title: Factor VIII-Mimetic Function of Humanized Bispecific Antibody in Hemophilia A.
abstract: BACKGROUND
  In patients with severe hemophilia A, standard treatment is regular prophylactic and episodic intravenous infusions of factor VIII. However, these treatments are burdensome, especially for children, and may lead to the formation of anti-factor VIII alloantibodies (factor VIII inhibitors). Emicizumab (ACE910), a humanized bispecific antibody mimicking the cofactor function of factor VIII, was developed to abate these problems.
  
  
  METHODS
  We enrolled 18 Japanese patients with severe hemophilia A (with or without factor VIII inhibitors) in an open-label, nonrandomized, interindividual dose-escalation study of emicizumab. The patients received subcutaneous emicizumab weekly for 12 weeks at a dose of 0.3, 1.0, or 3.0 mg per kilogram of body weight (cohorts 1, 2, and 3, respectively). The end points were safety and pharmacokinetic and pharmacodynamic profiles. An additional, exploratory end point was the annualized bleeding rate, calculated as 365.25 times the number of bleeding episodes, divided by the number of days in the treatment period as compared with the 6 months before enrollment.
  
  
  RESULTS
  Emicizumab was associated with neither serious adverse events nor clinically relevant coagulation abnormalities. Plasma concentrations of emicizumab increased in a dose-dependent manner. Activated partial-thromboplastin times remained short throughout the study. The median annualized bleeding rates in cohorts 1, 2, and 3 decreased from 32.5 to 4.4, 18.3 to 0.0, and 15.2 to 0.0, respectively. There was no bleeding in 8 of 11 patients with factor VIII inhibitors (73%) and in 5 of 7 patients without factor VIII inhibitors (71%). Episodic use of clotting factors to control bleeding was reduced. Antibodies to emicizumab did not develop.
  
  
  CONCLUSIONS
  Once-weekly subcutaneous administration of emicizumab markedly decreased the bleeding rate in patients who had hemophilia A with or without factor VIII inhibitors. (Funded by Chugai Pharmaceutical; JapicCTI number, 121934.).
authors.affiliation: From Nara Medical University, Kashihara (M.S., K.N.), Ogikubo Hospital (H.H.), Tokyo Medical University (K.F.), and Chugai Pharmaceutical (N.F., K.Y., H.Y.), Tokyo, St. Marianna University School of Medicine, Kawasaki (M.T.), Nagoya University, Nagoya (T.M.), and University of Occupational and Environmental Health, Kitakyushu (T.S.) - all in Japan.
authors.forename: Midori
authors.initials: M
authors.lastname: Shima
authors.affiliation: From Nara Medical University, Kashihara (M.S., K.N.), Ogikubo Hospital (H.H.), Tokyo Medical University (K.F.), and Chugai Pharmaceutical (N.F., K.Y., H.Y.), Tokyo, St. Marianna University School of Medicine, Kawasaki (M.T.), Nagoya University, Nagoya (T.M.), and University of Occupational and Environmental Health, Kitakyushu (T.S.) - all in Japan.
authors.forename: Hideji
authors.initials: H
authors.lastname: Hanabusa
authors.affiliation: From Nara Medical University, Kashihara (M.S., K.N.), Ogikubo Hospital (H.H.), Tokyo Medical University (K.F.), and Chugai Pharmaceutical (N.F., K.Y., H.Y.), Tokyo, St. Marianna University School of Medicine, Kawasaki (M.T.), Nagoya University, Nagoya (T.M.), and University of Occupational and Environmental Health, Kitakyushu (T.S.) - all in Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Taki
authors.affiliation: From Nara Medical University, Kashihara (M.S., K.N.), Ogikubo Hospital (H.H.), Tokyo Medical University (K.F.), and Chugai Pharmaceutical (N.F., K.Y., H.Y.), Tokyo, St. Marianna University School of Medicine, Kawasaki (M.T.), Nagoya University, Nagoya (T.M.), and University of Occupational and Environmental Health, Kitakyushu (T.S.) - all in Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Matsushita
authors.affiliation: From Nara Medical University, Kashihara (M.S., K.N.), Ogikubo Hospital (H.H.), Tokyo Medical University (K.F.), and Chugai Pharmaceutical (N.F., K.Y., H.Y.), Tokyo, St. Marianna University School of Medicine, Kawasaki (M.T.), Nagoya University, Nagoya (T.M.), and University of Occupational and Environmental Health, Kitakyushu (T.S.) - all in Japan.
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Sato
authors.affiliation: From Nara Medical University, Kashihara (M.S., K.N.), Ogikubo Hospital (H.H.), Tokyo Medical University (K.F.), and Chugai Pharmaceutical (N.F., K.Y., H.Y.), Tokyo, St. Marianna University School of Medicine, Kawasaki (M.T.), Nagoya University, Nagoya (T.M.), and University of Occupational and Environmental Health, Kitakyushu (T.S.) - all in Japan.
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Fukutake
authors.affiliation: From Nara Medical University, Kashihara (M.S., K.N.), Ogikubo Hospital (H.H.), Tokyo Medical University (K.F.), and Chugai Pharmaceutical (N.F., K.Y., H.Y.), Tokyo, St. Marianna University School of Medicine, Kawasaki (M.T.), Nagoya University, Nagoya (T.M.), and University of Occupational and Environmental Health, Kitakyushu (T.S.) - all in Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Fukazawa
authors.affiliation: From Nara Medical University, Kashihara (M.S., K.N.), Ogikubo Hospital (H.H.), Tokyo Medical University (K.F.), and Chugai Pharmaceutical (N.F., K.Y., H.Y.), Tokyo, St. Marianna University School of Medicine, Kawasaki (M.T.), Nagoya University, Nagoya (T.M.), and University of Occupational and Environmental Health, Kitakyushu (T.S.) - all in Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Yoneyama
authors.affiliation: From Nara Medical University, Kashihara (M.S., K.N.), Ogikubo Hospital (H.H.), Tokyo Medical University (K.F.), and Chugai Pharmaceutical (N.F., K.Y., H.Y.), Tokyo, St. Marianna University School of Medicine, Kawasaki (M.T.), Nagoya University, Nagoya (T.M.), and University of Occupational and Environmental Health, Kitakyushu (T.S.) - all in Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Yoshida
authors.affiliation: From Nara Medical University, Kashihara (M.S., K.N.), Ogikubo Hospital (H.H.), Tokyo Medical University (K.F.), and Chugai Pharmaceutical (N.F., K.Y., H.Y.), Tokyo, St. Marianna University School of Medicine, Kawasaki (M.T.), Nagoya University, Nagoya (T.M.), and University of Occupational and Environmental Health, Kitakyushu (T.S.) - all in Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Nogami
mesh_terms: D000293:Adolescent; D000328:Adult; D018033:Antibodies, Bispecific / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use*; D002648:Child; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005164:Factor IX / Q000032:analysis; D005169:Factor VIII / Q000037:antagonists & inhibitors* / Q000627:therapeutic use; D005170:Factor X / Q000032:analysis; D006467:Hemophilia A / Q000150:complications / Q000188:drug therapy* / Q000276:immunology; D006470:Hemorrhage / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D007279:Injections, Subcutaneous / Q000009:adverse effects; D008297:Male; D008875:Middle Aged
chemical_list: D018033:Antibodies, Bispecific; D061067:Antibodies, Monoclonal, Humanized; C000608208:emicizumab; D005169:Factor VIII; D005164:Factor IX; D005170:Factor X