Article
作者: Rea, Catherine J ; Olsen, Eva H N ; Urbanus, Rolf T ; Faber, Johan H. ; Olsen, Ole H. ; Gandhi, Prafull S ; Løvgreen, Monika N ; Urbanus, Rolf T. ; Zivkovic, Minka ; de Bus, Ian-Arris ; Bloem, Karien ; Schluckebier, Gerd ; Gandhi, Prafull S. ; Olsen, Ole H ; Faber, Johan H ; Sørensen, Benny ; Rea, Catherine J. ; Schutgens, Roger E. ; Bonde, Amalie C. ; Johansson, Eva ; Bonde, Amalie C ; Løvgreen, Monika N. ; Bjørn, Søren E. ; Schutgens, Roger E ; Østergaard, Henrik ; Elm, Torben ; Olsen, Eva H. N. ; Bjørn, Søren E ; Alskär, Oskar
Abstract:Inherited bleeding disorders such as Glanzmann thrombasthenia (GT) lack prophylactic treatment options. As a result, serious bleeding episodes are treated acutely with blood product transfusions or frequent, repeated intravenous administration of recombinant activated coagulation factor VII (rFVIIa). Here we describe HMB-001, a bispecific antibody designed to bind and accumulate endogenous FVIIa and deliver it to sites of vascular injury by targeting it to the TREM (triggering receptor expressed on myeloid cells)-like transcript-1 (TLT-1) receptor that is selectively expressed on activated platelets. In healthy nonhuman primates, HMB-001 prolonged the half-life of endogenous FVIIa, resulting in its accumulation. Mouse bleeding studies confirmed antibody-mediated potentiation of FVIIa hemostatic activity by TLT-1 targeting. In ex vivo models of GT, HMB-001 localized FVIIa on activated platelets and potentiated fibrin-dependent platelet aggregation. Taken together, these results indicate that HMB-001 has the potential to offer subcutaneous prophylactic treatment to prevent bleeds in people with GT and other inherited bleeding disorders, with a low-frequency dosing regimen.