Therapeutic levels of FVIII expression were detected in canine blood plasma after UMGD. (A) Male dogs between age 1 and 4 years weighing 14 to 20 kg were used for this study. (B) Four dogs were treated using the transcutaneous UMGD procedure with RN18 MBs under the conditions described in Figure 2 to deliver pHP-hF8-X110. Blood was collected at various time points after the procedure for up to 30 days (FLR001) or 60 days (FLR002, FLR003, and FLR004), and FVIII antigen levels in plasma were evaluated by FVIII-specific enzyme-linked immunosorbent assay (ELISA). Control plasma samples were collected from each individual dog before surgery. Data at each time point is the average of at least 2 ELISAs.