Gene Therapy Applications in Hemophilia Management

Hemophilia is an inherited bleeding disorder caused by deficiency of coagulation factor VIII (haemophilia A) or IX (haemophilia B). Traditional management relies on regular intravenous infusions of the missing factor, yet this regimen imposes treatment burdens and remains susceptible to inhibitor development. Gene therapy offers a one-time modality by delivering a functional copy of the defective gene to the liver, the primary site of coagulation factor synthesis. Adeno-associated virus (AAV) vectors dominate the clinical landscape due to their favourable safety profile and ability to mediate long-term gene expression in hepatocytes. Early-phase trials have demonstrated sustained elevation of factor levels into or above the mild haemophilia range, resulting in marked reductions in bleed rates and prophylactic requirements. Current efforts focus on optimising vector potency, minimising immune barriers, ensuring manufacturing scalability and extending access globally. Innovations in capsid engineering, promoter selection and immunomodulation strategies aim to enhance transduction efficiency, durability and tolerability. Emerging techniques such as precision genome editing and next-generation non-viral platforms hold promise for broader application and for patients with pre-existing anti-AAV immunity. By transforming haemophilia into a potentially curative condition, gene therapy represents a paradigm shift in the management of bleeding disorders, offering durable haemostatic correction and improved quality of life.

Research from Nature Portfolio

Studies in non-human primates have revealed that following high-dose AAV administration to the liver, vector genomes initially persist as episomes and then partially integrate into hepatocyte chromosomes, leading to a stable, lower-level expression phase after an early decline. This two-phase model clarifies mechanisms underlying long-term transgene persistence and informs safety assessments. In parallel, co-administration of rapamycin-loaded nanoparticles with AAV vectors selectively suppressed anti-capsid B and T cell responses, enabling successful vector re-administration in animal models. These advances address key hurdles of expression durability and immunogenicity, guiding improved vector design and dosing regimens for repeat dosing in haemophilia gene therapy.

Gene Therapy Applications in Hemophilia Management publication trend

The graph below shows the total number of articles in gene therapy applications in hemophilia management across all publications each year (not limited to Nature Index journals).

Technical terms

Adeno-associated virus (AAV): A non-pathogenic viral vector commonly used for in vivo gene delivery to hepatocytes.

Transgene: The therapeutic gene sequence carried by the vector to restore or confer gene function.

Episomal: Extrachromosomal DNA maintained in the nucleus without integrating into the host genome.

Hepatocyte: A liver parenchymal cell responsible for coagulation factor synthesis.

Immunogenicity: The potential of a vector or transgene product to elicit an immune response.

Inhibitor: A neutralising antibody directed against infused or endogenously expressed coagulation factor.

Gene replacement therapy: A strategy to correct a genetic defect by delivering a functional gene copy.

References

1. Adeno-associated virus as a delivery vector for gene therapy of human diseases. Signal Transduction and Targeted Therapy (2024).
2. Integrated vector genomes may contribute to long-term expression in primate liver after AAV administration. Nature Biotechnology (2023).
3. Viral vector platforms within the gene therapy landscape. Signal Transduction and Targeted Therapy (2021).
4. Current Clinical Applications of In Vivo Gene Therapy with AAVs. Molecular Therapy (2020).
5. Human Immune Responses to Adeno-Associated Virus (AAV) Vectors. Frontiers in Immunology (2020).
6. Antigen-selective modulation of AAV immunogenicity with tolerogenic rapamycin nanoparticles enables successful vector re-administration. Nature Communications (2018).