Prolonged half-life and preserved enzymatic properties of factor IX selectively PEGylated on native N-glycans in the activation peptide

作者：Ostergaard Henrik^*; Bjelke Jais R; Hansen Lene; Petersen Lars Christian; Pedersen Anette A; Elm Torben; Moller Flemming; Hermit Mette B; Holm Pernille K; Krogh Thomas N; Petersen Jorn M; Ezban Mirella; Sorensen Brit B; Andersen Mette D; Agerso Henrik; Ahmadian Haleh; Balling Kristoffer W; Christiansen Marie Louise S; Knobe Karin; Nichols Timothy C; Bjorn Soren E; Tranholm Mikael

来源：Blood, 2011, 118(8): 2333-2341.

DOI：10.1182/blood-2011-02-336172

Current management of hemophilia B entails multiple weekly infusions of factor IX (FIX) to prevent bleeding episodes. In an attempt to make a longer acting recombinant FIX (rFIX), we have explored a new releasable protraction concept using the native N-glycans in the activation peptide as sites for attachment of polyethylene glycol (PEG). Release of the activation peptide by physiologic activators converted glycoPEGylated rFIX (N9-GP) to native rFIXa and proceeded with normal kinetics for FXIa, while the Km for activation by FVIIa-tissue factor (TF) was increased by 2-fold. Consistent with minimal perturbation of rFIX by the attached PEG, N9-GP retained 73%-100% specific activity in plasma and whole-blood-based assays and showed efficacy comparable with rFIX in stopping acute bleeds in hemophilia B mice. In animal models N9-GP exhibited up to 2-fold increased in vivo recovery and a markedly prolonged half-life in mini-pig (76 hours) and hemophilia B dog (113 hours) compared with rFIX (16 hours). The extended circulation time of N9-GP was reflected in prolonged correction of coagulation parameters in hemophilia B dog and duration of effect in hemophilia B mice. Collectively, these results suggest that N9-GP has the potential to offer efficacious prophylactic and acute treatment of hemophilia B patients at a reduced dosing frequency. (Blood. 2011; 118(8): 2333-2341)

• 出版日期2011-8-25