Delivery of AAV2-cFIX via ATVRX with no IS. (A) Canine FIX antigen levels measured by ELISA. (B-C) Coagulation parameters measured by WBCT (m indicates minutes) and aPTT (s indicates seconds). (D-E) Anti-cFIX IgG1 and IgG2 subclass antibody titer measured by ELISA in J03 (D) and J62 (E). *Peak neutralizing antibody titer (1.5 BU at day 35 after ATVRX). Shaded gray areas represent range of values for hemostatically normal animals. Vertical arrows represent pooled normal plasma administrations. x axis represents time in days.