<br>        Inclusion Criteria:<br><br>          -  Male subjects, younger than 12 years old.<br><br>          -  Severe hemophilia B (Factor IX [FIX] activity of = 2%).<br><br>          -  Body weight = 10 kg.<br><br>          -  Subjects who have received FIX products (plasma-derived and/or recombinant FIX) for ><br>             150 exposure days (EDs) (6 to < 12 years), and > 50 EDs (< 6 years).<br><br>          -  No history of FIX inhibitor formation, no detectable inhibitors at Screening and no<br>             family history of inhibitors against FIX.<br><br>          -  Written informed consent for study participation.<br><br>        Exclusion Criteria:<br><br>          -  Known hypersensitivity to any FIX product or hamster protein.<br><br>          -  Known congenital or acquired coagulation disorder other than congenital FIX<br>             deficiency.<br><br>          -  Kidney or liver disease.<br><br>          -  Recent life-threatening bleeding episode.<br>      ;<br>        Inclusion Criteria:<br><br>          -  Male subjects, younger than 12 years old.<br><br>          -  Severe hemophilia B (Factor IX [FIX] activity of = 2%).<br><br>          -  Body weight = 10 kg.<br><br>          -  Subjects who have received FIX products (plasma-derived and/or recombinant FIX) for ><br>             150 exposure days (EDs) (6 to < 12 years), and > 50 EDs (< 6 years).<br><br>          -  No history of FIX inhibitor formation, no detectable inhibitors at Screening and no<br>             family history of inhibitors against FIX.<br><br>          -  Written informed consent for study participation.<br><br>        Exclusion Criteria:<br><br>          -  Known hypersensitivity to any FIX product or hamster protein.<br><br>          -  Known congenital or acquired coagulation disorder other than congenital FIX<br>             deficiency.<br><br>          -  Kidney or liver disease.<br><br>          -  Recent life-threatening bleeding episode.<br>      ;<br>        Inclusion Criteria:<br><br>          -  Male subjects, younger than 12 years old.<br><br>          -  Severe hemophilia B (Factor IX [FIX] activity of = 2%).<br><br>          -  Body weight = 10 kg.<br><br>          -  Subjects who have received FIX products (plasma-derived and/or recombinant FIX) for ><br>             150 exposure days (EDs) (6 to < 12 years), and > 50 EDs (< 6 years).<br><br>          -  No history of FIX inhibitor formation, no detectable inhibitors at Screening and no<br>             family history of inhibitors against FIX.<br><br>          -  Written informed consent for study participation.<br><br>        Exclusion Criteria:<br><br>          -  Known hypersensitivity to any FIX product or hamster protein.<br><br>          -  Known congenital or acquired coagulation disorder other than congenital FIX<br>             deficiency.<br><br>          -  Kidney or liver disease.<br><br>          -  Recent life-threatening bleeding episode.<br>      ;<br>        Inclusion Criteria:<br><br>          -  Male subjects, younger than 12 years old.<br><br>          -  Severe hemophilia B (Factor IX [FIX] activity of = 2%).<br><br>          -  Body weight = 10 kg.<br><br>          -  Subjects who have received FIX products (plasma-derived and/or recombinant FIX) for ><br>             150 exposure days (EDs) (6 to < 12 years), and > 50 EDs (< 6 years).<br><br>          -  No history of FIX inhibitor formation, no detectable inhibitors at Screening and no<br>             family history of inhibitors against FIX.<br><br>          -  Written informed consent for study participation.<br><br>        Exclusion Criteria:<br><br>          -  Known hypersensitivity to any FIX product or hamster protein.<br><br>          -  Known congenital or acquired coagulation disorder other than congenital FIX<br>             deficiency.<br><br>          -  Kidney or liver disease.<br><br>          -  Recent life-threatening bleeding episode.<br>