Efficacy and Safety in 15 Hemophilia B Patients Treated with the AAV Gene Therapy Vector Fidanacogene Elaparvovec and Followed for at Least 1 Year
Bibliographic record
Abstract
Background: Adeno-Associated Virus (AAV) based liver transduction has emerged as a potentially viable gene therapy approach for the treatment of hemophilia patients. Fidanacogene elaparvovec (previously SPK-9001) is a hepatotropic bioengineered AAV based vector that delivers a high activity factor IX (FIX) transgene driven by a liver specific promoter. The Phase 1/2a development consists of a dosing study where patients are followed for 52 weeks post vector infusion followed by a long-term follow-up study for an additional 5 years. Data on the first 10 patients were previously published and demonstrated safe and sustained expression of a high activity FIX protein with an associated decreased requirement for exogenous factor administration and markedly reduced annualized bleeding rate. Here we present data on 15 patients infused with fidanacogene elaparvovec with ≥ 1 year of follow-up, which represents the largest cohort of Hemophilia B (HB) patients treated with the same vector at the same dose. Methods: Fifteen (15) adult HB patients were infused with 5 x 1011 vg/kg of fidanacogene elaparvovec and followed for at least 1 year as part of the Phase 1/2a dosing study. FIX activity (FIX:C) levels were measured using a one-stage assay. Endpoints include: Safety and tolerability, steady-state activity calculated as the geometric mean of all observed FIX:C activity levels from week 12 through week 52; annualized bleeding rate (ABR) prior to and 52 weeks after vector infusion; T cell response to fidanacogene elaparvovec capsid and transgene monitored post-infusion using an interferon-γ enzyme-linked immunospot (ELISpot) assay. Results: Three of fifteen patients were treated with corticosteroids for elevations in hepatic transaminases of which 2 were positive for capsid reactive T cells by interferon-γ ELISpot. There were otherwise no treatment related adverse events. The mean post-infusion steady-state FIX:C was 22.9%±9.9% at 1 year post vector infusion as measured in a central laboratory by one-stage assay utilizing Actin-FSL. Mean ABR during the first 52 weeks following fidanacogene elaparvovec infusion was 0.4±1.1 compared to 8.9±14.0 in the 52 weeks preceding infusion (p<0.001). Twelve (12) out of 15 patients reported zero bleeds in the 52 weeks post-vector infusion. Five of 15 subjects infused factor for a total of 20 infusions. Additional follow-up data will be presented for all patients enrolled in the long-term follow-up study. Conclusions: Fidanacogene elaparvovec was well tolerated in 15 patients with no serious adverse events. Data for all patients at 52 weeks post-infusion demonstrated a marked reduction in bleeding frequency and exogenous FIX use. All hepatic transaminase elevations responded to treatment with corticosteroids. Collectively, to date, this represents the largest cohort of HB patients treated with the same AAV based gene therapy and at the lowest dose. Treatment has been efficacious for all patients with manageable immune responses when present. These data support progression to a pivotal Phase 3 study at the dose evaluated. Disclosures George: University of Pennyslvania: Employment; Avrobio: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy. Sullivan:Octapharma: Consultancy, Other: Advisory Board. Rasko:bluebird bio: Honoraria; Celgene: Honoraria; Novartis: Honoraria; FSHD Global Research Foundation: Membership on an entity's Board of Directors or advisory committees; Rarecyte: Consultancy, Equity Ownership; Gene Technology Technical Advisory, Australian Government: Other: Advisory committee; GSK: Honoraria; Takeda: Honoraria; Cynata: Honoraria; Genea: Equity Ownership; Cure The Future Foundation: Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria; Pfizer: Honoraria; Spark: Honoraria; Imago: Consultancy; Advisory Committee on Biologics, Australian Government: Other: Advisory Committee; NHMRC Mitochondrial Donation Expert Working Committee: Other: Advisory Committee; Australian Cancer Research Scientific Advisory Board: Membership on an entity's Board of Directors or advisory committees. Giermasz:Genentech/Roche: Consultancy, Other: Research, Speakers Bureau; uniQure: Consultancy, Other: Research; Bioverativ/Sanofi: Consultancy, Speakers Bureau; BioMarin: Consultancy, Other: Research; Sangamo: Other: Research. Samelson-Jones:The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania: Employment. Ducore:Bayer: Consultancy, Honoraria, Other: speaker (not bureau); Spark Therapeutics: Research Funding; Shire: Consultancy, Honoraria; Octapharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; HEMA Biologics: Consultancy, Honoraria; BioMarin: Research Funding; Bioverativ: Research Funding. Teitel:BioMarin: Consultancy; Bayer: Consultancy, Research Funding; Shire: Consultancy; Pfizer: Consultancy, Research Funding; Novo Nordisk: Consultancy; Octapharma: Consultancy; CSL Behring: Consultancy. McGuinn:Biogen: Research Funding; Roche/Genetech: Research Funding; Spark: Research Funding; Shire/Baxalta: Consultancy, Research Funding. Wright:Solid Biosciences: Consultancy; Yposkesi: Other: Senior Advisor, SAB; LogicBio Therapeutics: Other: Member, SAB; Memorial Sloan Kettering Cancer Center: Consultancy; Agilis Biotherapeutics: Consultancy; Axovant Sciences: Other: Chief Technology Officer, Gene Therapies; Akous Therapeutics: Consultancy; National Institutes of Health: Consultancy; Leland Stanford Junior University: Consultancy; Wright Biologics: Other; Sanofi Genzyme: Consultancy; Spark Therapeutics: Consultancy, Other: co-founder, Chief Technology Advisor/Officer, Member, SAB; Adrenas Therapeutics: Other: Member, SAB; Ambys Medicines: Consultancy; CEVEC Pharmaceuticl: Other: Member, SAB. Anguela:Spark Therapeutics: Employment, Equity Ownership, Patents & Royalties. High:Spark Therapeutics: Employment, Equity Ownership, Patents & Royalties. Rybin:Pfizer: Employment. Murphy:Pfizer Inc.: Employment. Rupon:Pfizer: Employment.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".