title: Safety, tolerability, pharmacokinetics, pharmacodynamics and efficacy of the monoclonal antibody ASK8007 blocking osteopontin in patients with rheumatoid arthritis: a randomised, placebo controlled, proof-of-concept study.
abstract: OBJECTIVE
  Osteopontin is an extracellular matrix protein with diverse immunomodulatory functions. The authors assessed the safety, tolerability, pharmacokinetics, pharmacodynamics and initial efficacy of the humanised monoclonal antibody ASK8007, which blocks osteopontin.
  
  
  METHODS
  In this double-blind, multicentre, combined first-in-man, single-dose escalation (phase I, part A) and proof-of-concept, multiple-dose (phase IIA, part B) study, rheumatoid arthritis (RA) patients with active disease were randomly assigned to receive ASK8007 or placebo intravenously. Safety monitoring, pharmacokinetic and pharmacodynamic analyses and clinical assessments were performed throughout the study. The expression of phenotypic cell markers was evaluated in synovial tissue biopsy samples obtained at baseline and 43 days after initiation of treatment (part B) by immunohistochemistry and digital image analysis. Two co-primary efficacy endpoints were the change from baseline in the disease activity score evaluated in 28 joints (DAS28) and the change from baseline in the number of CD68 synovial sublining macrophages, both assessed on day 43 (part B).
  
  
  RESULTS
  ASK8007 was overall safe and well tolerated up to the highest studied dose (20 mg/kg). Quantifiable concentrations of ASK8007 were detected in synovial fluid. No differences were observed for changes from baseline in DAS28 and CD68 sublining macrophages between ASK8007 and placebo-treated patients. Within the ASK8007 treatment group, there were also no apparent clinical responses or changes in sublining macrophages. In addition, ASK8007 treatment did not change other assessed biomarkers.
  
  
  CONCLUSIONS
  Osteopontin blockade is well tolerated and not related to safety concerns. These results consistently show that osteopontin blockade is unlikely to induce robust clinical improvement in RA patients.
authors.affiliation: Division of Clinical Immunology and Rheumatology, Academic Medical Center/University of Amsterdam, The Netherlands.
authors.forename: M J H
authors.initials: MJ
authors.lastname: Boumans
authors.forename: J G A
authors.initials: JG
authors.lastname: Houbiers
authors.forename: P
authors.initials: P
authors.lastname: Verschueren
authors.forename: H
authors.initials: H
authors.lastname: Ishikura
authors.forename: R
authors.initials: R
authors.lastname: Westhovens
authors.forename: E
authors.initials: E
authors.lastname: Brouwer
authors.forename: B
authors.initials: B
authors.lastname: Rojkovich
authors.forename: S
authors.initials: S
authors.lastname: Kelly
authors.forename: M
authors.initials: M
authors.lastname: den Adel
authors.forename: J
authors.initials: J
authors.lastname: Isaacs
authors.forename: H
authors.initials: H
authors.lastname: Jacobs
authors.forename: J
authors.initials: J
authors.lastname: Gomez-Reino
authors.forename: G M
authors.initials: GM
authors.lastname: Holtkamp
authors.forename: A
authors.initials: A
authors.lastname: Hastings
authors.forename: D M
authors.initials: DM
authors.lastname: Gerlag
authors.forename: P P
authors.initials: PP
authors.lastname: Tak
mesh_terms: D000328:Adult; D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000009:adverse effects* / Q000493:pharmacokinetics / Q000627:therapeutic use; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D018501:Antirheumatic Agents / Q000009:adverse effects* / Q000493:pharmacokinetics / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D001799:Blood Sedimentation; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006207:Half-Life; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D053495:Osteopontin / Q000037:antagonists & inhibitors* / Q000097:blood; D012720:Severity of Illness Index; D013583:Synovial Membrane / Q000276:immunology; D016896:Treatment Outcome; D000097382:CD68 Molecule
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D018501:Antirheumatic Agents; D015415:Biomarkers; D018836:Inflammation Mediators; D053495:Osteopontin; C570079:ASK8007 monoclonal antibody; C067980:CD68 antigen, human; D000097382:CD68 Molecule