ArticleClinical pharmacokinetics2025
Population Modeling of Factor IX Activity Following Administration of Fidanacogene Elaparvovec Gene Therapy in Participants with Hemophilia B.
Article in Clinical pharmacokinetics, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to 8 registered trials, which are not on this map. Cited by 3 papers.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
An Open-Label, Single-Arm, Safety and Efficacy Study of Recombinant Human Factor IX (rFIX; BeneFIX®) in Children Less Than 6 Years of Age With Severe Hemophilia B
An Open-label Safety and Efficacy Study of Recombinant Human Factor IX (rFIX; BeneFIX®) in Previously Treated Patients (PTPs) With Hemophilia B (FIX:C ≤2%)
A Double-Blind, Randomized, Crossover Evaluation of the Pharmacokinetics of Recombinant Human Factor IX (BeneFIX) and a New Formulation of BeneFIX (rFIX-R); and an Open-Label Safety and Efficacy Evaluation of rFIX-R in Previously Treated Patients With Moderate to Severe (FIX:C≤2%) Hemophilia B
A Multicenter, Open-Label Study To Compare On-Demand Treatment With 2 Prophylaxis Regimens of Recombinant Coagulation Factor IX (BeneFIX) Reformulated Drug Product (rFIX-R) In Subjects With Severe Hemophilia B
A Multicenter, Open-label Study To Compare On-demand Treatment To A Prophylaxis Regimen Of Nonacog-alfa (Benefix) In Subjects With Moderately Severe To Severe Hemophilia B (Fix:c</=2%)
Gene Therapy, Open-label, Dose-escalation Study of PF-06838435 (SPK-9001) [Adeno-associated Viral Vector With Human Factor IX Gene] in Subjects With Hemophilia B
A factor ix (fix) gene transfer, multi center evaluation of the long term safety and efficacy study of pf 06838435 and a dose escalation substudy in individuals with hemophilia b
Phase 3, Open-label, Single-arm Study to Evaluate Efficacy and Safety of FIX Gene Transfer With PF-06838435 (rAAV-Spark100-hFIX-R338L) in Adult Male Participants With Moderately Severe to Severe Hemophilia B (FIX:C ≤2%) (BeneGene-2)
Who cites it
3 citing papers in PubMed.
- Industry Perspective on Translational and Clinical Pharmacology Aspects of Viral-based Gene Therapies and Vaccines-Key Considerations and Learnings From Approved Products.The AAPS journal · 2026Review
- Review
- Intelligent design of tumor microenvironment-responsive Adeno-associated virus vectors: overcoming delivery barriers and enabling precision therapy.Medical oncology (Northwood, London, England) · 2025Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
4 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
BACKGROUND AND
objectiveFidanacogene elaparvovec (BEQVEZ™), an adeno-associated virus-based gene therapy approved for the treatment of hemophilia B, enables endogenous production of factor IX (FIX), preventing bleeding and reducing the need for FIX replacement. Nonlinear mixed-effects models are routinely used for population pharmacokinetic analyses of FIX replacement therapies but have not previously been applied to FIX activity observations from gene therapy trials. A nonlinear mixed-effects modeling approach was used to characterize FIX activity following fidanacogene elaparvovec and/or FIX replacement, identify covariates affecting FIX activity, and estimate the longer-term durability of FIX activity after a single dose of fidanacogene elaparvovec.
methodsPopulation modeling using NONMEM
resultsFIX activity was described by a compartmental model for gene and protein expression and a three-compartment model for FIX disposition. Covariates included age and body weight on gene-therapy-related parameters. Following fidanacogene elaparvovec administration, model-predicted FIX activity reached a median (90% prediction interval) peak of 13.5 (3.12-41.3) IU/dL and remained within 50% of the peak for a median of 8.67 (0.411-15.0) years. At 15 years post-infusion, median predicted FIX activity was 4.11 (1.15-17.6) IU/dL.
conclusionsModel-based estimates showed that a single dose of fidanacogene elaparvovec elicited long-lasting elevations in FIX activity, suggesting most individuals would not require prophylactic FIX replacement for at least 15 years post-infusion. CLINICALTRIALS: GOV IDENTIFIER: NCT00364182, NCT01335061, NCT00037557, NCT00093171, NCT00093210, NCT03861273, NCT03307980, NCT02484092.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.