Low Bleeding Rates with Increase or Maintenance of Physical Activity in Patients Treated with Recombinant Factor IX Fc Fusion Protein (rFIXFc) in the B-LONG and Kids B-LONG Studies - Kulkarni, Roshni; Shapiro, Amy D; Windyga, Jerzy; Ragni, Margaret V; Pasi, K John; Ozelo, Margareth Castro; Tsao, Elisa; Mei, Baisong (Blood, 2015)