Figure 2.

Efficacy of Transgene Expression

(A) Liver, skin, and peripheral fat showed stable low-level VCN between 6 and 48 postnatal months. VCN at 6 months was higher in muscle and omentum compared with the liver at 6 months and decreased rapidly thereafter. Vector copies persisted at stable low levels in the liver and other tissues in the presence of continued growth. (B) AAV8 recipients demonstrated more efficient expression (533.9 ± 748.4% hFIX activity per vector copy versus 68.6 ± 138.4% per vector copy with AAV5, ns). Comparison of individual hepatic VCN shows a 1 to 2 log-fold decrease in 5006 compared to other AAV5 recipients, whereas VCN in 8007 was lower than that in 8006 to the same extent. (C) Males had a log-fold higher hFIX expression than did females (38.9 ± 59.6% versus 3.6 ± 3.9%, p < 0.0001) throughout the surveillance period, (D) with a non-significant trend toward higher expression efficacy (210.1 ± 436.9% versus 20.1 ± 32.5% per vector copy in females). Error bars in (A) and (C) indicate SD.