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Gene therapy for hemophilia is designed to produce health gains for patients over many years. Rewarding that value creation on the basis of a one-time treatment implies a large upfront cost. This cost can only be justified by long-term health benefits and being cost-effective compared with conventional treatments. Yet, uncertainties about the long-term benefits make it challenging to assess clinical and economic value of gene therapies at launch. We identify and discuss key methodological challenges in assessing the value of gene therapy for hemophilia, including the immaturity of evidence on the durability of benefits, lack of definition and valuation of cure for chronic diseases, absence of randomized controlled trials, limitations of traditional quality of life measures in hemophilia, approach for qualifying cost-savings compared with current treatments, and choice of perspective. The Institute for Clinical and Economic Review has developed a framework for assessing single or short-term therapies (ICER-SST) and has applied it in hemophilia. After reviewing this framework and its application, we recommend the following when assessing the value of hemophilia gene therapies: (1) leveraging expert clinical opinion to justify assumptions on the durability of benefits; (2) using external synthetic controls and lead-in, self-controlled trials to assess comparative effectiveness; (3) addressing limitations of traditional quality of life measures through the use of modified utility collection approaches; (4) adjusting cost offsets from gene therapies with caution; (5) considering outcome-based contracting to address uncertainties about prices and long-term outcomes; and (6) presenting societal and healthcare system perspectives in parallel.

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.

Hemophilia B (HB) is a rare congenital disorder characterized by bleeding-related complications which are managed by prophylactic or post-bleeding event ("on-demand") replacement of clotting factor IX (FIX). The standard of care for severe HB is life-long prophylaxis with standard half-life (SHL) or extended half-life (EHL) products given every 2-3 or 7-14 days, respectively. FIX treatment costs in the US have been investigated, but the lifetime costs of HB treatment have not been well characterized, particularly related to the impact of joint health deterioration and associated health resource utilization. We developed a decision-analytic model to explore outcomes, costs and underlying cost drivers associated with FIX treatment options over the lifetime of an adult with severe or moderately severe HB.With participation from clinicians, health technology assessment specialists and patient advocates, a Markov model was constructed to estimate bleeding events and costs associated with health states including "bleed into joint", "bleed not into joint", "no bleed" and "death". Sub-models of joint health were based on 0, 1, or ≥2 areas of chronic joint damage. US third-party payer and societal perspectives were considered with a lifetime horizon; sensitivity analyses tested the robustness of primary findings.Total adult lifetime costs per patient with severe and moderately severe HB were $21,086,607 for SHL FIX prophylaxis, $22,987,483 for EHL FIX prophylaxis, and $20,971,826 for on-demand FIX treatment. For FIX prophylaxis, the cost of FIX treatment accounts for90% of the total HB treatment costs.This decision analytic model demonstrated significant economic burden associated with the current HB treatment paradigm.

As gene transfer with adeno-associated virus (AAV) vectors is starting to enter clinical practice, this review examines the impact of vector capsid choice in liver-directed gene transfer for hemophilia. Given that there are multiple clinical trials completed and ongoing in this field, it is important to review the clinical evidence, particularly as a range of AAV-vector serotypes including AAV2, AAV5, AAV8, and AAV10 have been tested. Although there have been a number of successful trials, the development of two investigational AAV vectors for hemophilia B has been discontinued because they did not meet efficacy and/or safety expectations. Whether this difference between success and failure of gene transfer approaches reflects capsid choice, vector design, manufacturing system, or other variables is a question of great interest. Here, we examine the body of evidence across trials to determine the possible influences of serotype choice on key clinical outcomes such as safety, vector clearance, treatment eligibility, occurrence of transaminase elevations, activation of capsid-directed cytotoxic T cell responses, and clinical efficacy. In summary, gene transfer requires a balance between achieving sufficient transgene expression and minimizing destructive immune responses, which may be affected by AAV-vector serotype choice.

INTRODUCTION Gene therapy has shown promise in clinical trials for patients with haemophilia, but patient preference studies have focused on factor replacement treatments. AIM We conducted a discrete choice experiment (DCE) to investigate the relative importance and differential preferences patients provide for gene therapy attributes. METHODS We surveyed male adults with haemophilia in the United States recruited from patient panels including the National Hemophilia Foundation Community Voices in Research platform using an online survey over 4 months in 2020/21. Participants indicated preferences for gene therapy attributes including dosing frequency/durability, effect on annual bleeding, uncertainty related to side effects, impact on daily activities, impact on mental health, and post-treatment requirements. The relative importance of each attribute was analysed overall and for subgroups based on haemophilia type and severity. RESULTS A total of 183 males with haemophilia A (n = 120) or B (n = 63) were included. Half (47%) had severe haemophilia; most (75%) were White. Overall, participants gave effect on bleeding rate the greatest relative importance (31%), followed by dose frequency/durability (26%), uncertainty regarding safety issues (17%), and impact on daily activities (11%). Dose frequency/durability had the greatest importance for those with haemophilia B (35%). CONCLUSION People with haemophilia prioritised reduced bleeding and treatment burden; the former was more important in haemophilia A and the latter in haemophilia B, followed by safety and impact on daily life in this DCE of gene therapy attributes. These findings and differences can inform clinical and health policy decisions to improve health equity for people with haemophilia.

IntroductionPeople with inherited and long-term conditions such as haemophilia have been shown to adapt to their levels of disability, often reporting better quality of life (QoL) than expected from the general population (the disability paradox).AimTo investigate the disability paradox in people with haemophilia in the United States by examining preference differences in health state valuations versus the general population.MethodsWe conducted a discrete choice experiment including duration to capture valuations of health states based on patient-reported preferences. Participants indicated their preferences for hypothetical health states using the EQ-5D-5L, where each participant completed 15 of the 120 choice tasks. Response inconsistencies were evaluated with dominated and repeated scenarios. Conditional-logit regressions with random sampling of the general population responses were used to match the sample of patients with haemophilia. We compared model estimates and derived preferences associated with EQ-5D-5L health states.ResultsAfter removing respondents with response inconsistencies, 1327/2138 (62%) participants remained (177/283 haemophilia; 1150/1900 general population). Patients with haemophilia indicated higher preference value for 99% of EQ-5D-5L health states compared to the general population (when matched on age and gender). The mean health state valuation difference of 0.17 indicated a meaningful difference compared to a minimal clinically important difference threshold of 0.07. Results were consistent by haemophilia type and severity.ConclusionOur findings indicated the presence of a disability paradox among patients with haemophilia, who reported higher health states than the general population, suggesting the impact of haemophilia may be underestimated if general population value sets are used.

Background: In recent years, pharmacological strategies have implicated α3 subunit-containing GABAA (α3GABAA) receptor subtypes in the anxiety-reducing effects of benzodiazepines, whereas transgenic mouse approaches have implicated α2 or α5 subunit-containing GABAA receptors. Aims: We investigated the role of α3GABAA subtypes in benzodiazepine-induced behaviors by evaluating the anti-conflict, reinforcing, and sedative-motor effects of the novel compound YT-III-31, which has functional selectivity for α3GABAA receptors. Methods: Female and male rhesus monkeys were trained under a conflict procedure ( n = 3), and a progressive-ratio schedule of reinforcement with midazolam as the training drug ( n = 4). Sedative-like behavior was assessed using a quantitative behavioral observation procedure ( n = 4). A range of doses of YT-III-31 was administered in all tests using the i.v. route of administration. Results: In the conflict procedure, increasing doses of YT-III-31 resulted only in dose-dependent attenuation of non-suppressed responding. In the progressive-ratio model of self-administration, YT-III-31 maintained average injections/session above vehicle levels at 0.1 and 0.18 mg/kg/injection. In quantitative observation procedures, YT-III-31 engendered mild sedative effects (“rest/sleep posture”), and deep sedation at the highest dose tested (5.6 mg/kg, i.v.), along with a suppression of tactile/oral exploration and increased observable ataxia. In contrast to other benzodiazepine-like ligands, YT-III-31 uniquely engendered a biphasic dose-response function for locomotion and suppressed self-groom. Conclusions: The finding that YT-III-31 lacked anti-conflict properties is in accordance with transgenic mouse research indicating no role for α3GABAA subtypes in benzodiazepine-mediated anxiety reduction. Instead, our results raise the possibility of a role for α3GABAA receptors in the abuse potential and sedative effects of benzodiazepine-type drugs.

Etranacogene dezaparvovec (AMT-061) is a recombinant AAV5 vector including a gene cassette containing the factor IX (FIX) Padua variant under the control of a liver-specific promoter. A phase 2b study was conducted to confirm that a single dose of 2 × 1013 genome copies per kilogram of etranacogene dezaparvovec will result in FIX activity ≥5% 6 weeks after dosing. Secondary end points included FIX activity at other time points, bleed frequency, FIX replacement, and safety. Etranacogene dezaparvovec was administered as a single IV infusion to 3 adults with severe to moderately severe hemophilia B. Before treatment, participants had low levels of preexisting neutralizing antibodies to AAV5. This article reports a planned 26-week interim assessment. At week 6, mean FIX activity was 31% (23.9%-37.8%), increasing to 47% (33.2%-57.0%) at 26 weeks, with 2 subjects exhibiting sustained activity >40%. Consistent with the FIX activity, etranacogene dezaparvovec was associated with a complete bleed cessation with no need for FIX replacement therapy up to 26 weeks. Etranacogene dezaparvovec was generally well tolerated. No clinically significant elevations in levels of liver enzymes or inflammatory markers were observed, and no use of corticosteroids related to treatment was required. In individuals with severe to moderately severe hemophilia B, etranacogene dezaparvovec resulted in clinically relevant increases in FIX activity, cessation of bleeds, and abrogation of the need for FIX replacement, despite the presence of preexisting anti-AAV5 neutralizing antibodies detected by using a highly sensitive luciferase assay. Consistency of results in the 3 participants supported an expanded evaluation of the safety/efficacy of etranacogene dezaparvovec in the HOPE-B (Health Outcomes With Padua Gene; Evaluation in Hemophilia-B) phase 3 trial. The current trial was registered at www.clinicaltrials.gov as #NCT03489291.

Background: Etranacogene dezaparvovec is an investigational gene therapy for hemophilia B (HB) comprising an adeno-associated virus serotype 5 (AAV5) vector containing a codon-optimized Padua variant human factor IX (FIX) gene with a liver specific promoter. In a Phase 2b study, a single dose of etranacogene dezaparvovec provided mean FIX activity of 41.0% sustained at 1yr post-dose in 3 participants (pts). Although most gene therapy clinical studies exclude pts with pre-existing neutralizing antibodies (NAbs) to the capsid serotype, early clinical studies and nonhuman primate data suggest that generally prevalent titers of anti-AAV5 NAbs may not preclude successful transduction with etranacogene dezaparvovec. Aims: A Phase 3, Health Outcomes with Padua gene; Evaluation in Hemophilia B (HOPE-B; NCT03569891) was established to further assess efficacy and safety of etranacogene dezaparvovec in adults with HB with a wide range of pre-existing NAbs to AAV5. Here we report outcomes at 26 weeks (wks). Methods: HOPE-B is a Phase 3, open-label, single-dose, single-arm, multi-national trial in adult males with severe or moderate-severe HB (FIX≤2%). All pts received routine FIX prophylaxis prior to study. Pts were not excluded based on pre-existing NAbs to AAV5. Pts entered a prospective lead-in period of at least 6 months during which bleeding/factor use was monitored, then received a single intravenous dose of etranacogene dezaparvovec (2x1013 gc/kg). Pts will be followed for 5yrs. Primary endpoints comprised FIX activity (one stage) at 26 and 52wks after dosing and 52wk annualized bleeding rate. For pts with no clean post-treatment FIX samples (≥10d post exogenous FIX), factor activity was imputed as baseline value based on historic disease severity. Secondary endpoints include factor replacement use, adverse events (AEs), and reactive use of corticosteroids. Results: 75 pts were screened, of whom 67 entered lead-in. 54 pts were dosed (44 severe, 10 moderately severe HB) and completed 26wks of follow-up. Mean age (±SD) was 41.5 (15.8) yrs. 38/54 pts (70.4%) had bleeds (n=123) during the lead-in despite prophylaxis, and 23/54 (42.6%) had NAbs to AAV5 at baseline (max titer: 3212.3). Following treatment, FIX activity increased rapidly to a mean (SD; min,max) of 37.2% (±19.6; 1.0, 97.1) at wk26, representing a mean (SD; min,max) change from baseline of 36.0% (±19.7; 0, 96.1 p Conclusions: The first co-primary endpoint of this study was met. This is the first report of a Phase 3 study in HB and the largest gene therapy trial cohort to date. Following a single dose of etranacogene dezaparvovec, FIX activity increased, without the need for prophylactic immunosuppression, into the mild-to-normal range at 26wks in pts with severe/moderately severe HB. Importantly, this included pts with titers of pre-existing anti-AAV5 NAbs. Pts were able to discontinue prophylaxis and bleeding was abolished in the majority. The safety profile was consistent with early phase AAV5 studies and together these data support a favorable safety and efficacy profile for etranacogene dezaparvovec Disclosures Pipe: HEMA Biologics: Consultancy, Other; Catalyst Biosciences: Consultancy; CSL Behring: Consultancy; ApcinteX: Consultancy; Bayer: Consultancy, Other: Contracted Research; BioMarin: Consultancy, Other: Contracted Research; Takeda: Consultancy; uniQure: Consultancy, Other; Siemens: Other; Pfizer: Consultancy; Freeline Therapeutics: Consultancy, Other: Contracted Research; Novo Nordisk: Consultancy, Other: Contracted Research; Roche/Genentech: Consultancy, Other: Contracted Research; Sangamo Therapeutics: Consultancy; Sanofi Genzyme: Consultancy, Other; Spark Therapeutics: Consultancy. Recht:CSL Behring: Consultancy, Other: personal fees; Genentech: Consultancy, Other: personal fees, Research Funding; Pfizer: Consultancy, Other: personal fees, Research Funding; BioMarin: Research Funding; Takeda: Consultancy, Other: personal fees, Research Funding; uniQure: Consultancy, Other: personal fees, Research Funding; Novo Nordisk: Consultancy, Other: personal fees, Research Funding; Spark: Research Funding; Bayer: Research Funding; Grifols: Research Funding; Hema Biologics: Consultancy, Research Funding; LFB: Research Funding; Octapharma: Research Funding; Catalyst Biosciences: Consultancy; Kedrion: Consultancy; Sanofi: Consultancy, Research Funding. Key:Uniqure: Consultancy; Grifols: Research Funding; Takeda: Research Funding; Novo Nordisk: Other: Chair of Grants Committee. Leebeek:Shire/Takeda: Research Funding; uniQure: Consultancy; Shire/Takeda: Consultancy; BioMarin: Consultancy; SOBI: Other: Travel grant; Roche: Other: DSMB member for a study; CSL Behring: Research Funding. Castaman:Bayer, Roche, Sobi, Grifols, Novo Nordick, Werfen, Kedrion: Consultancy, Honoraria, Speakers Bureau; CSL Behring, Pfizer, Sobi: Research Funding; Ablynx, Alexion, Bayer, Takeda, CSL Behring, Novo Nordisk, Pfizer, Roche,Sanofi, SOBI, uniQure: Membership on an entity's Board of Directors or advisory committees. Lattimore:uniQure: Other: Study Steering Committee member. Van Der Valk:Baxalta: Research Funding. Peerlinck:Bayer: Consultancy, Research Funding; CSL Behring: Consultancy, Research Funding; NovoNordisk: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Roche: Research Funding; Sobi: Consultancy; Takeda: Consultancy, Research Funding. Coppens:Roche: Research Funding; Portola/Alexion: Research Funding; Sanquin Blood Supply: Research Funding; uniQure: Research Funding; NovoNordisk: Consultancy; Pfizer: Consultancy; Sobi: Consultancy; Medcon International: Consultancy; MEDtalks: Consultancy; Bayer: Consultancy, Research Funding; CSL Behring: Consultancy, Research Funding; Daiichi Sankyo: Research Funding. O'Connell:uniQure: Consultancy; F. Hoffmann-La Roche Ltd, Novo Nordisk, SOBI: Speakers Bureau; SOBI: Research Funding. Pasi:Sanofi: Honoraria, Other: Personal fees and nonfinancial support; honoraria as member of scientific advisory boards and symposia, Research Funding; BioMarin: Consultancy, Honoraria, Other: Grants, personal fees, and nonfinancial support; honoraria as member of scientific advisory boards and symposia, Research Funding; uniQure: Other: Grants and nonfinancial support , Research Funding; ApcinteX: Consultancy, Other: Personal fees ; Takeda: Consultancy, Honoraria, Other: Personal fees; honoraria as member of scientific advisory boards and symposia ; Biotest: Consultancy, Honoraria, Other: Personal fees and nonfinancial support; honoraria as member of scientific advisory boards and symposia; Catalyst Biosciences: Consultancy, Other: Personal fees and nonfinancial support; honoraria as member of scientific advisory boards and symposia; Novo Nordisk: Honoraria, Other: Personal fees and nonfinancial support; honoraria as member of scientific advisory boards and symposia ; Octapharma: Honoraria, Other: Personal fees and nonfinancial support; honoraria as member of scientific advisory boards and symposia , Speakers Bureau; Roche: Honoraria, Other; Sobi: Consultancy, Honoraria, Other; Tremeau: Consultancy. Kampmann:Uniqure: Research Funding, Speakers Bureau; Shire Pharmaceuticals: Speakers Bureau. Meijer:Pfizer: Research Funding; Sanquin: Speakers Bureau; Bayer: Speakers Bureau; Sanquin: Research Funding; Bayer: Research Funding; Boehringer Ingelheim: Speakers Bureau; BMS: Speakers Bureau; Aspen: Speakers Bureau; Uniqure: Consultancy. von Drygalski:Biomarin: Consultancy; Bioverativ/Sanofi Genzyme: Consultancy; NovoNordisk: Consultancy; Pfizer: Consultancy; uniQure: Consultancy; Hematherix Inc.: Membership on an entity's Board of Directors or advisory committees. Young:Genentech/Roche, Grifols, and Takeda: Research Funding; BioMarin, Freeline, Genentech/Roche, Grifols, Kedrion, Novo Nordisk, Sanofi Genzyme, Spark, Takeda, and UniQure: Honoraria; Bayer, CSL Behring, Freeline, UniQure: Consultancy. Hermans:WFH: Other; EAHAD: Other; LFB: Consultancy, Speakers Bureau; CSL Behring: Consultancy, Speakers Bureau; CAF-DCF: Consultancy, Speakers Bureau; Biogen: Consultancy, Speakers Bureau; Sobi: Consultancy, Research Funding, Speakers Bureau; Shire, a Takeda company: Consultancy, Research Funding, Speakers Bureau; Pfizer: Consultancy, Research Funding, Speakers Bureau; Bayer: Consultancy, Research Funding, Speakers Bureau; Novo Nordisk: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Octapharma: Consultancy, Speakers Bureau; Kedrion: Speakers Bureau. Astermark:Bayer, CSL Behring, Novo Nordisk, Octapharma, Roche, Sobi, Spark, Takeda, uniQure: Consultancy; uniQure: Research Funding. Klamroth:Bayer: Consultancy, Research Funding, Speakers Bureau; Biomarin: Consultancy, Research Funding, Speakers Bureau; CSL Behring: Research Funding, Speakers Bureau; Novo Nordisk: Consultancy, Research Funding, Speakers Bureau; Octapharma: Consultancy, Research Funding, Speakers Bureau; Pfizer: Consultancy, Research Funding, Speakers Bureau; Roche/Chugai: Consultancy, Speakers Bureau; Takeda/Shire: Consultancy, Research Funding, Speakers Bureau; Sobi: Consultancy, Speakers Bureau; Biotest: Speakers Bureau; LEO: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Lemons:uniQure: Research Funding. Visweshwar:Biogen Idec: Membership on an entity's Board of Directors or advisory committees. Escobar:Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novo Nordisk: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; National Hemophilia Foundation: Consultancy, Membership on an entity's Board of Directors or advisory committees; Biomarin, Genetech/Roche, CSL Behring, Kedrion, Magellan Healthcare: Honoraria. Gomez:Global Blood Therapeutics: Speakers Bureau. Kruse-Jarres:CSL Behring, Genentech, Inc., Spark: Research Funding; Biomarin, Chugai Pharmaceutical Co., CSL Behring, CRISPR Therapeutics, Genentech, Inc.: Honoraria; F. Hoffmann-La Roche Ltd: Speakers Bureau; Biomarin, Chugai Pharmaceutical Co., CSL Behring, CRISPR Therapeutics, Genentech, Inc.: Consultancy. Kotowski:uniQure: Research Funding. Quon:Orthopaedic Institute for Children: Current Employment; Bayer: Honoraria; Biomarin: Honoraria, Speakers Bureau; Bioverativ/Sanofi: Honoraria, Speakers Bureau; Genentech, Inc./F. Hoffmann-La Roche Ltd: Honoraria, Speakers Bureau; Novo Nordisk: Honoraria, Speakers Bureau; Octapharma: Honoraria; Shire/Takeda: Speakers Bureau. Wang:Bayer: Honoraria; Takeda: Honoraria; Genentech: Honoraria; Biomarin: Honoraria; CSL Behring: Honoraria; Bioverativ Inc: Honoraria; Catalyst Biologics: Consultancy; NovoNordisk: Consultancy; Hema biologics / LFB: Consultancy. Wheeler:Takeda: Membership on an entity's Board of Directors or advisory committees; uniQure: Membership on an entity's Board of Directors or advisory committees; Biomarin: Membership on an entity's Board of Directors or advisory committees; Novo Nordisk: Membership on an entity's Board of Directors or advisory committees. Sawyer:uniQure: Current Employment, Current equity holder in publicly-traded company. Verweij:uniQure: Current Employment. Colletta:uniQure: Current Employment. Bajma:uniQure: Current Employment. Gut:uniQure: Current Employment. Miesbach:Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Biomarin: Consultancy, Membership on an entity's Board of Directors or advisory committees; Freeline: Consultancy, Membership on an entity's Board of Directors or advisory committees; LFB: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Octapharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novo Nordisk: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Consultancy; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; uniQure: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Biotest: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding. OffLabel Disclosure: Etranacogene dezaparvovec is an investigational gene therapy

Background: Gene therapy aims to provide long-term therapeutic benefit from a single administration. AMT-060 is an adeno-associated virus serotype 5 (AAV5) vector with a codon-optimized wildtype human factor IX (FIX) gene and liver-specific promoter. AMT-060 is being evaluated in an ongoing study of 10 participants with severe/moderate-severe hemophilia B (Phase 1/2 study, NCT02396342) over 5 years. Aim: To describe efficacy and safety outcomes from an analysis at up to 5-years post-AMT-060. Methods: Adult males with FIX activity ≤2% and a severe bleeding phenotype received a single intravenous infusion of AMT-060 (5x1012 gc/kg, Cohort 1, n=5) or (2×1013 gc/kg, Cohort 2, n=5). Assessments included FIX activity, FIX replacement use, annualized bleeding rate (ABR), treatment-related adverse events (TRAE), immunological and inflammatory biomarkers up to 5 years (Cohort 1) and 4.5 years (Cohort 2). Results: As of November 2019, for Cohort 1 the mean FIX activity (at 4.0 years) was 5.1% as compared to 4.4% in the first year, 6.8% in the second year, 7.3% in the third year and 7.0% in the fourth year. Mean FIX activity for Cohort 2 was 7.5% as compared to 7.1% in the first year, 8.4% in the second year 7.9% in the third year, and 7.4% in the fourth year. Eight of 9 participants using prophylaxis at baseline were able to discontinue use. During the last 12, and 6 months of observation respectively, the mean annualized bleed rate (ABR) was 3.3. for Cohort 1 and 0.0 for Cohort 2. These represent, respectively, a reduction in mean ABR to the year prior to treatment of 77% and 100% for Cohort 1 and Cohort 2. During this same period the consumption of FIX replacement therapy declined 90% and 100% relative to pre-treatment, respectively for Cohort 1 and Cohort 2. No participants developed FIX inhibitors or signs of sustained AAV5 capsid-specific T-cell activation. As previously reported, TRAE were mainly reported in the first 3.5 months after treatment, including three participants who experienced transient mild elevations in alanine aminotransferase. One additional TRAE (joint swelling post-exercise) was observed during the last 12 months of observation post-treatment. Updated data, up to 5-years of observation, will be presented for the first time. Conclusions: Long-term stable endogenous FIX activity and reductions in ABR and FIX replacement use were sustained over multiple years following a single treatment with AMT-060. There were no additional safety concerns with longer term follow-up. This data supports the ongoing Phase 3 study of the enhanced construct etranacogene dezaparvovec (AMT-061), which encodes the highly active Padua FIX variant. Disclosures Meijer: Bayer: Research Funding; Sanquin: Research Funding; Pfizer: Research Funding; Bayer: Speakers Bureau; Sanquin: Speakers Bureau; Boehringer Ingelheim: Speakers Bureau; BMS: Speakers Bureau; Aspen: Speakers Bureau; Uniqure: Consultancy. Kampmann:Uniqure: Speakers Bureau; Shire Pharmaceuticals: Speakers Bureau. Klamroth:CSL Behring: Research Funding, Speakers Bureau; Novo Nordisk: Consultancy, Research Funding, Speakers Bureau; Octapharma: Consultancy, Research Funding, Speakers Bureau; Pfizer: Consultancy, Research Funding, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Takeda/Shire: Consultancy, Research Funding, Speakers Bureau; Sobi: Consultancy, Speakers Bureau; Biotest: Speakers Bureau; Grifols: Speakers Bureau; Biomarin: Consultancy, Research Funding, Speakers Bureau; Bayer: Consultancy, Research Funding, Speakers Bureau. Castaman:Novo Nordisk: Honoraria, Speakers Bureau; Roche: Consultancy, Honoraria, Speakers Bureau; Pfizer: Honoraria, Research Funding; Ablynx: Honoraria; Alexion: Honoraria; Bayer: Honoraria; CSL Behring: Honoraria, Research Funding; Kedrion: Speakers Bureau; Sobi: Honoraria, Research Funding, Speakers Bureau; Uniqure: Honoraria, Membership on an entity's Board of Directors or advisory committees; Werfen: Speakers Bureau; Baxalta/Shire: Honoraria. Bönig:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genzyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Healthineers: Current equity holder in publicly-traded company; Sandor-Hexal: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Polyphor: Research Funding; Miltenyi: Honoraria, Research Funding; Erydel: Research Funding; Chugai: Honoraria, Research Funding; Bayer: Research Funding; Terumo BCT: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kiadis: Honoraria; Uniqure: Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Stage: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Fresenius: Honoraria; medac: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Sawyer:uniQure: Current Employment. Miesbach:UniQure: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; BioMarin Pharmaceutical Inc: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bayer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. OffLabel Disclosure: AMT-060 = AAV5 vector gene therapy in subjects with moderate to severe hemophilia B

Introduction The treatment paradigm for people with severe hemophilia B in the US typically involves prophylaxis with factor IX (FIX) replacement therapy, the primary aim of which is to provide sufficient FIX levels to reduce the frequency of bleeding events. The clinical benefits of FIX prophylaxis are well understood, however the cost of FIX products as well as costs associated with healthcare resource utilization present a significant burden to the healthcare system. Substantive costs may also accrue in patients who continue to bleed while on prophylaxis, due to the impact on both short and long-term joint-related outcomes. In the absence of existing data in the US, the 'Cost of Hemophilia Across the USA: a Socioeconomic Survey' (CHESS US) study was conducted to establish a population-based estimate of the real-world US healthcare system burden associated with severe hemophilia. Using data drawn from the CHESS US study, this analysis examines the real-world healthcare system costs and clinical outcomes of people with severe hemophilia B on FIX prophylaxis. Methods CHESS US, a retrospective, cross-sectional dataset of adults with severe hemophilia in the USA, gathered information on patient cost via a patient record form. Data on the following parameters are included in this analysis: FIX consumption, annualized bleeding rate (ABR), the presence of one or more chronically damaged joints ("problem joint"), as well as costs associated with annual (prophylactic) factor consumption and hospitalizations (i.e., number of admissions, number of day cases, total inpatient days, and total intensive care unit [ICU] days). All variables report retrospective data of the 12 months prior to enrolment in the study. Results are presented as mean (± standard deviation) or N (%). Results In total, 132 of 576 patients profiled in the CHESS US study had severe hemophilia B. Among them, 77 patients were on FIX prophylaxis, of whom 44 patients reported FIX dosing regimen and were included in the current analyses. Among them, 20 patients were treated with conventional FIX and 24 patients with extended half-life (EHL) FIX products. The cohort has a mean age of 27.64 (± 11.05) and mean weight (kg) of 75.71 (± 13.41). In the last 12 months, the mean number of international units (IU) prescribed for FIX prophylaxis across the full cohort was 257,216 IU (± 213,591), with an associated annual cost of $610,966 (± $495,869). Among patients treated with conventional FIX, mean prescribed FIX was 287,141 IU (± 264,906) at an annual cost of $397,491 (± $359,788), while patients treated with EHL FIX reported a mean prescribed FIX of 232,278 IU (± 160,914) at an annual cost of $788,861 (± $529,258). The cohort reported a mean ABR of 1.73 (± 1.39); 8 (18%) were reported to have a target joint meeting the International Society on Thrombosis and Haemostasis (ISTH) definition; and 11% were reported to have had at least one chronically damaged joint (i.e., problem joint). Healthcare resource utilization associated with bleed events were reported as follows: hospital admissions days [0.18 (± 0.62)]; inpatient days [0.34 (± 1.22)]; and ICU days [0.23 (± 0.86)]. The direct medical cost to the healthcare system was $2,885 (± $7,857; excluding FIX cost) and $614,886 (± $498,839; including FIX cost). Discussion Data from the CHESS US study showed substantial costs and resource utilization among patients with severe hemophilia B receiving FIX prophylaxis, of which the cost of FIX replacement therapy constituted most of the total cost to healthcare system. Although the ABR observed in the analysis population was low, bleed-related hospitalizations comprised a significant non-drug cost to the healthcare system. A proportion of patients also still experienced joint arthropathy. Such substantial clinical and economic burden highlights that unmet needs remain in patients with severe hemophilia B on FIX prophylaxis in the US. Disclosures Noone: HCD Economics: Employment. Pedra:HCD Economics: Employment. Asghar:HCD Economics: Employment. O'Hara:HCD Economics: Employment, Equity Ownership. Sawyer:uniQure Inc.: Employment. Li:uniQure Inc.: Employment.

Background: The aim of gene therapy is to provide long-term therapeutic effect from a single administration, yet information on response durability is currently limited. AMT-060 is an adeno-associated virus serotype 5 (AAV5) vector with a codon-optimized wildtype human factor IX (FIX) gene and liver-specific promoter. AMT-060 is being analyzed in an ongoing study of 10 participants with severe/moderate-severe hemophilia B (Phase 1/2 study, NCT02396342). Aim: To describe efficacy and safety outcomes from a planned interim analysis at up to 4-years post-AMT-060. Methods: Adult males with FIX activity ≤2% and a severe bleeding phenotype received a single intravenous infusion of AMT-060 (5x1012gc/kg, Cohort 1, n=5) or (2×1013 gc/kg, Cohort 2, n=5). Assessments included FIX activity, FIX replacement use, annualized bleeding rate (ABR), treatment-related adverse events (TRAE), immunological and inflammatory biomarkers up to 4 years (Cohort 1) and 3.5 years (Cohort 2). Results: As of 8 May 2019, for Cohort 1 the mean yearly FIX activity (annualized to 4 years) was 6.0 as compared to 4.4% in the first year, 6.8% in the second year and 7.3% in the third year. Mean yearly FIX activity for Cohort 2 at 3 years was 7.9% as compared to 7.1% in the first year and 8.4% in the second year. Factor IX activity for each patient over the length of follow up is shown in Figure 1. Eight of 9 participants using prophylaxis at baseline were able to discontinue use. During the last 12 months of observation, the mean annualized bleed rate (ABR) was 1.7 for Cohort 1 and 0.7 for Cohort 2. Respectively, these represent a reduction in mean ABR to the year prior to treatment of 88% and 83%. During this same period the consumption of FIX replacement therapy declined 93% and 96% relative to pre-treatment respectively for Cohort 1 and Cohort 2. No participants developed FIX inhibitors or signs of sustained AAV5 capsid-specific T-cell activation. TRAE were mainly reported in the first 3.5-months after treatment, including three participants who experienced transient mild elevations in alanine aminotransferase as previously described. One new TRAE (joint swelling post-exercise) was observed during the last 12 months of observation post-treatment. Updated data, up to 4-years of observation, will be presented for the first time. Conclusions: Long-term stable endogenous FIX activity and reductions in ABR and FIX replacement use were observed following a single treatment with AMT-060. There were no additional safety concerns with longer term follow-up. These findings support the ongoing Phase III study of the enhanced construct, AMT-061, which encodes the highly active Padua FIX variant. Figure 1 Disclosures Miesbach: Bayer, BioMarin, CSL Behring, Chugai, Freeline, Novo Nordisk, Octapharma, Pfizer, Roche, Takeda/Shire, UniQure: Consultancy; Bayer, Novo Nordisk, Octapharma, Pfizer, Takeda/Shire: Research Funding; Bayer, Chugai, Novo Nordisk, Octapharma, Pfizer, Takeda/Shire, UniQure: Speakers Bureau. Meijer:Pfizer, Sanquin, Uniqure: Research Funding; Uniqure, BMS, Aspen, Boehringer Ingelheim, Sanquin, Bayer: Consultancy, Honoraria; Sanquin: Research Funding; Bayer: Research Funding. Coppens:Pfizer: Honoraria; Portola Pharmaceuticals, Inc: Honoraria; Daiichi Sankyo: Honoraria, Research Funding; Uniqure: Research Funding; Boehringer Ingelheim: Research Funding; Sanquin Blood Supply: Research Funding; Bayer: Honoraria, Research Funding; CSL Behring: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria. Kampmann:Uniqure BV: Research Funding. Klamroth:Bayer, Biomarin, CSL Behring, Novo Nordisk, Octapharma, Pfizer, Roche, SOBI, Takeda: Consultancy; Bayer, Novo Nordisk, SOBI: Research Funding. Schutgens:Baxalta Shire, Novo Nordisk, Bayer, CSL Behring, Pfizer, UniQure BV: Research Funding. Castaman:Bayer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novo Nordisk: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sobi: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; CSL Behring: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Takeda (SHIRE): Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kedrion: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Werfen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Research Funding; Uniqure: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Seifried:Medac: Other: BSD owns IP and is contract manufacturer; Uniqure BV: Research Funding. Schwaeble:Uniqure BV: Research Funding. Bönig:Celgene, Novartis, Sandoz Hexal: Consultancy; Kiadis Pharma: Other: Contract manufacturing of ATIR101; Sandoz Hexal, Uniqure: Research Funding; Miletenyi: Speakers Bureau. Sawyer:Uniqure BV: Employment. Leebeek:CSL Behring: Research Funding; UniQure: Consultancy; Shire/Takeda: Research Funding; Novo Nordisk: Consultancy; Sobi: Other: Travel grant; Shire/Takeda: Consultancy.

Introduction Hemophilia is an inherited disorder that causes a deficiency of a blood clotting factor resulting in a lifelong bleeding diathesis. People with hemophilia (PWH) may experience significant morbidity including potentially life-threatening hemorrhages and accumulation of joint damage and require burdensome and costly chronic treatment with factor replacement therapies. Gene therapies aimed at providing endogenous production of the missing clotting factor have the potential to yield significant health benefits for PWH. Economic evaluation is an important component for the commissioning and funding of new treatments like gene therapies. In economic evaluation, quality-of-life (QoL) is measured using health state utility valuations (HSUV). However, people with inherited and long-term health conditions may adapt to their given health state and adjust their expectations, therefore biasing the estimates of QoL/HSUV (i.e., disease state adaptation (DSA) or "disability paradox"; Albrecht and Devlieger, 1999). Here, we describe the first stages of research to evaluate DSA experienced by PWH. Methods To facilitate the selection of research methodology, a systematic litearure review (SLR) was performed to examine existing studies on QoL/HSUVs for PWH. A SLR was conducted to identify full-text studies by searching electronic databases (e.g. MEDLINE, Web of Science, Cochrane Library). Studies were included in the review using predefined inclusion/exclusion criteria for population, study type, language (English). Additionally, a manual search (last three years) for conferences abstracts was performed to capture the most up-to-date research. Findings from the SLR informed the conceptualisation of a study framework. The proposed research approach was then discussed with an expert panel consisting of clinicians, patient advocacy representatives, and Health Technology Assessment (HTA) specialists. Results The SLR identified 32 studies reporting HSUVs in hemophilia. The studies identified applied a mix of direct and indirect HSUV elicitation techniques. Two studies applied direct time trade-off methodology and the remaining 30 studies adopted indirect valuation methodologies. Utility values were found to vary by disease severity, musculoskeletal damage, bleed frequency, inhibitors, hemophilia subtype, treatment regimen, and adherence. Interestingly, HSUVs derived from valuations from the general public were found to be valued lower than those derived from PWH for the same health states. For example, in Carlsson et al. (2017), general public participants consistently rated significantly lower HSUVs for hemophilia disease states compared to PWH (range: 0.54-0.60 vs. 0.67-0.73), suggesting DSA might exist for PWH. Based on SLR findings, an expert panel discussed the feasibility and acceptability of an approach for conducting a preference elicitation study to directly evaluate DSA in PWH. Preference elicitation is an established research framework that is widely used in health economics. A comparative preference elicitation study was proposed to describe and quantify DSA by comparing responses from PWH, caregivers of PWH, and the general public. Conclusion Based on the SLR and expert panel inputs from clinicians, patients and HTA experts, an agreement was achieved about the research methodology for a new study directly assessing DSA experienced by PWH. Experts agreed that a comparative preference elicitation approach among PWH, caregivers of PWH, and the general public was fit-for-purpose for this research. The impact of DSA on QoL/HSUV should be characterized within economic evaluations of novel treatments with transformative impact on patients' lives, such as gene therapies. Disclosures Martin: HCD Economics: Employment. Mulhern:HCD Economics: Consultancy. Shaikh:HCD Economics: Employment. Asghar:HCD Economics: Employment. O'Hara:HCD Economics: Employment, Equity Ownership. Pedra:HCD Economics: Employment. Sawyer:uniQure Inc.: Employment. Li:uniQure Inc.: Employment.

Introduction Current adeno-associated viral (AAV) vector-based gene therapy strategies for hemophilia rely on systemic administration of the vector. Durable expression of the transgene over the span of years has been reported from several trials, yet information on the clearance of vector material from bodily fluids is still limited and monitoring of "shedding" is required during trials despite lack of evidence of environmental or transmission risk. Here, we examined the magnitude and duration of the presence of vector DNA in participants from a Phase I/II study of an AAV5-hFIX wildtype construct (AMT-060; NCT02396342) and from a Phase IIb study utilizing the enhanced version, AAV5-hFIX Padua (AMT-061; NCT03489291). Methods Adult male participants with severe or moderately severe hemophilia B received a single intravenous infusion of either AMT-060 at 5x1012 genome copies(gc)/kg (low dose) or 2×1013 gc/kg (high dose), or AMT-061 at 2x1013gc/kg in one of two ongoing trials. Assessments in both trials included efficacy and safety outcomes as well as vector shedding in whole blood and semen. Vector shedding was also measured in nasal secretions, feces, urine, and saliva in participants receiving AMT-060. Vector shedding was analyzed using a validated quantitative real time polymerase chain reaction (qPCR) based assay measuring presence of vector DNA in the bodily fluids. Vector clearance was reached when vector DNA was either zero or below the limit of detection (LOD) for three consecutive measurements. The range in time to the first and the third consecutive negative measurement for each dose group are provided. Results Treatment with AMT-060 resulted in sustained improvement in FIX activity for up to 3.5 years [Mean FIX activity was 5.1% (low dose group at 3.5 years) and 7.5% (high dose group at 3 years)] and treatment with AMT-061 resulted in mean FIX activity of 45% over 36 weeks. AMT-060 and AMT-061 reduced the mean number of annualized bleeds by between 82% and 100% respectively. AMT-060 reduced the requirement for exogenous FIX administration by 86% and was abrogated with AMT-061. Both AAV5-hFIX and AAV5-hFIX Padua were safe and well tolerated and no unexpected TRAEs have been observed with longer-term follow up. Table 1 describes the time in weeks to the first and last of three consecutive measures of vector DNA of either zero or Conclusions Post-AMT-060 treatment, vector DNA was undetectable in all participants in the high dose group by 10 months and considered cleared by 16 months in all bodily fluids except blood. AMT-060 was cleared from the blood in 100% of participants in the low dose group at 3 years and 80% of participants in the high dose group by 2.5 years. As expected, AMT-061 vector DNA was detectable at 36 weeks in blood and in the semen of 1 of 3 participants, although clearance had not yet been established in the remaining participants. The presence of vector DNA in bodily fluids assessed was not associated with any adverse safety or efficacy findings. Disclosures Sawyer: Uniqure BV: Employment. Gielen:uniQure Biopharma: Employment. Twisk:uniQure Biopharma: Employment. Long:Uniqure BV: Employment. Gut:Uniqure BV: Employment.

Gene therapy for severe hemophilia is on the cusp of entering clinical practice. However, there is limited clinical experience in this area given that gene transfer is a relatively recent technology. Therefore, this clinical perspective article will review the evidence supporting gene therapy in this field, examine ways to open a dialogue about gene therapy with patients in the clinic setting, and present a case of a participant in a recent clinical trial of gene therapy for hemophilia. Clinical trials in hemophilia using adeno-associated virus (AAV) vectors to transfer functional factor IX (FIX) have reported increases in FIX activity to functional levels, reduced bleed frequency, and a lessening or abrogation of the need for costly FIX replacement. The safety profile of AAV-mediated gene therapy also appears positive, with manageable, asymptomatic increases in liver enzymes being the most commonly described adverse event. Examining a clinical case in hemophilia B more closely, gene transfer decreased annualized bleeds from six (unknown or spontaneous) bleeds before treatment to three (spontaneous) bleeds after treatment alongside a 55% reduction in FIX replacement. The participant experienced an increase in traumatic bleeds after treatment, which appears to reflect increased physical activity and early prophylaxis discontinuation. After the gene transfer, the participant considered his hemophilia to be "cured," which emphasizes the need to manage patient expectations, particularly regarding activity levels and bleed risk in the immediate post-treatment period. Gene therapy for hemophilia has the potential to transform the lives of affected individuals and is likely to create a new class of hemophilia patient who has shifted from a severe to a mild phenotype. Despite having a mild phenotype, these individuals may retain a legacy of increased bleed risk and joint damage from their years with severe hemophilia and will need different clinical management compared to a more typical individual with mild hemophilia.

Background: Hemophilia B (HB) is a rare disease caused by congenital Factor IX (FIX) deficiency. HB requires life-long management to prevent or manage bleeding and associated morbidity. Although HB affects only a small portion of the population, it is associated with high overall cost and imposes a significant financial burden on individuals, payers, and society in general. Due to variation in patient clinical characteristics and treatment choice, cost and healthcare resource utilization associated with disease management can vary significantly from patient to patient. Aims: To review published direct costs and healthcare resource utilization associated with the management of HB in the US. Methods: A systematic literature review was conducted by searching electronic databases (e.g. MEDLINE, Tufts CEA registry) to identify full-text studies (March 2009–March 2019). Additionally, a manual search for abstracts from relevant conferences was performed (from 2016). Studies were included in the review using pre-defined inclusion/exclusion criteria for population, study type, language (English), and location (US). Publications consisting of budget impact analysis, cost, burden of disease, healthcare resource utilization, and economics evaluations were included. Results: Of 693 titles and abstracts screened, a total of 17 studies evaluating cost and resource utilization in patients with HB in the US were included. Data sources for these studies included: medical records (n = 5), insurance claims databases (n = 10), and surveys (n = 2). Reported cost and resource use varied across studies depending on severity of the disease, treatment regimen, and product type: extended (EHL) or standard half-life (SHL). The cost of FIX replacement therapy constitutes the majority of costs in HB management. Among patients with severe or moderate HB, reported mean annual cost of FIX ranged from $187,070 to $925,864 with an average of $560,801. Annual cost of EHLs could exceed more than twice the cost of SHLs. For example, mean annual cost of EHL FIX was $921,291 vs $478,096 for SHL FIX. Rates of healthcare resource utilization were also substantial for patients with HB and include hospitalizations, emergency room visits, and physician visits. Conclusions: This systematic literature review found significant economic burden associated with HB in the US. The substantial costs and health resources utilized by patients highlight unmet needs remaining in HB.

Alcohol potentiates GABAergic neurotransmission via action at the GABAA receptor. α1 subunit-containing GABAA receptors have been implicated as mediators, in part, of the behavioral and abuse-related effects of alcohol in rodents.We systematically investigated the effects of 1 α1-preferring benzodiazepine agonist, zolpidem, and 2 antagonists, β-carboline-3-carboxylate-tert-butyl ester (βCCT) and 3-propoxy-β-carboline hydrochloride (3-PBC), on oral self-administration of alcohol (2% w/v) or sucrose solution and observable behavior in rhesus macaques. We compared these effects to those of the nonselective benzodiazepine agonist triazolam, antagonist flumazenil, and inverse agonist β-carboline carboxylate (βCCE).Alcohol and sucrose solutions maintained reliable baseline drinking behavior across the study. The α1-preferring compounds did not affect intake, number of sipper extensions, or blood alcohol levels (BALs) at any of the doses tested. Zolpidem, βCCT, and 3-PBC increased latency to first sipper extension in animals self-administering alcohol, but not sucrose, solution. Triazolam exerted biphasic effects on alcohol-drinking behavior, increasing intake at low doses but decreasing BAL and increasing latency at higher doses. At doses higher than those effective in alcohol-drinking animals, triazolam increased sucrose intake and latency. Flumazenil nonsystematically increased number of extensions for alcohol but decreased BAL, with no effects on sucrose drinking. βCCE decreased sipper extensions for alcohol and increased latency for first sucrose sipper extension, but full dose-effect relationships could not be determined due to seizures at higher doses.Alcohol-drinking animals appeared more sensitive to the effects of GABAergic compounds on drinking behavior. However, these results do not support a strong contribution of α1GABAA receptors to the reinforcing effects of alcohol in primates.

Introduction: AMT-060 consists of an adeno-associated virus serotype 5 (AAV5) vector containing a codon-optimized wildtype human factor IX (FIX) gene under control of a liver-specific promoter. We have previously reported on the safety and efficacy of AMT-060 gene therapy at 2 dose levels in adults with moderate-severe or severe hemophilia B with up to 1-year follow-up. Here we present longer-term follow-up data on reductions in annualized bleed rates and FIX consumption up to 2.5 years post-treatment. Methods: Multi-national, open-label, dose-escalating study in participants (pts) with FIX activity ≤2 % of normal, and a severe bleeding phenotype (NCT02396342). Pts received either 5x1012 gc/kg (Cohort 1, n=5) or 2×1013 gc/kg (Cohort 2, n=5) of AMT-060 iv. Duration of follow-up was 2.5 and 2 years in Cohort 1 and Cohort 2, respectively. Efficacy assessments include FIX activity (measured ≥10 days after use of exogenous FIX), reduction of FIX use, and annualized total bleeding rates. Bleeds were counted for each individual patient starting after discontinuation of prophylaxis post-AMT-060. For Cohort 1, exogenous FIX use and bleeds for "year 3" are presented as a calculated annualized mean using data captured between 2 and 2.5 years. Safety assessments include treatment-related adverse events, immunological and inflammatory biomarkers. Results: Nine pts with severe (FIX 5% in Cohort 1, a single bleed was reported in year 2 and no bleeds were reported to data cut-off in year 3. For the two patients with FIX activity Conclusions: Stable endogenous FIX concentrations >4% have now been observed out to 2.5 years post-treatment with AMT-060. In addition, we have observed continued reductions in annualized bleeds to near zero with the higher dose of AMT-060, and a 78-93% reduction in exogenous FIX use. The lack of additional safety concerns or treatment-related adverse events over the longer study period, including no recurring changes in ALT, support the continued development and transition of AMT-060 to AMT-061, which will use the same AAV5 vector to deliver the 2×1013 gc/kg dose with the enhanced Padua transgene, which is anticipated to increase FIX activity 6-8 fold. Disclosures Leebeek: CSL Behring: Research Funding; Uniqure: Research Funding; Baxalta/Shire: Research Funding. Meijer:BMS: Honoraria; Aspen: Honoraria; Boehringer Ingelheim: Honoraria; Pfizer: Research Funding; Sanquin: Honoraria, Research Funding; Bayer: Honoraria, Other: Travel support, Research Funding; UniQure: Research Funding. Coppens:Bayer: Honoraria, Other: Non-financial support, Research Funding; CSL Behring: Honoraria, Other: non-financial support, Research Funding; Uniqure BV: Research Funding. Kampmann:Uniqure BV: Research Funding. Klamroth:Baxalta (Shire), Bayer, CSL Behring, Novo Nordisk, Octapharma, Pfizer, Shire, and SOBI: Consultancy; Baxalta (Shire), Bayer, CSL Behring, Novo Nordisk, Octapharma, Pfizer, Shire, and SOBI: Research Funding. Schutgens:Baxalta/Shire: Research Funding; Novo Nordisk: Research Funding; Bayer: Research Funding; CSL Behring: Research Funding; Pfizer: Research Funding; Uniqure BV: Research Funding. Seifried:Medac: Other: BSD owns IP and is contract manufacturer; Uniqure BV: Research Funding. Schwaeble:UniQure BV: Research Funding. Bonig:Kiadis Pharma: Consultancy. Sawyer:Uniqure BV: Employment. Miesbach:Bayer, Shire, Biotest, pfizer, Octapharma, LFB, CSL Behring, SOBI, Biogen, BPL: Consultancy; UniQure BV: Research Funding; Novo Nordisk: Consultancy, Research Funding.

Benzodiazepines are prescribed widely but their utility is limited by unwanted side effects, including abuse potential. The mechanisms underlying the abuse-related effects of benzodiazepines are not well understood, although α1 subunit-containing GABAA receptors have been proposed to have a critical role. Here, we examine the reinforcing effects of several compounds that vary with respect to intrinsic efficacy at α2, α3, and α5 subunit-containing GABAA receptors but lack efficacy at α1 subunit-containing GABAA receptors (‘α1-sparing compounds'): MRK-623 (functional selectivity for α2/α3 subunit-containing receptors), TPA023B (functional selectivity for α2/α3/α5 subunit-containing receptors), and TP003 (functional selectivity for α3 subunit-containing receptors). The reinforcing effects of the α1-sparing compounds were compared with those of the non-selective benzodiazepine receptor partial agonist MRK-696, and non-selective benzodiazepine receptor full agonists, midazolam and lorazepam, in rhesus monkeys trained to self-administer midazolam or cocaine, under a progressive-ratio schedule of intravenous (i.v.) drug injection. The α1-sparing compounds were self-administered significantly above vehicle levels in monkeys maintained under a midazolam baseline, but not under a cocaine baseline over the dose ranges tested. Importantly, TP003 had significant reinforcing effects, albeit at lower levels of self-administration than non-selective benzodiazepine receptor agonists. Together, these results suggest that α1 subunit-containing GABAA receptors may have a role in the reinforcing effects of benzodiazepine-type compounds in monkeys with a history of stimulant self-administration, whereas α3 subunit-containing GABAA receptors may be important mediators of the reinforcing effects of benzodiazepine-type compounds in animals with a history of sedative-anxiolytic/benzodiazepine self-administration.

Previously, we showed that chronic selective serotonin reuptake inhibitor (SSRI) treatment resulted in a significant suppression of cocaine-primed reinstatement that persisted after 6 weeks of wash...

Acute SSRI (selective serotonin reuptake inhibitor) treatment has been shown to attenuate the abuse-related effects of cocaine; however, SSRIs have had limited success in clinical trials for cocaine abuse, possibly due to neurobiological changes that occur during chronic administration. In order to better understand the role of serotonin (5HT) in cocaine abuse and treatment, we examined the effects of chronic treatment with the SSRI fluoxetine at clinically relevant serum concentrations on cocaine-related neurobiology and behavior. Rhesus macaques self-administering cocaine underwent a 6-week dosing regimen with fluoxetine designed to approximate serum concentrations observed in humans. Self-administration and reinstatement were monitored throughout the treatment and washout period. In vivo microdiaylsis was used to assess changes in dopaminergic and serotonergic neurochemistry. Positron emission tomography was used to assess changes in the 5HT transporter and 2A receptor binding potential (BP). Functional output of the 5HT system was assessed using prolactin levels. Cocaine-primed reinstatement and cocaine-elicited dopamine overflow were significantly suppressed following chronic fluoxetine treatment. 5HT2A receptor BP was increased in the frontal cortex following treatment while prolactin release was blunted, suggesting desensitization of the 5HT2A receptor. These effects persisted after a 6-week washout period. Measures of pre-synaptic serotonergic function and cocaine self-administration were unaffected. These data demonstrate that acute and chronic fluoxetine treatments exert different effects on cocaine-related behavior. Furthermore, chronic fluoxetine treatment causes alterations in 5HT2A receptors in the frontal cortex that may selectively disrupt cocaine-primed reinstatement. Fluoxetine may not be useful for treatment of ongoing cocaine abuse but may be useful in relapse prevention.

Dopamine transporter (DAT) inhibitors have been developed as a promising treatment approach for cocaine dependence. However, the stimulant effects of DAT inhibitors have the potential to disrupt sleep patterns, and the influence of long-term treatment on dopamine neurochemistry is still unknown. The objectives of this study were to (1) explore the stimulant-related effects of chronic DAT inhibitor (RTI-336) treatment on motor activity and sleep-like measures in male rhesus monkeys (Macaca mulatta; n = 4) and (2) to determine the effect of drug treatment on prolactin and cortisol levels. Subjects were fitted with a collar-mounted activity monitor to evaluate their motor activity, with 4 days of baseline recording preceding 21 days of daily saline or RTI-336 (1 mg/kg/day; intramuscular) injections. Blood samples were collected immediately prior to and following chronic treatment to assess hormone levels. RTI-336 produced a significant increase in locomotor activity at the end of the daytime period compared to saline administration. During the 3-week treatment period, sleep efficiency was decreased and the fragmentation index and latency to sleep onset were significantly increased. Hormone levels were not changed throughout the study. Chronic treatment with RTI-336 has a mild but significant stimulant effect, as evidenced by the significant increase in activity during the evening period which may cause minor disruptions in sleep measures.

A consistent observation in drug abuse research is that males and females show differences in their response to drugs of abuse. In order to understand the neurobiology underlying cocaine abuse and effective treatments, it is important to consider the role of sex differences. Sex hormones have been investigated in both behavioral and molecular studies, but further evidence addressing drug abuse and dependence in both sexes would expand our knowledge of sex-differences in response to drugs of abuse. Neuroimaging is a powerful tool that can offer insight into the biological bases of these differences and meet the challenges of directly examining drug-induced changes in brain function. As such, neuroimaging has drawn much interest in recent years. Specifically, positron emission tomography (PET), single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI) technology have emerged as effective non-invasive approaches for human and animal models. Studies have revealed sex-specific changes in patterns of brain activity in response to acute cocaine injection and following prolonged cocaine use. SPECT and PET studies have demonstrated changes in the dopamine transporter but are less clear on other components of the dopaminergic system. This review highlights contributions of neuroimaging toward understanding the role of sex differences in the drug abuse field, specifically regarding cocaine, and identifies relevant questions that neuroimaging can effectively address.

Background/Aims: Fluoxetine (Prozac) is a selective serotonin reuptake inhibitor currently used to treat depression and mood disorders. It has been widely studied clinically and preclinically, yet there is limited knowledge of its pharmacokinetics in nonhuman primates. Methods: The present study characterized the pharmacokinetics of fluoxetine and its active metabolite norfluoxetine in rhesus macaques following both acute (1, 3, 5.6 and 10 mg/kg) and chronic doses (5.6 and 10 mg/kg/day) via different routes of administration (intravenous, subcutaneous, intramuscular, and oral). Blood samples were collected at multiple time points following administration and analyzed using mass spectrometry. Results: Fluoxetine had a half-life of 11–16 h and norfluoxetine had a half-life of 21–29 h. Potentially functionally significant serum concentrations of norfluoxetine were present at 24 h even after a single administration of fluoxetine. Similar to observations in humans under steady state conditions, norfluoxetine accounted for the greater percentage of active drug in the blood stream. Conclusion: A daily dose of 10 mg/kg administered orally maintained serum concentrations in the human clinical range over the course of 6 weeks. Given the long half-lives of fluoxetine and norfluoxetine observed in this study, precautions should be taken when designing preclinical studies to prevent accumulation of drug serum concentrations.