Patient-Relevant Questions on Gene Therapy for Haemophilia

BACKGROUND: Adeno-associated virus-based gene therapy has, for the first time, made durable endogenous clotting-factor production achievable from a single infusion, with products licensed in Europe for haemophilia A (2022) and haemophilia B (2023). Availability has nevertheless narrowed after the withdrawal of valoctocogene roxaparvovec and the discontinuation of fidanacogene elaparvovec, etranacogene dezaparvovec is now the only gene therapy still available.

Established efficacy, restricted availability, and remaining uncertainties together leave patients facing a decision that raises considerably more questions than conventional prophylaxis.

METHODS: The GTH Gene Therapy Working Group, together with the German-speaking patient organisations (the German DHG and Interessengemeinschaft Hämophiler, the Austrian ÖHG, and the Swiss Haemophilia Society), collected and consolidated more than 100 questions submitted by affected individuals. These were grouped into thematic categories - fundamentals, efficacy, safety, access, the treatment pathway, and quality of life - and answered on the basis of current evidence.

RESULTS: More than 100 questions were consolidated into three thematic blocks - fundamentals, efficacy and safety; access, procedure and everyday life; research and further development - and answered in a form that can be used directly in shared decision-making. The questions raised most often concerned the durability of factor expression, transaminase elevations and vector-directed immune responses, eligibility and antibody screening, the intensity of follow-up, and the consequences of a shrinking product landscape for individual patients. Each answer distinguishes what is established from what remains uncertain and identifies the points that require individual discussion with the treating centre.

CONCLUSION: The catalogue provides clinicians with a practical tool for informed-consent discussions and for shared decision-making. Because the treatment landscape continues to evolve, patient information will need to be kept continuously up to date.