-2018 (1328.0 IU/kg in children and 878.8 IU/kg in adults, P < .001). The annual medical insurance expenditure for haemophilia had increased steadily over the past 10 years. The number of patients tested regularly for inhibitors increased from 2004 (1.9% [2/105]) to 2018 (21.5% [59/275]). The seroprevalence of hepatitis C virus (HCV) was 33.8% during the years examined, while the incidence rates of HCV among patients significantly decreased (7.3% in 2008 to 0.4% in 2018).

CONCLUSION

Significant improvements in the management of haemophilia were observed from 2004 to 2018. These results highlight the joint effort of the reimbursement policy and drug regulatory management paving the way for a better future for patients with haemophilia in China.

Physiotherapy interventions for pain management in haemophilia: A systematic review

PURPOSE

Approximately 35%-50% of people with haemophilia (PWH) report living with chronic musculoskeletal pain. Although exercise based rehabilitation is effective for pain in other arthritises, there are no published guidelines for management of chronic pain in PWH. This review aims to evaluate and appraise the current evidence of effectiveness of physiotherapy interventions on (a) pain intensity, (b) quality of life (QoL) and (c) function in PWH.

METHODS

A systematic review of five databases AMED and CINAHL, EMBASE and MEDLINE and PEDro, as well as trial registries, grey literature and hand searching key journals was completed. Included studies were critically appraised and evaluated for risk of bias. The GRADE approach was used to rate the quality of the evidence.

RESULTS

Nine trials consisting of 235 participants met the inclusion criteria. All studies had an overall risk of bias with low methodological quality. Meta-analysis was not possible due to heterogeneity across trials. Studies comparing a range of physiotherapy interventions against no intervention showed no clear beneficial effect on pain intensity or QoL. Only one study, investigating hydrotherapy or land-based exercise against control, showed positive effect for pain intensity, but rated very low on GRADE assessment. Studies comparing one physiotherapy intervention against another showed no clear benefit on pain intensity, QoL or function. LASER with exercise and hydrotherapy were shown to have some positive effects on pain intensity, but no clear benefit on function.

CONCLUSIONS

At present, there is limited evidence for the use of physiotherapy interventions in addressing the issue of pain in PWH. Better designed trials with higher quality and explicit methodology along with user involvement are needed to assess the efficacy of any proposed intervention.

Cost-Effectiveness Analysis of Recombinant Factor VIII Fc-Fusion Protein (rFVIIIFc) for the Treatment of Severe Hemophilia A in Italy Incorporating Real-World Dosing and Joint Health Data

BACKGROUND

Patients with severe hemophilia A (SHA) in Italy are routinely treated with standard half-life recombinant factor VIII (rFVIII) products. rFVIII Fc-fusion protein (rFVIIIFc) is an extended half-life rFVIII product that enables less frequent administration than rFVIII, which may support improved adherence. Available data indicate low breakthrough bleed rates and potentially improved long-term joint health for patients treated with rFVIIIFc prophylaxis.

OBJECTIVE

This study assessed the cost effectiveness of rFVIIIFc versus rFVIII from an Italian healthcare perspective.

METHODS

A Semi-Markov model was constructed to assess the lifetime costs and benefits of rFVIII and rFVIIIFc prophylaxis. rFVIII product acquisition costs from a published Italian database were included for both prophylaxis and the resolution of breakthrough bleeding. Clinical outcomes within the model were determined based on published annualized bleeding rates and literature regarding the development of target joints (TJs) as the incidence of bleeds and TJs is associated with impaired health-related quality of life. Cost effectiveness was assessed using cost per quality-adjusted life-year (QALY) gained.

RESULTS

Compared with rFVIII, rFVIIIFc was associated with a per-patient cost saving of approximately €1.3 million and QALY gains of 0.39 over a lifetime horizon. Sensitivity analyses considering alternative efficacy, dosing, and structural assumptions each showed that rFVIIIFc dominated rFVIII (i.e., provided more QALYs at a reduced cost).

CONCLUSIONS

This cost-effectiveness analysis demonstrated that rFVIIIFc may offer a cost-effective treatment option for patients with SHA in Italy.

Exploring the Impact of Infusion Frequency in Hemophilia A: Exit Interviews with Patients Participating in BAY 94-9027 Extension Studies (PROTECT VIII)

INTRODUCTION

Prophylactic treatment of severe hemophilia A is burdensome, requiring frequent intravenous injections. Extended half-life (EHL) factor VIII replacement therapies offer longer intervals between infusions while still meeting efficacy and safety outcomes; however, patient perspectives following long-term use of such products in the real-world remain unknown.

OBJECTIVE

We aimed to explore the importance of infusion frequency and the potential benefits of reduced infusion frequency among patients receiving prophylactic treatment with an EHL product (BAY 94-9027).

METHODS

Patients with severe hemophilia A participating in the PROTECT VIII extension study were invited to participate in a semi-structured, concept elicitation 'exit' interview to discuss their experiences. Participants were recruited from Israel, The Netherlands, and the US. Interview transcripts were translated into English and analyzed using thematic analysis methods.

RESULTS

Sixteen participants (29-68 years of age) infusing with BAY 94-9027 once every 7 days, once every 5 days, or twice weekly were interviewed. Participants reported infusion frequency (alongside efficacy) as the most important treatment attribute influencing their satisfaction with therapy. Patient-reported benefits of reduced infusion frequency and longer duration of factor coverage included greater ability to participate in physical activities; better vein health; less time to schedule and administer factor VIII; reduced impact on work; and improved emotional well-being.

CONCLUSIONS

This study provides rich insights into the experiences of patients with EHL products and the value of reduced infusion frequency. Such data could be of value to a range of stakeholders (e.g. regulators, payers) and facilitate patient-clinician discussions to promote tailored treatment decisions.

Hemophilia A ameliorated in mice by CRISPR-based in vivo genome editing of human Factor VIII

Hemophilia A is a monogenic disease with a blood clotting factor VIII (FVIII) deficiency caused by mutation in the factor VIII (F8) gene. Current and emerging treatments such as FVIII protein injection and gene therapies via AAV-delivered F8 transgene in an episome are costly and nonpermanent. Here, we describe a CRISPR/Cas9-based in vivo genome editing method, combined with non-homologous end joining, enabling permanent chromosomal integration of a modified human B domain deleted-F8 (BDD-F8) at the albumin (Alb) locus in liver cells. To test the approach in mice, C57BL/6 mice received tail vein injections of two vectors, AAV8-SaCas9-gRNA, targeting Alb intron 13, and AAV8-BDD-F8. This resulted in BDD-F8 insertion at the Alb locus and FVIII protein expression in the liver of vector-, but not vehicle-, treated mice. Using this approach in hemophilic mice, BDD-F8 was expressed in liver cells as functional human FVIII, leading to increased plasma levels of FVIII and restoration of blood clotting properties in a dose-dependent manor for at least 7 months, with no detectable liver toxicity or meaningful off-target effects. Based on these findings, our BDD-F8 genome editing approach may offer an efficacious, long-term and safe treatment for patients with hemophilia A.

Endovascular Management of Hemarthrosis in Patients with Bleeding Diatheses: Systematic Review

PURPOSE

In this systematic review, we report the safety and efficacy of embolization for treating hemarthrosis in patients with bleeding diatheses with or without a history of prior arthroplasty.

MATERIALS AND METHODS

A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. A structured search was performed in PubMed, Web of Science, MEDLINE, and SCOPUS databases of patients undergoing embolization for hemarthrosis. Demographic data, clinical history, angiographic findings, interventions, and outcomes were extracted and tabulated.

RESULTS

The search identified 97 unique titles of which 15 were deemed relevant comprising 78 patients with coagulopathies undergoing 93 embolization procedures. Mean follow-up time was 29 months (range 3-116.5). In the 29 patients who underwent arthroplasty prior to embolization for hemarthrosis, there were 11 bleeding recurrences (37.9%). Of these patients who experienced recurrences, 10 underwent repeat embolization as coagulation factor replacement was not sufficient to address the re-bleeding. In the 49 patients with bleeding diatheses who underwent embolization for hemarthrosis with no history of prior arthroplasty, there were 11 recurrences (22.4%) and 4 of these patients underwent repeat embolization with favorable results. There were four major procedure-related complications.

CONCLUSION

Transarterial embolization is safe and effective in addressing recurrent hemarthrosis in patients with bleeding diatheses with or without a history of arthroplasty of the affected joint.

Haemophilia A: health and economic burden of a rare disease in Portugal

BACKGROUND

Haemophilia A is a hereditary bleeding disorder, which has been considered rare and chronic. The burden of this disease in Portugal remains unknown. The aim of this study was to estimate the annualized cost and health burden of haemophilia A in Portugal.

METHODS

Data were extracted from a Portuguese expert panel, from official data and national literature. Annual costs were calculated from the perspective of the society including direct and indirect costs. Unitary costs were extracted from 2017 national official sources and are expressed in euros. Health burden was expressed in disability adjusted life years (DALYs) based on incidence and quality of life questionnaires. Estimates are presented for the overall population and stratified by severity, age group (< 18 years vs. adults) and inhibitor status.

RESULTS

The yearly average cost per patient is estimated to range from €39,654/patient without inhibitors and €302,189/patient with inhibitors, representing a 7.6 fold difference. Amongst patients without inhibitors, the annual average cost was €401 in mild, €5327 in moderate and €85,805 in severe disease. Average cost per child and adult is €72,287 and €51,737, respectively. Direct costs represent approximately 95% of all costs, of which almost the totality accounts for clotting factor replacement therapy and bypassing agents. The total annual cost of haemophilia A for the Portuguese society was estimated to be €42,66 million, one third of which was related to the treatment of patients with inhibitors. It is estimated that haemophilia A is responsible for 3878 DALYs in Portugal (497 DALYs in mild, 524 DALYs in moderate, 2031 DALYs in severe patients without inhibitors and 784 DALYs in patients with inhibitors) for the cohort of 2017 (750 patients) or 5.2 DALY/patient during lifetime.

CONCLUSIONS

Despite being rare, the economic and health burden of haemophilia A is remarkable. The main cost driver is clotting factor replacement therapy. Moreover, haemophilia A is more costly in children than in adults and rises exponentially with disease severity.

Perioperative haemostasis with full-length, PEGylated, recombinant factor VIII with extended half-life (rurioctocog alfa pegol) in patients with haemophilia A: Final results of a multicentre, single-arm phase III trial

Introduction

Rurioctocog alfa pegol (BAX 855, TAK‐660) is a PEGylated, full‐length, recombinant factor VIII (rFVIII) with extended half‐life developed from unmodified rFVIII (antihaemophilic factor [recombinant]).

Aim

To determine the perioperative haemostatic efficacy and safety of rurioctocog alfa pegol in male previously treated patients (PTPs) with severe haemophilia A.

Methods

This multicentre, single‐arm, phase III study included PTPs who were to undergo major or minor elective or minor emergency surgical, dental or other invasive procedures. Rurioctocog alfa pegol dose and frequency were individualized based on patients’ pharmacokinetic profiles for major surgeries and by rurioctocog alfa pegol incremental recovery for minor surgeries. Haemostatic efficacy was assessed using the Global Haemostatic Efficacy Assessment score.

Results

Twenty‐one patients aged 16‐61 years underwent 21 major and five minor surgeries. For all 24 evaluable surgeries, overall haemostatic efficacy was rated as excellent and blood loss comparable to that expected in non‐haemophilic patients. No blood transfusions were required intraoperatively but were administered postoperatively for four surgeries in three patients. Five injury‐related postoperative bleeding episodes occurred in five patients, of which two required additional rurioctocog alfa pegol treatment. Two non‐serious adverse events of mild severity (increased ALT level and headache) were considered possibly related to rurioctocog alfa pegol. There were no deaths or treatment‐related serious adverse events. No patients developed inhibitory antibodies to FVIII or persistent IgG‐ or IgM‐binding antibodies to FVIII, PEG‐FVIII or PEG.

Conclusion

Rurioctocog alfa pegol was well tolerated and effective for perioperative use in patients with haemophilia A and showed no signs of immunogenicity.

Fixed doses of N8-GP prophylaxis maintain moderate-to-mild factor VIII levels in the majority of patients with severe hemophilia A

BACKGROUND

N8-GP is an extended half-life recombinant factor VIII developed for prophylaxis and treatment of bleeds in patients with hemophilia A.

OBJECTIVE

To assess pharmacokinetic (PK) characteristics of N8-GP in previously treated patients with severe hemophilia A, model the time spent at hemophilia thresholds of ≥1 and ≤5 IU/dL (moderate) or >5 IU/dL (mild) FVIII levels during N8-GP prophylaxis, and investigate the relationship between N8-GP half-life and von Willebrand factor (vWF).

METHODS

PK assessments were obtained from patients with severe hemophilia A (FVIII < 1 IU/dL) participating in 4 clinical trials: pathfinder 1 (20-60 years); pathfinder 2 (12-17 and ≥18 years); pathfinder 5 (0-11 years), and pathfinder 7 (25-71 years). All PK profiles were assessed after washout and considered single-dose PK profiles. Pre- and postdose FVIII activity at steady state was measured at all visits.

RESULTS

From 69 patients, 108 PK profiles of N8-GP 50 IU/kg were assessed. Adults/adolescents received 50 IU/kg every 4 days, achieving mean trough levels of 3.0 IU/dL (95% confidence interval, 2.6-3.5, adults) and 2.7 IU/dL (1.8-4.0, adolescents). Children received 60 IU/kg twice weekly, leading to mean trough levels of 1.2 IU/dL (0.8-1.6, 0- to 5-year-olds) and 2.0 IU/dL (1.5-2.7, 6- to 11-year-olds). PK modeling predicted children dosed every 3 days and adults/adolescents dosed every 3 to 4 days would maintain FVIII levels >5 and >1 IU/dL for >80% and 100% of the time, respectively. N8-GP half-life correlated linearly with von Willebrand factor levels in adults/adolescents, less in children.

CONCLUSIONS

Prophylaxis with fixed intervals (Q4D/twice weekly) and fixed weight-based dosing (50/60 IU/kg) ensured >1 IU/dL FVIII trough levels in both adults and children.

Plant cell-made protein antigens for induction of Oral tolerance

The gut associated lymphoid tissue has effective mechanisms in place to maintain tolerance to food antigens. These can be exploited to induce antigen-specific tolerance for the prevention and treatment of autoimmune diseases and severe allergies and to prevent serious immune responses in protein replacement therapies for genetic diseases. An oral tolerance approach for the prevention of peanut allergy in infants proved highly efficacious and advances in treatment of peanut allergy have brought forth an oral immunotherapy drug that is currently awaiting FDA approval. Several other protein antigens made in plant cells are in clinical development. Plant cell-made proteins are protected in the stomach from acids and enzymes after their oral delivery because of bioencapsulation within plant cell wall, but are released to the immune system upon digestion by gut microbes. Utilization of fusion protein technologies facilitates their delivery to the immune system, oral tolerance induction at low antigen doses, resulting in efficient induction of FoxP3⁺ and latency-associated peptide (LAP)⁺ regulatory T cells that express immune suppressive cytokines such as IL-10. LAP and IL-10 expression represent potential biomarkers for plant-based oral tolerance. Efficacy studies in hemophilia dogs support clinical development of oral delivery of bioencapsulated antigens to prevent anti-drug antibody formation. Production of clinical grade materials in cGMP facilities, stability of antigens in lyophilized plant cells for several years when stored at ambient temperature, efficacy of oral delivery of human doses in large animal models and lack of toxicity augur well for clinical advancement of this novel drug delivery concept.

Universal Correction of Blood Coagulation Factor VIII in Patient-Derived Induced Pluripotent Stem Cells Using CRISPR/Cas9

Hemophilia A (HA) is caused by genetic mutations in the blood coagulation factor VIII (FVIII) gene. Genome-editing approaches can be used to target the mutated site itself in patient-derived induced pluripotent stem cells (iPSCs). However, these approaches can be hampered by difficulty in preparing thousands of editing platforms for each corresponding variant found in HA patients. Here, we report a universal approach to correct the various mutations in HA patient iPSCs by the targeted insertion of the FVIII gene into the human H11 site via CRISPR/Cas9. We derived corrected clones from two types of patient iPSCs with frequencies of up to 64% and 66%, respectively, without detectable unwanted off-target mutations. Moreover, we demonstrated that endothelial cells differentiated from the corrected iPSCs successfully secreted functional protein. This strategy may provide a universal therapeutic method for correcting all genetic variants found in HA patients.

•

Two types of FVIII mutations were corrected using Cas9-mediated KI in patient iPSCs

•

Targeted KI of the FVIII into the H11 site induced the production of functional protein

•

Whole-genome sequencing analyses revealed no off-target mutations in the corrected iPSCs

Extended Half-Life Coagulation Factors: A New Era in the Management of Hemophilia Patients

Despite effective factor replacement and various treatment schedules, there remain several challenges and unmet needs in the prophylactic treatment of hemophilia limiting its adoption and thereby posing an increased risk of spontaneous bleeding. In this regard, extended half-life (EHL) recombinant factor VIII (rFVIII) and factor IX (rFIX) products promise optimal prophylaxis by decreasing the dose frequency, increasing the compliance, and improving the quality of life without compromising safety and efficacy. EHL products might lead to higher trough levels without increasing infusion frequency, or could facilitate the ability to maintain trough levels while reducing infusion frequency. This paper aims to provide a comprehensive review of the rationale for developing EHL coagulation factors and their utility in the management of hemophilia, with special emphasis on optimal techniques for half-life extension and criteria for defining EHL coagulation factors, as well as indications, efficacy, and safety issues of the currently available EHL-rFVIII and EHL-rFIX products. Potential impacts of these factors on quality of life, health economics, and immune tolerance treatment will also be discussed alongside the challenges in pharmacokinetic-driven prophylaxis and difficulties in monitoring the EHL products with laboratory assays.

Evaluation of an automated chromogenic assay for Factor VIII clotting activity measurement in patients affected by haemophilia A

INTRODUCTION

The original one-stage clotting assay is still the most widely used method to measure Factor VIII clotting activity (FVIII:C) in patients with haemophilia A (HA), although the use of chromogenic assays is increasing significantly.

AIM

Evaluation of the analytical performance and diagnostic accuracy of BIOPHEN™ FVIII:C (HYPHEN BioMed, Neuville-sur-Oise, France) assay on Sysmex CS-2400 (Sysmex, Kobe, Japan) analyser.

METHODS

Sixty patients with haemophilia A (HA; any severity) and 120 healthy Italian subjects were included. All the assays were performed on citrate platelet-poor plasmas stored at -80°C. Chromogenic BIOPHEN™ FVIII:C was compared with the one-stage assay using Actin FS and Factor VIII deficient plasma (Siemens Healthcare Diagnostics, Marburg, Germany) on Sysmex CS-2400 and with another chromogenic automated assay (COAMATIC™ Factor VIII, CHROMOGENIX on ACL TOP analyzer; Instrumentation Laboratory, Milan, Italy).

RESULTS

Intra-assay and inter-assay coefficient of variation were <6%. Linearity was good up to 1/128 dilution (r = 0.99); mean recovery was 91.7% and limit of detection was 0.2%. BIOPHEN™ FVIII:C assay showed a good correlation and diagnostic agreement with the chromogenic COAMATIC™ assay: the Spearmen's Rank correlation coefficient was 0.98 and the inter-rate agreement K Cohen coefficient was 0.61. The K coefficient was 0.91 when BIOPHEN™ FVIII:C was compared with the historical classification of the patients, demonstrating an optimal diagnostic accuracy in HA.

CONCLUSIONS

BIOPHEN™ FVIII:C showed good analytical performance and diagnostic accuracy and could be considered suitable for the introduction in routine analytical panel of coagulation for the diagnosis of HA patients.

Current and emerging biologics for the treatment of hemophilia

INTRODUCTION

The development of new biologic agents able to restore thrombin generation has become the focus of innovation in hemophilia management. There is growing interest in the proposal of novel, non-replacement therapy with alternative mechanisms of action and route of administration, hoping to solve still unmet needs in treatment of hemophilic patients with or without inhibitors.

AREAS COVERED

The review describes the new molecules, in particular the bi-specific antibody mimicking the coagulation function of FVIII and/or those which work by inhibiting the natural anticoagulants, their mechanism of action and the results of ongoing clinical trials.

EXPERT OPINION

Exciting results in enhancing the protection against bleeding and improving quality of life are emerging from clinical trials. However, these molecules with their mechanisms of action also open new problems. Treatment of bleeding and management of surgery in subjects with a rebalanced hemostasis may be difficult, especially for the lack of laboratory tests perfectly reflecting the in vivo coagulation status. A careful surveillance is required to evaluate the risk of thrombotic complication in patients with rebalanced hemostasis, in addition to understand whether these new products offer the same protection on joints as regular prophylaxis with the missing clotting factors.

Dental management of patients with haemophilia in the era of recombinant treatments: increased efficacy and decreased clinical risk

Haemophilia is a hereditary X-linked recessive disorder caused by a deficiency of either clotting factor VIII (haemophilia A) or IX (haemophilia B). Conventional treatment is currently based on the use of either plasma derived or recombinant coagulation factors. This paper reports on the case of a patient with severe haemophilia who presented with mesial decay and interproximal tartar build-up, for which extraction and scaling to remove tartar deposits were indicated. Following extraction, the usual haemostasis techniques were applied, and postoperative prophylactic antihaemophilic treatment was indicated for 2 or 3 days. The patient presented with moderate bleeding for a few minutes immediately after the procedure. Administration of factor VIII before surgery as well as the patient’s favourable pharmacokinetic response allowed for an optimal result. This treatment has afforded patients with haemophilia a better quality of life, and safe and efficient access to invasive surgical procedures.

Population-based surveillance of haemophilia and patient outcomes in Indiana using multiple data sources

Introduction

Epidemiological surveillance of haemophilia through linkage of medical records within a US state has not been conducted in 20 years.

Aim

The Indiana Haemophilia Surveillance Project aims to identify all persons with haemophilia who resided in Indiana in 2011‐2013 and to determine the percentage of patients in Indiana cared for at a federally recognized haemophilia treatment centre (HTC).

Methods

A retrospective review of medical charts was conducted to identify haemophilia cases during the surveillance years. Case‐finding methods involved a variety of medical care resources including hospitals, administrative claims data and haematology/oncology clinic reports.

Results

In Indiana, 704 unique haemophilia cases were identified. Of those cases, 456 (64.8%) had factor VIII and 248 (35.2%) had factor IX deficiency. Among those with known severity levels (n = 685), 233 (34%) were severe, 185 (27%) were moderate, and 267 (39%) were mild. Overall, 81.7% of the haemophilia patients identified visited an HTC at least once during the three‐year study period, which was the requirement for being considered an HTC patient. Age‐adjusted prevalence for 2013 was 19.4 haemophilia cases per 100 000 males, 12.7 per 100 000 for factor VIII and 6.7 per 100 000 for factor IX. Incidence of haemophilia over the 10 years prior to the surveillance years was 1:3688 live male births in Indiana. During the surveillance years, 24 cases (3.4%) died.

Conclusion

We observed higher incidence and prevalence of haemophilia in Indiana compared to previous national estimates, as well as higher HTC utilization among persons with haemophilia.

Inhibitor development, safety and efficacy of Advate® among previously treated patients with hemophilia A in a postmarketing surveillance in Japan

Rurioctocog alfa (recombinant factor VIII: Advate^®) is available for the control of bleeding in patients with hemophilia A in Japan. To evaluate the inhibitor development, safety, and efficacy of rurioctocog alfa, a non-interventional and observational postmarketing surveillance was conducted on 352 previously treated Japanese patients aged 1-76 years with ≥ 4 exposure days under the conditions of routine clinical practice. A post-hoc comparison of the mean annualized bleeding rates which required treatment with rurioctocog alfa detected a statistically significant difference (P < 0.0001) between patients treated on regular prophylaxis (8.5 bleeds/year) and patients treated on an on-demand basis (36.6 bleeds/year). Favorable prophylactic and on-demand hemostatic efficacy ("excellent" or "good") were shown in 88.5-100% of patients across all treatment regimens. A total of 22 events of adverse drug reactions were reported in 13 male patients. Of the 352 patients, 3 (0.9%) patients, all of whom had ≤ 50 exposure days before enrollment, developed de novo FVIII inhibitor. No deaths or allergic reactions were reported. Rurioctocog alfa was found to be well-tolerated and effective among patients with hemophilia A in a postmarketing routine clinical practice.

Reaching Independence Through Forced Learning: Learning Processes and Illness Management in Parents of Children Affected by Hemophilia

Hemophilia is a complex condition to manage, especially for parents to newly diagnosed children. This grounded theory study explores parents' learning processes and illness management in daily life during the first year after the start of their child's treatment. Using a longitudinal qualitative design, eight parents of four children were interviewed repeatedly during 12 to 14 months. The core category, reaching independence through forced learning, reflected the parents' learning process and their experiences of the challenges during the first year after start of treatment. Incentives for learning were characterized by a longing to reach independence and regain control of one's life situation. The emerging key incentive for learning was a desire to become independent of health care professionals. Early home treatment reduced the impact of the illness, and by supporting parents in different ways during the learning process, health care professionals can promote the parents' trajectory toward independency.

Increased serum levels of progranulin (PGRN) in patients with haemophilic arthropathy

Haemophilia A and B are rarely occurring X chromosome-linked congenital coagulation disorders dominated by spontaneous joint bleedings and chronic synovitis, leading to development of haemophilic arthropathy (HA). Progranulin (PGRN) is a growth factor with anti-inflammatory and immunomodulatory properties. PGRN is an important molecule in the pathogenesis of osteoarthritis (OA) and rheumatological disorders. This study was aimed at investigating the potential role of PGRN in the mechanisms underlying the pathogenesis of HA. The serum levels of PGRN were measured by enzyme-linked immunosorbent assay (ELISA) in patients with end-stage knee joint HA (n = 20) and end-stage primary knee joint OA (n = 20) who met the inclusion and exclusion criteria. The clinical and radiological assessment of disease severity was evaluated by the Knee Society Score (KSS) and Kellgren-Lawrence scale. Median PGRN levels in HA patients was 349.1 ng/mL (232.8-415.6 ng/mL) and in OA patients 148.3 ng/mL (112.1-275.3 ng/mL) with statistically significant differences between both groups (P < 0.015). Further analysis revealed no correlation between PGRN levels and any of the patient demographics and clinical parameters. This study demonstrates increased PGRN serum levels in patients with HA and provides new insights into the mechanisms underlying the pathogenesis of HA indicating a new potential target for therapeutic intervention.

[Retrospectively analysis of the difference of bleeding frequency and hemophilic arthropathy between hemophilia A and hemophilia B patients]

目的

分析血友病A（HA）和血友病B（HB）的出血频率和X线分级情况、X线分级进展的危险因素及差异。

方法

回顾性分析2007年1月至2010年12月中国医学科学院血液病医院收治的211例血友病患者的临床资料，随访部分患者出血关节的X线Arnold-Hilgartner诊断分级结果。

结果

211例患者均为男性，其中HA 150例，HB 61例。HA组总体中位年均总出血次数、中位年均关节出血次数分别为20.5（0~48）、13.5（0~38）次，HB组总体中位年均总出血次数、中位年均关节出血次数分别为13（1~40）、8（0~33）次，中间型HA患者中位年均总出血次数和中位年均关节出血次数高于中间型HB患者[26（1~48）次对12（1~36）次，P<0.001；18（0~36）次对7.5（0~26）次，P=0.001]，而重型HA和HB患者中位年均总出血次数和中位年均关节出血次数比较差异无统计学意义[33（1~41）次对26（1~40）次，P=0.702；22（0~36）次对18（0~33）次，P=0.429]。108例HA、54例HB患者入院时行出血关节普通X线检查，HA患者血友病严重程度与关节X线Arnold-Hilgartner诊断分级呈正相关（r=0.063，P=0.004）；HB患者严重程度分级与关节X线Arnold-Hilgartner诊断分级无相关性（r=0.045，P=0.082）；36例HA和19例HB患者5年后复查病变关节X线片，总体HA与HB患者X线进展程度比较差异无统计学意义（z=1.941，P=0.052），但中间型HA患者进展程度高于中间型HB患者（z=0.076，P=0.002），重型HA和重型HB患者比较差异无统计学意义（z=3.139，P=0.945）。多因素分析显示关节出血次数[P<0.001，OR=1.166（95%CI 1.097~1.239）]和外伤[P=0.018，OR=2.842（95%CI 1.196~6.755）]是血友病患者关节X线Arnold-Hilgartner诊断分级进展的独立危险因素。

结论

HB患者出血频率低于HA患者，中间型患者差异尤其明显。中间型HB患者关节X线分级进展较中间型HA患者慢。关节出血次数和外伤是血友病患者关节X线Arnold-Hilgartner诊断分级进展的独立危险因素。