Coagulation parameters after muscle-directed AAV2-mediated FIX gene therapy in hemophilia B dogs. The ACT (A), WBCT (B), and aPTT (C) as a function of time after vector administration in hemophilia B dogs, Wilbur (♦) and Sauvignon (). The arrows indicate cyclophosphamide administration to Wilbur before and 2, 4, and 6 weeks after vector administration. The WBCT test was terminated at 60 minutes if a clot had not formed for the first 15 weeks. After 15 weeks, the WBCT test was terminated after 20 minutes if a clot had not formed.