Therapeutic levels of circulating hFIX achieved in AAV8-naive mice and rhesus monkeys. Levels of hFIX were determined by ELISA and presented on the left y-axis, and the corresponding percentage of normal FIX levels (5000 ng/mL) is presented on the right y-axis. (A) AAV8-naive monkeys received 5 × 10¹² vg/kg AAV8-hFIX vectors via direct intrahepatic artery injection. (B) C57Bl/6 mice received 1 × 10¹¹ vg/mouse (ie, 4 × 10¹² vg/kg) AAV8-or AAV2-hFIX by direct intraportal vein injection. Results presented here are means ± SEM from all data collected from 3 independent experiments comparing 3 lots of AAV8 and 2 lots of AAV2 vectors. Each time point consists of a minimum of 3 mice or a maximum of 21 mice.