Ben Samelson-Jones presented long-term safety data for Pfizer's Beqvez (fidanacogene elaparvovec), an AAV-based gene therapy for hemophilia B, at the 66th ASH Annual Meeting. The analysis, covering 60 patients over 3-6 years, showed no thrombotic complications, factor IX inhibitors, or malignancies. Adverse events were mild and unrelated to the vector, with infusion reactions absent. Challenges in gene therapy uptake include its one-time treatment nature and high cost, requiring different institutional processes and approvals.