Bringing Gene Therapy Into Real World Clinical Practice

Area of Science:

• Hematology
• Gene Therapy
• Viral Vectors

Background:

• Adeno-associated virus (AAV)-based gene therapy has revolutionized hemophilia treatment by enabling direct hepatic gene transfer.
• This approach restores endogenous clotting factor expression, reducing the need for traditional prophylactic treatments.

Purpose of the Study:

• To review the current state of AAV-based gene therapy for hemophilia.
• To discuss the clinical benefits, challenges, and future directions of this therapeutic modality.

Main Methods:

• Review of clinical data and outcomes for approved AAV gene therapies (valoctocogene roxaparvovec and etranacogene dezaparvovec).
• Analysis of challenges including immunogenicity, variable expression, and long-term durability.
• Examination of necessary clinical infrastructure and monitoring guidelines.

Main Results:

• Sustained increases in Factor VIII or IX levels observed, leading to reduced bleeding episodes and improved quality of life.
• Significant challenges identified: immune-mediated hepatocellular inflammation, inter-individual variability in factor expression, and uncertain long-term efficacy.
• Established international guidelines for lifelong monitoring to detect adverse events like hepatotoxicity and malignancies.

Conclusions:

• AAV gene therapy holds transformative potential for hemophilia but faces slow real-world adoption due to scientific, operational, and reimbursement hurdles.
• Registries and harmonized monitoring are crucial for optimizing outcomes and defining long-term safety in clinical practice.