Development of an Optimized rAAV2/6 Human Factor 8 cDNA Vector Cassette for Hemophilia a Gene Therapy

Abstract Hemophilia A, which is caused by a mutation in the Factor 8 (F8) gene resulting in a deficiency or lack of the Factor VIII (FVIII) protein, is the most common inherited bleeding disorder in humans with an estimated worldwide incidence of half a million people. The disorder is X-linked and occurs in approximately 1 in 5,000 males; however there is also a growing appreciation of the impact on carrier females having a single mutant allele, with at least 10% of hemophilia A female carriers having less than normal clotting activity. Even modest increases in Factor V III activity (>1% of normal) can have a positive impact on patient lives, thus making the disease an ideal candidate for liver-directed gene therapy. Recombinant AAV (rAAV) has been used extensively for nearly 20 years as a gene therapy vector in preclinical and clinical studies where rAAV delivery to non-dividing tissues such as liver, brain and muscle affords stable, long-term transgene expression. However, there has been a lag in the clinical translation of a rAAV gene therapy approach for Hemophilia A/human F8 (hF8) compared to Hemophilia B/human Factor 9 due to poor yields of rAAV encoding a F8 transgene at clinical scale, and a requirement for large doses of rAAV F8 vector to achieve therapeutically relevant levels of circulating human FVIII (hFVIII), with the attendant risk of inducing an AAV-directed immune response requiring transient immunosuppression. To address these issues we optimized a rAAV F8 cDNA vector cassette to improve both virus yields and liver-specific hFVIII expression. The rAAV F8 cDNA vector cassette optimization required multi-factorial modifications to the liver-specific promoter module, hF8 transgene, synthetic polyadenylation signal and vector backbone sequence. This iterative process resulted in improved vector yields at research scale and greater than five-fold improvement in vector yields at clinical scale using our proven manufacturing process. Administration of the optimized rAAV hF8 cDNA packaged in serotype AAV2/6 at a dose of ~7.2E+12 vg/kg to both wild type and Hemophilia A mice resulted in robust circulating hFVIII levels and activity (levels in wild type mice were 241.6% of normal, and activity in Hemophilia A mice were 330.9% of normal). An analysis of hF8 mRNA levels in different tissues following dosage with our optimized vector demonstrated that hF8 expression from the modified promoter module was restricted to the liver. Notably there was a striking impact on hemostasis in the Hemophilia A mice treated with the optimized rAAV hF8 cDNA, with a reduction in bleeding time from 38.3 minutes to 2.5 minutes in treated mice (n = 12, p-value < 0.0001), which is in line with bleeding times in wild type mice. Initial studies in non-human primates (NHPs) resulted in supraphysiological levels of circulating hFVIII with mean peak values of 400-600% of normal levels. A follow up dose-ranging study was performed in NHPs with a rAAV2/6 F8 cDNA vector manufactured using our GMP clinical manufacturing process. Administration of vector doses ranging from 6E+11 vg/kg to 6E+12 vg/kg resulted in therapeutic circulating levels of hFVIII that were 5% - 229% of normal levels. The peak circulating hFVIII levels achieved in this dose-ranging study using GMP clinical-scale vector exceeds the levels previously reported in NHPs by several fold on an AAV vector dose basis. The high potency of this enhanced rAAV F8 cDNA cassette could significantly reduce the dose required to achieve therapeutically relevant levels in human subjects and reduce the potential of developing immune responses to AAV capsid requiring immunosuppression. Disclosures Riley: Sangamo BioSciences Inc: Employment. Boonsripisal:Sangamo BioSciences Inc: Employment. Goodwin:Sangamo BioSciences Inc: Employment. Garces:Sangamo BioSciences Inc: Employment. Ballaron:Sangamo BioSciences Inc: Employment. Tran:Sangamo BioSciences Inc: Employment. Kang:Sangamo BioSciences Inc: Employment. Zhang:Sangamo BioSciences Inc: Employment. Meyer:Sangamo BioSciences Inc: Employment. Greengard:Sangamo BioSciences Inc: Employment. Surosky:Sangamo BioSciences Inc: Employment. Ando:Sangamo BioSciences Inc: Employment. Lillicrap:bayer: Research Funding; biogen: Research Funding; CSL: Research Funding; Octapharma: Research Funding; Sangamo Biosciences Inc: Research Funding. Nichol:Sangamo BioSciences Inc: Employment. Holmes:Sangamo BioSciences Inc: Employment.

Download Full-text

Assessing Patient Experiences with Prophylactic Treatments for Hemophilia a: Concept Elicitation for Gene Therapy

Blood ◽

10.1182/blood-2020-140307 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 33-34

Author(s):

Shawn X. Sun ◽

Oyebimpe Olayinka-Amao ◽

Dana DiBenedetti

Keyword(s):

Gene Therapy ◽

Physical Health ◽

Pharmaceutical Company ◽

Prophylactic Treatment ◽

Hemophilia A ◽

Current Therapy ◽

Specific Patient ◽

Hypothetical Scenario ◽

The Impact

Background: Gene therapy for hemophilia A is designed to be a one-time infusion to deliver functional copies of the defective factor VIII (FVIII) gene, to facilitate the endogenous production of therapeutic FVIII levels. The aim is to achieve long-term protection from bleeds without the burden of regular infusions. Aims: To better understand patients' experiences of living with hemophilia A, the impact of traditional hemophilia A treatments, and patients' perceptions of the potential value of gene therapy versus traditional prophylactic treatments. Methods: Patients were identified from the database of a US rare diseases patient organization, who also recruited and screened patients for the study using materials developed by the outcomes research organization (RTI-HS) and Takeda. Adult males aged ≥18 years with a self-reported diagnosis of moderate or severe hemophilia A, who reported using factor or nonfactor prophylactic treatment and were not currently receiving treatment for inhibitors, were eligible for the study. Eligible patients provided verbal informed consent to participate in a semi-structured, 60-minute telephone interview conducted in English by 2 members of RTI-HS who did not have access to any patient-identifying information at any time during the study. Targeted questions probed perceptions of treatment burden, impact of hemophilia A on daily life, and time spent on treatment. Additionally, questions were posed to assess patients' perceptions of the impact of traditional treatments and the potential benefits they anticipate from gene therapy. Results: Nineteen patients aged 19-55 years with moderate (n = 1) or severe (n = 18) hemophilia A were interviewed. Most (16/19, 89.5%) received prophylactic FVIII therapy, (3/19, 15.8%) were receiving nonfactor prophylactic treatment, of which 1 patient also used FVIII treatment. The aspects of current or past treatments most frequently disliked by patients were lack of efficacy, frequency of infusions, intravenous administration, vein health/scar tissue, and dosing volume. Most patients expressed satisfaction with their current treatment (18/19; 94.7%), though all listed ≥1 negative treatment impact, most frequently related to difficulties with travel (13/19; 68.4%), mood/emotions (12/19; 63.2%), day-to-day activities (10/19; 52.6%), and physical health/activities (7/19; 36.8%), including having to give up or reduce particular activities because of their treatment and needing to be more cautious, especially on nontreatment days. When presented with a hypothetical scenario for gene therapy - a one-time long-acting intravenous infusion to provide a constant level of FVIII that could reduce future bleeds - all patients stated they would choose gene therapy over their current therapy, although several said they would have initial questions regarding safety, efficacy, and duration of protection. Commonly expressed reasons for preferring gene therapy (Figure 1) included fewer infusions and less worry about the need to infuse. All 19 patients said they expected to be highly satisfied with this treatment, largely because of the long-term protection from bleeds, fewer infusions, and less concern about inhibitors. The most commonly anticipated improvements were in mood/emotions (15/19; 78.9%), specifically related to reduced concern about infusions and bleed protection. Other commonly anticipated improvements included gain in time usually spent infusing (13/19; 68.4%), easier travel (12/19; 63.2%), and improved physical health and ability to perform activities (10/19; 52.6%). Conclusions: This study identified specific patient priorities, including treatment convenience, long-lasting bleed protection, frequency of intravenous infusions, and infusion volumes. The results suggest that gene therapy clinical trials should consider evaluating patient concerns in relation to the level of patient confidence in bleed protection. A study limitation is that, at the time of the survey, data on the efficacy and safety of gene therapy were limited. In the future, the study will be expanded to include a larger population of patients with hemophilia. Disclosures Sun: Takeda Pharmaceutical Company Ltd.: Current Employment. Olayinka-Amao:Takeda Pharmaceutical Company Ltd: Other: RTI-HS was contracted by Takeda Pharmaceutical Company Ltd to conduct this work; RTI Health Solutions: Current Employment. DiBenedetti:RTI Health Solutions: Current Employment; Takeda Pharmaceutical Company Ltd: Other: RTI-HS was contracted by Takeda Pharmaceutical Company Ltd to conduct this work.

Download Full-text

Codon optimization of human factor VIII cDNAs leads to high-level expression

Blood ◽

10.1182/blood-2010-05-282707 ◽

2011 ◽

Vol 117 (3) ◽

pp. 798-807 ◽

Cited By ~ 109

Author(s):

Natalie J. Ward ◽

Suzanne M. K. Buckley ◽

Simon N. Waddington ◽

Thierry VandenDriessche ◽

Marinee K. L. Chuah ◽

...

Keyword(s):

Gene Therapy ◽

Factor Viii ◽

Viral Vectors ◽

Hemophilia A ◽

Lentiviral Vector ◽

Wild Type ◽

Fviii Activity ◽

Human Factor Viii

Abstract Gene therapy for hemophilia A would be facilitated by development of smaller expression cassettes encoding factor VIII (FVIII), which demonstrate improved biosynthesis and/or enhanced biologic properties. B domain deleted (BDD) FVIII retains full procoagulant function and is expressed at higher levels than wild-type FVIII. However, a partial BDD FVIII, leaving an N-terminal 226 amino acid stretch (N6), increases in vitro secretion of FVIII tenfold compared with BDD-FVIII. In this study, we tested various BDD constructs in the context of either wild-type or codon-optimized cDNA sequences expressed under control of the strong, ubiquitous Spleen Focus Forming Virus promoter within a self-inactivating HIV-based lentiviral vector. Transduced 293T cells in vitro demonstrated detectable FVIII activity. Hemophilic mice treated with lentiviral vectors showed expression of FVIII activity and phenotypic correction sustained over 250 days. Importantly, codon-optimized constructs achieved an unprecedented 29- to 44-fold increase in expression, yielding more than 200% normal human FVIII levels. Addition of B domain sequences to BDD-FVIII did not significantly increase in vivo expression. These significant findings demonstrate that shorter FVIII constructs that can be more easily accommodated in viral vectors can result in increased therapeutic efficacy and may deliver effective gene therapy for hemophilia A.

Download Full-text

Human-Cl Rhfviii Effectively and Safely Prevents Bleeding Episodes in Previously Treated Adult Patients with Severe Haemophilia A

Blood ◽

10.1182/blood.v120.21.1132.1132 ◽

2012 ◽

Vol 120 (21) ◽

pp. 1132-1132

Author(s):

Sigurd Knaub ◽

Toshko Lissitchkov ◽

Kingsley Hampton ◽

Mario Von Depka ◽

Savita Rangarajan ◽

...

Keyword(s):

Gene Therapy ◽

Research Funding ◽

Prophylactic Treatment ◽

Hemophilia A ◽

Haemophilia A ◽

Severe Haemophilia ◽

Open Label ◽

Bleeding Rate ◽

Previously Treated

Abstract Abstract 1132 The main purpose of this prospective, multi-center, open-label phase 3 study was to assess the efficacy of prophylactic treatment with Human-cl rhFVIII, the first human cell-line derived recombinant FVIII, in previously treated patients (PTPs) with severe haemophilia A. Patients were to receive 30–40 international units (IU) FVIII of Human-cl rhFVIII per kg every other day for 6 months. Efficacy of preventing and treating bleeds were judged using objective criteria taking the monthly bleeding rate and the number of infusions needed to manage a break-through bleed into account. In-vivo recovery (IVR) was determined at the beginning of the study and after 3 and 6 months. FVIII:C was measured by validated chromogenic (CHR) and one-stage (OS) assays in a central laboratory, which also assigned drug potencies. Inhibitor activity was determined using the Nijmegen modification of the Bethesda assay before the first administration and at defined intervals thereafter. Thirty-two patients between 18 and 75 years of age were enrolled from 11 centres in Europe and treated prophylactically for 6.0±0.9 months (mean ± SD) with a mean prophylactic dose of 32.8 IU/kg. Sixteen patients never bled, 11 patients bled once and 5 more than once. The mean total and spontaneous monthly bleeding rate was 0.188±0.307 and 0.095±0.211, respectively. Efficacy of the prophylactic treatment was “excellent” in all patients for spontaneous BEs and “excellent” or “good” in all patients but one for all types of bleeds. All treatments of bleeds were rated as “excellent” (71.4%) or “good” (28.6%). The IVR at baseline was 2.6±0.5 % per IU/kg for the CHR and 2.2±0.5 % per IU/kg for the OS assay and remained stable during the study. A total of 2921 infusions were given in the study. Human-cl rhFVIII was well tolerated and no patient experienced a related serious adverse event. No FVIII inhibitors were detected. Conclusion: The data indicate that Human-cl rh FVIII is safe and efficacious in preventing and treating bleeds in PTPs with severe haemophlia A. Disclosures: Knaub: Octapharma AG: Employment. Lissitchkov:Octapharma AG: PI Other. Tuddenham:College London: Consultancy, Employment, Gene therapy for hemophilia A, Gene therapy for hemophilia A Patents & Royalties, Research Funding. Collins:Octapharma AG: Consultancy. Oldenburg:d and e: Baxter, Bayer, Biotest, CSL-Behring, Grifols, Inspiration, NovoNordisk, Octapharma, Pfizer e: Biogen IDec, Swedish Orphan Biovitrum: Honoraria, Research Funding. Bichler:Octapharma AG: Employment.

Download Full-text

Hemophilia a Clots Generated with Recombinant Factor VIIa Differed in Structure and Composition from Those Formed with Factor VIII

Blood ◽

10.1182/blood.v128.22.3798.3798 ◽

2016 ◽

Vol 128 (22) ◽

pp. 3798-3798

Author(s):

Lilley Leong ◽

Irina N. Chernysh ◽

Yifan Xu ◽

Cornell Mallari ◽

Billy Wong ◽

...

Keyword(s):

Factor Viii ◽

Whole Blood ◽

Neutralizing Antibodies ◽

Research Funding ◽

Thrombin Generation ◽

Hemophilia A ◽

Clot Formation ◽

Factor Vii ◽

Wild Type ◽

Independent Mechanism

Abstract Patients with severe factor VIII (FVIII) deficiency (hemophilia A [HemA]) develop neutralizing antibodies (inhibitors) against FVIII in up to ~30% of cases. For HemA patients with inhibitors, activated recombinant factor VII (rFVIIa) is a treatment option. High levels of rFVIIa are required for treating HemA patients with inhibitors to induce direct activation of factor X on the surface of activated platelets via a tissue factor (TF)-independent mechanism (Hoffman M, Monroe DM. Thromb Res. 2010;125(suppl 1):S16-S18). To assess how rFVIIa-mediated clot formation in HemA patients with inhibitors may differ from unaffected individuals, we compared the effect of rFVIIa on HemA versus control (or HemA supplemented with 100% FVIII) clot formation in human and/or mouse systems. By TF-induced thrombin generation assay, increasing rFVIIa from 5 nM to 100 nM did not appreciably alter the kinetics or extent of thrombin generation compared with the same human HemA plasma containing 100% FVIII. Confocal microscopy of human HemA plasma clots generated with 75 nM rFVIIa and TF showed few branching fibrin fibers and an open fibrin meshwork. In contrast, TF-induced coagulation of the same HemA plasma containing 100% FVIII formed fibrin clots with numerous branches, interconnecting to form a dense meshwork. To confirm that these findings reflect rFVIIa-mediated clot formation in vivo, we assessed the intrinsic coagulation of mouse HemA whole blood collected without anticoagulant and spiked with rFVIIa. Intrinsic coagulation with rFVIIa was assessed by T2 magnetic resonance (T2MR), a technique capable of monitoring the separation of whole blood into serum, loose-clot, and tight-clot compartments during coagulation (Skewis et al. Clin Chem. 2014;60:1174-1182; Cines et al. Blood. 2014;123:1596-1603). By T2MR, rFVIIa induced the separation of HemA whole blood into the serum and clot compartments, indicating that the reduced fibrin generation with rFVIIa did not interfere with whole blood coagulation. Furthermore, saphenous vein puncture of HemA mice treated with rFVIIa showed a dose-dependent decrease in clot times. Scanning electron microscopy of the clots extracted from these HemA mice indicated markedly different composition than clots extracted from wild-type mice. In wild-type clots, fibrin and polyhedral erythrocytes formed a large proportion of the total structures. In contrast, clots from rFVIIa-treated HemA mice consisted primarily of platelets and erythrocytes with forms intermediate between discoid and polyhedral but, surprisingly, low fibrin content. Taken together, these data suggest that rFVIIa-mediated clot formation may require greater activated platelet involvement, which would be consistent with the TF-independent mechanism of action proposed for rFVIIa in HemA. Finally, the compositional difference between clots from wild-type versus HemA mice dosed with rFVIIa suggest that evaluating HemA therapies for their ability to form more physiologic clots could be an approach to improve treatment options for patients with HemA. Disclosures Leong: Bayer: Employment. Xu:Bayer: Employment. Mallari:Bayer: Employment. Wong:Bayer: Employment. Sim:Bayer: Employment. Cuker:Stago: Consultancy; Genzyme: Consultancy; Amgen: Consultancy; Biogen-Idec: Consultancy, Research Funding; T2 Biosystems: Research Funding. Marturano:T2 Biosystems: Employment. Lowery:T2 Biosystems: Employment. Kauser:Bayer: Employment. Weisel:Bayer: Research Funding.

Download Full-text

MAF1 is a Chronic Repressor of RNA Polymerase III Transcription in the Mouse

10.1101/775353 ◽

2019 ◽

Cited By ~ 4

Author(s):

Nicolas Bonhoure ◽

Viviane Praz ◽

Robyn D. Moir ◽

Gilles Willemin ◽

François Mange ◽

...

Keyword(s):

Energy Expenditure ◽

Rna Polymerase ◽

Ribosomal Proteins ◽

Rna Polymerase Iii ◽

Mrna Levels ◽

Wild Type ◽

Pol Iii ◽

The Impact ◽

Global Translation ◽

Modest Effect

AbstractMaf1-/- mice are lean, obesity-resistant and metabolically inefficient. Their increased energy expenditure is thought to be driven by a futile RNA cycle that reprograms metabolism to meet an increased demand for nucleotides stemming from the deregulation of RNA polymerase (pol) III transcription. Metabolic changes consistent with this model have been reported in both fasted and refed mice, however the impact of the fasting-refeeding-cycle on pol III function has not been examined. Here we show that changes in pol III occupancy in the liver of fasted versus refed wild-type mice are largely confined to low and intermediate occupancy genes; high occupancy genes are unchanged. However, in Maf1-/- mice, pol III occupancy of the vast majority of active loci in liver and the levels of specific precursor tRNAs in this tissue and other organs are higher than wild-type in both fasted and refed conditions. Thus, MAF1 functions as a chronic repressor of active pol III loci and can modulate transcription under different conditions. Our findings support the futile RNA cycle hypothesis, elaborate the mechanism of pol III repression by MAF1 and demonstrate a modest effect of MAF1 on global translation via reduced mRNA levels and translation efficiencies for several ribosomal proteins.

Download Full-text

Gene Therapy in Hemophilia: An Assessment of Hematologists' Knowledge Gaps and Attitudes

Blood ◽

10.1182/blood-2018-99-119116 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 3485-3485 ◽

Cited By ~ 3

Author(s):

Simi Hurst ◽

Charlotte Warren ◽

K. John Pasi

Keyword(s):

Gene Therapy ◽

Research Funding ◽

Hemophilia A ◽

Viral Vector ◽

Healthcare Providers ◽

Factor Ix ◽

Educational Activity ◽

Knowledge Gaps ◽

Endogenous Expression ◽

Therapy Strategies

Abstract BACKGROUND: Currently available treatments for hemophilia A and B require frequent intravenous infusions. Gene therapy, by contrast, offers the hope of a functional cure through endogenous expression of the factor VIII or factor IX genes. To identify and address practice gaps among healthcare providers who manage patients with hemophilia, a collaboration between the National Hemophilia Foundation (NHF), European Haemophilia Consortium (EHC), World Federation of Hemophilia (WFH), and Medscape Education was established. The objective of the current study is to assess clinicians' needs with regard to understanding the science and mechanism for gene therapy, the different technologies being proposed, identifying candidates for gene therapy, disease areas for which gene therapy is being explored, and the latest data on the potential role of gene therapy in hemophilia A and B. METHODS: A continuing medical education (CME)-certified clinical practice assessment comprising 25 multiple choice questions that measured knowledge, attitudes, and perspectives about gene therapy was developed. The survey instrument was made available online to physicians without monetary compensation or charge. Respondent confidentiality was maintained and responses were de-identified and aggregated prior to analyses. The activity launched on March 03, 2018; data through July 27, 2018 are presented, but data collection is ongoing. RESULTS: At the time of this analysis, 194 physician participants indicated that they actively manage patients with hemophilia. Demographics are presented in Table 1; confidence and attitudes about gene therapy in Table 2. Among hematologists/oncologists (n=54; hem/onc), identified knowledge gaps include, 46% could not identify the liver as the tissue/cell type that is the primary target for gene therapy in hemophilia46% thought that current approaches to gene therapy in hemophilia involved some form of host gene editing39% did not realize that gene therapy strategies only affect somatic cells and not the germline22% thought current gene therapy strategies would prevent or reduce the severity of hemophilia in subsequent generations of patients33% were unable to correctly identify adeno-associated virus (AAV) as the viral vector that is the current basis for the majority of gene therapy trials in hemophilia81% had misconceptions regarding the key characteristics of the AAV vector56% did not recognize that the AAV vector does not routinely integrate into the host genome19% were unfamiliar with the maximum gene cassette capacity of AAV57% were unfamiliar with the results from the pivotal University College London (UCL)/St Jude trial of scAAV2/8-LP1-hFIXcovector in patients with hemophilia B63% were unfamiliar with the clinical trial data for SPK-8011 in hemophilia A67% were unfamiliar with the results at the 12 month time-point for valoctocogene roxaparvovec in hemophilia A trials57% had misconceptions with regard to the causes for and treatment of ALT elevations seen in hemophilia AAV gene therapy trials CONCLUSIONS: Gene therapy has the potential to fundamentally alter the management of hemophilia. This educational activity identified clear deficits about - and attitudes toward - gene therapy among healthcare providers who currently care for patients with hemophilia. Furthermore, the great majority of healthcare providers lacked confidence in their understanding of gene therapy for hemophilia A. These findings will be used to inform the development of educational programs and to prepare providers for anticipated changes to the hemophilia treatment landscape. Disclosures Pasi: Catalyst Bio: Honoraria; Octapharma: Honoraria; NovoNordisk: Speakers Bureau; Bioverativ: Honoraria, Research Funding; Apcintex: Honoraria; Shire: Speakers Bureau; Bayer: Speakers Bureau; Pfizer: Speakers Bureau; Sobi: Honoraria; Biomarin: Honoraria, Research Funding; Alnylam: Honoraria, Research Funding.

Download Full-text

An Insight into the Impact of Hemophilia a on Daily Life According to Disease Severity: A Preliminary Analysis of the CHESS II Study

Blood ◽

10.1182/blood-2020-136952 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 1-3

Author(s):

Declan Noone ◽

Francis Nissen ◽

Tao Xu ◽

Tom Burke ◽

Sohaib Asghar ◽

...

Keyword(s):

Board Of Directors ◽

Disease Severity ◽

Research Funding ◽

Hemophilia A ◽

Daily Life ◽

Social Activity ◽

Publicly Traded ◽

Advisory Committees ◽

On Demand ◽

The Impact

Introduction: Hemophilia A (HA) is a congenital bleeding disorder caused by a deficiency in clotting factor VIII (FVIII). There are currently limited data on the impact of HA on daily life. Here we examine the impact of HA on the daily life of adult persons with HA (PwHA) without current FVIII inhibitors according to disease severity. Methods: The Cost of Haemophilia in Europe: a Socioeconomic Survey II (CHESS II) is a retrospective, burden-of-illness study in adults with mild, moderate, and severe HA or hemophilia B (defined by endogenous FVIII/IX [IU/dL] relative to normal; mild, 5-<40%; moderate, 1-5%; severe, <1%); this analysis includes only PwHA. Male participants (aged ≥18 years) diagnosed with HA (without FVIII inhibitors) at least 12 months prior to clinical consultation were enrolled from Denmark, France, Germany, Italy, the Netherlands, Romania, Spain, and the UK. Data on clinical outcomes and healthcare resource utilization were captured via electronic case report forms disseminated to hemophilia specialists. PwHA completed a paper-based questionnaire utilizing 5-point Likert scales to assess the disease burden on their daily life. Overall, 12 months' retrospective data were examined. Informed consent was obtained and the study was approved by the University of Chester ethical committee. Results: Of 258 PwHA completing questionnaires, 15.9% (n=41), 27.9% (n=72), and 56.2% (n=145) had mild, moderate, and severe HA, respectively. Of those with severe HA, 60.0% were currently receiving FVIII prophylaxis (standard of care for severe HA); in comparison, 4.9% and 6.9% of those with mild and moderate HA were receiving prophylaxis (Table 1). Treatment adaptation in anticipation of physical or social activity was reported by 19.5%, 23.6%, and 38.6% of those with mild, moderate, and severe HA, respectively. Over a third of participants with mild (36.6%) and moderate (44.4%) HA, and 64.8% of those with severe HA (58.6% with severe HA receiving on-demand treatment and 69.0% receiving prophylaxis) agreed or strongly agreed that HA had reduced their physical activity (Figure 1). Overall, 38.9% of those with moderate HA and 58.6% of those with severe HA (63.8% with severe HA receiving on-demand treatment and 55.2% receiving prophylaxis) agreed or strongly agreed that their HA had reduced their social activity; this was less pronounced in mild HA (9.8%). Additionally, 31.7%, 36.1%, and 64.1% of those with mild, moderate, and severe HA (62.1% with severe HA receiving on-demand treatment and 65.5% receiving prophylaxis) agreed or strongly agreed that their HA had caused them to miss opportunities. Correspondingly, frustration due to HA was felt by 19.5%, 34.7% and 57.9% (56.9% with severe HA receiving on-demand treatment and 58.6% receiving prophylaxis) of people, respectively. When asked whether they believed their daily life was compromised due to their hemophilia, 24.4%, 37.5%, and 63.4% of those with mild, moderate, and severe HA, respectively, agreed. Pain, as reported by the physician, was noted in 36.6% of people with mild HA (100% was reported as 'mild'); in people with moderate HA, pain was reported as 'mild', 'moderate', and 'severe' in 44.4%, 20.8%, and 1.4% of PwHA, respectively. In people with severe HA, pain was reported as 'mild', 'moderate', and 'severe' in 39.7%, 27.6%, and 8.6% for those receiving on-demand treatment, and 37.9%, 32.2%, and 8.0% for those receiving prophylaxis, respectively. Conclusions: In all disease severity groups, there was a notable group of PwHA that felt that they have had to reduce their physical and social activity, have had fewer opportunities and are frustrated due to their disease. While the impact on daily life is most pronounced in people with severe HA (including those receiving on-demand treatment and those receiving prophylaxis), it is also apparent in mild and moderate HA, indicating that there may be an unmet medical need in these groups. Disclosures Noone: Healthcare Decision Consultants: Membership on an entity's Board of Directors or advisory committees; Research Investigator PROBE: Research Funding; European Haemophilia Consortium: Membership on an entity's Board of Directors or advisory committees. Nissen:F. Hoffmann-La Roche Ltd: Current Employment; Actelion: Consultancy; Novartis: Research Funding; GSK: Research Funding. Xu:F. Hoffmann-La Roche Ltd: Current Employment, Other: All authors received support for third party writing assistance, furnished by Scott Battle, PhD, provided by F. Hoffmann-La Roche, Basel, Switzerland.. Burke:University of Chester: Current Employment; HCD Economics: Current Employment; F. Hoffmann-La Roche Ltd: Consultancy. Asghar:HCD Economics: Current Employment. Dhillon:F. Hoffmann-La Roche Ltd: Other: All authors received editorial support for this abstract, furnished by Scott Battle, funded by F. Hoffmann-La Roche Ltd, Basel, Switzerland. ; HCD Economics: Current Employment. Aizenas:F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company. Meier:F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company. O'Hara:HCD Economics: Current Employment, Current equity holder in private company; F. Hoffmann-La Roche Ltd: Consultancy. Khair:Biomarin: Consultancy; HCD Economics: Consultancy; Novo Nordisk: Consultancy, Membership on an entity's Board of Directors or advisory committees; Medikhair: Membership on an entity's Board of Directors or advisory committees; Sobi: Consultancy, Honoraria, Research Funding, Speakers Bureau; CSL Behring: Honoraria, Research Funding; F. Hoffmann-La Roche Ltd: Honoraria, Research Funding; Takeda: Honoraria, Speakers Bureau; Bayer: Consultancy, Honoraria, Speakers Bureau; Haemnet: Membership on an entity's Board of Directors or advisory committees.

Download Full-text

Development And Application Of A Minimal-Adenoviral Vector System For Gene Therapy Of Hemophilia A

Thrombosis and Haemostasis ◽

10.1055/s-0037-1615881 ◽

1999 ◽

Vol 82 (08) ◽

pp. 562-571 ◽

Cited By ~ 14

Author(s):

Steven Josephs ◽

Jiemin Zhou ◽

Xiangming Fang ◽

Ramón Alemany ◽

Cristina Balagué ◽

...

Keyword(s):

Gene Therapy ◽

Factor Viii ◽

Human Factor ◽

Hemophilia A ◽

Vector System ◽

High Level Expression ◽

Viral Particles ◽

Human Factor Viii ◽

High Level

IntroductionHemophilia A and B are the most common bleeding disorders caused by deficiencies of clotting factors VIII and IX, respectively, both of which are X-linked with a recessive heredity.1 Replacement of the deficient factors with frequent intravenous injections of plasma concentrates or recombinant proteins is the standard treatment for these diseases.2 Great efforts have been made for nearly a decade toward developing experimental gene therapy for these diseases and aiming at the development of a medical intervention that is more effective and convenient than the currently available replacement therapies.3 Hemophilia is a suitable clinical model for the development of gene therapy products and has a number of advantages: 1) there is a simple and well defined cause-and-effect relationship between the protein deficiencies and bleeding symptoms; 2) tissue-specific expression and precise regulation of the transgenes are not necessary; 3) well characterized animal models are available for preclinical studies; 4) an unequivocal endpoint for product efficacy can be assessed in clinical trials; and 5) even 1% to 5% of the normal physiological levels of the proteins is therapeutic.For gene therapy of hemophilia, the most challenging hurdle, with respect to the long-term expression of the deficient proteins at adequate levels, is the development of a suitable gene delivery system. Technologies have been evolving from ex vivo to in vivo approaches, from initial use of retroviral vector to recent application of adenviral (Ad) or adeno-associated virus (AAV) vector, demonstrating progress from early results of transient low-level expression to more sustained high-level expression.3 For hemophilia A treatment, Ad vectors are particularly useful, since the liver naturally produces factor VIII, and following intravenous (i.v.) injection, Ad vectors concentrate in the liver. This makes the gene transduction efficiency to liver very high. Adenovirus vectors have been developed for gene therapy due to their high titer, broad infectivity, potential for large payload, and in vivo gene delivery capacity.4 Although the immunogenicity and cytotoxicity associated with the early-generation Ad vectors have been a concern with respect to their clinical application, newly developed vectors, in which the viral coding sequences have been deleted, have significantly reduced the side effects associated with the vectors. The “gutless” Ad vector, or so called helper-dependent, large-capacity, or mini- Ad vectors are the representative examples of these new-generation Ad vectors.5-15 The mini-Ad vector system described in this report was developed based on two major research findings. First, an Ad- SV40 hybrid virus discovered during attempts to grow human Ad in non-permissive monkey COS-7 cells.16 The hybrid virus had a genome structure in which only both ends of the Ad sequences were retained and almost all coding sequences of the Ad genome were replaced by symmetric, tandemly repeated SV40 genomes. The hybrid viruses replicated and were packaged in the presence of a wild-type Ad as a helper. This finding implied that total replacement of the Ad genome was possible to form a mini-Ad vector as long as proper helper function and selective pressure was provided. Secondly, it was discovered that Ad packaging can be attenuated by deleting portions of the packaging signal.17 This finding provided a means to put selective pressure on the helper Ad (referred to as ancillary Ad) by specifically limiting its packaging process and allowing a preferential packaging of the mini-Ad. The system, therefore, is designed to have three main components: the mini-Ad vector, the E1-deleted ancillary Ad, and a production cell line that provides AdE1 complementation.Based on the mini-Ad vector system, MiniAdFVIII was developed. The MiniAdFVIII vector carries a 27 kb expression cassette, in which the full-length human factor VIII cDNA is flanked by a human albumin promoter and cognate genomic sequences. Infection of MiniAdFVIII in vitro showed that the vector mediated expression of functional human factor VIII at levels of 100-200 ng/106 cells per 24 hours in HepG2 and 293 cells. With single-dose intravenous injection of 1011 viral particles in hemophilic mice, MiniAdFVIII produced a sustained high-level expression of human factor VIII (at 100-800 ng/ml for up to 369 days) that corrected the factor VIII-deficient phenotype. Safety studies of MiniAdFVIII showed that there were no significant toxicities in mice and dogs after a single intravenous dose of up to 3×1011 and 6×1012 viral particles, respectively. In this report, other studies for developing the MiniAdFVIII vector with a site-specific integration capability and the development of a human factor VIII-tolerized mouse model for preclinical studies of MiniAdFVIII are described.

Download Full-text

Mycobacterium tuberculosis Requires Cholesterol Oxidase to Disrupt TLR2 Signalling in Human Macrophages

Mediators of Inflammation ◽

10.1155/2019/2373791 ◽

2019 ◽

Vol 2019 ◽

pp. 1-17

Author(s):

Izabela Szulc-Kielbik ◽

Michal Kielbik ◽

Patrycja Przygodzka ◽

Anna Brzostek ◽

Jaroslaw Dziadek ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Cholesterol Oxidase ◽

Interleukin 10 ◽

Signalling Pathway ◽

Mrna Levels ◽

Dependent Manner ◽

Wild Type ◽

Human Macrophages ◽

Protein Levels ◽

The Impact

This study tested the hypothesis that Mycobacterium tuberculosis (Mtb) uses a cholesterol oxidase enzyme (ChoD) to suppress a toll-like receptor type 2- (TLR2-) dependent signalling pathway to modulate macrophages’ immune response. We investigated the impact of Mtb possessing or lacking ChoD as well as TBChoD recombinant protein obtained from Mtb on the expression and activation of two key intracellular proteins involved in TLR2 signalling in human macrophages. Finally, the involvement of TLR2-related signalling proteins in an inflammatory/immunosuppressive response of macrophages to Mtb was evaluated. We demonstrate that wild-type Mtb but not the ∆choD mutant decreased the cytosolic IRAK4 and TRAF6 protein levels while strongly enhancing IRAK4 and TRAF6 mRNA levels in macrophages. Our data show that the TLR2 present on the surface of macrophages are involved in disturbing the signalling pathway by wild-type Mtb. Moreover, recombinant TBChoD effectively decreased the cytosolic level of TRAF6 and lowered the phosphorylation of IRAK4, which strongly confirm an involvement of cholesterol oxidase in affecting the TLR2-related pathway by Mtb. Wild-type Mtb induced an immunosuppressive response of macrophages in an IRAK4- and TRAF6-dependent manner as measured by interleukin 10 production. In conclusion, ChoD is a virulence factor that enables Mtb to disturb the TLR2-related signalling pathway in macrophages and modulate their response.

Download Full-text

Gene Therapy for Hemophilia: a review on clinical benefit, limitations and remaining issues

Blood ◽

10.1182/blood.2019003777 ◽

2021 ◽

Author(s):

Frank W.G. Leebeek ◽

Wolfgang Miesbach

Keyword(s):

Gene Therapy ◽

Clinical Benefit ◽

Hemophilia A ◽

Phase 1 ◽

Successful Outcome ◽

Severe Hemophilia ◽

The Past ◽

Therapy Studies ◽

The Impact ◽

Made In

In the past decade enormous progress has been made in the development of gene therapy for hemophilia A and B. After the first encouraging results of intravenously administered AAV-based liver-directed gene therapy in patients with severe hemophilia B were reported in 2011, many gene therapy studies have been initiated. Most of these studies, using AAV vectors with various gene constructs, showed sufficient FVIII and FIX expression in patients to significantly reduce the number of bleeds and the need for prophylaxis in the fast majority of the severe hemophilia patients. This resulted in great clinical benefit for nearly all patients. In this review we will summarize the most recent findings of reported and ongoing gene therapy trials. We will highlight the successful outcome of trials with focus on the results of recently reported phase 1 trials and preliminary results of phase 2b/3 trials for hemophilia A and B. These new reports also reveal the impact of side effects and drawbacks associated with gene therapy. We will therefore also discuss the limitations and remaining issues of the current gene therapy approaches. These issues have to be resolved before gene therapy will be widely available for the hemophilia patient population.

Download Full-text