Efficacy of AAV-cFVIII vectors in vivo. Hem-A mice were injected via the portal vein with either 3 × 10¹⁰ (♦), 3 × 10¹¹ (▪), or 9 × 10¹¹ (▴) vg/mouse of both AAV-cFVIII-HC and AAV-cFVIII-LC. Mice were bled periodically via the retro-orbital plexus; plasma was harvested and analyzed by ELISA for cFVIII-LC antigen expression (A) and by Coatest for FVIII activity (B). The specific activity was calculated based on the determined activity and LC antigen levels (C). In normal cFVIII plasma, the antigen and activity levels are 200 ng/mL and 7000 mU/mL, respectively. Error bars indicate standard deviation.