title: Rational design of antirheumatic prodrugs specific for sites of inflammation.
abstract: OBJECTIVE
  Biologic drugs, such as the anti-tumor necrosis factor (anti-TNF) antibody adalimumab, have represented a breakthrough in the treatment of rheumatoid arthritis. Yet, concerns remain over their lack of efficacy in a sizable proportion of patients and their potential for systemic side effects such as infection. Improved biologic prodrugs specifically targeted to the site of inflammation have the potential to alleviate current concerns surrounding biologic anticytokine therapies. The purpose of this study was to design, construct, and evaluate in vitro and ex vivo the targeting and antiinflammatory capacity of activatable bispecific antibodies.
  
  
  METHODS
  Activatable dual variable domain (aDVD) antibodies were designed and constructed to target intercellular adhesion molecule 1 (ICAM-1), which is up-regulated at sites of inflammation, and anti-TNF antibodies (adalimumab and infliximab). These bispecific molecules included an external arm that targets ICAM-1 and an internal arm that comprises the therapeutic domain of an anti-TNF antibody. Both arms were linked to matrix metalloproteinase (MMP)-cleavable linkers. The constructs were tested for their ability to bind and neutralize both in vitro and ex vivo targets.
  
  
  RESULTS
  Intact aDVD constructs demonstrated significantly reduced binding and anti-TNF activity in the prodrug formulation as compared to the parent antibodies. Human synovial fluid and physiologic concentrations of MMP enzyme were capable of cleaving the external domain of the antibody, revealing a fully active molecule. Activated antibodies retained the same binding and anti-TNF inhibitory capacities as the parent molecules.
  
  
  CONCLUSIONS
  The design of a biologic prodrug with enhanced specificity for sites of inflammation (synovium) and reduced specificity for off-target TNF is described. This construct has the potential to form a platform technology that is capable of enhancing the therapeutic index of drugs for the treatment of RA and other inflammatory diseases.
authors.affiliation: William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, and Queen Mary University of London, London, UK.
authors.forename: Shimobi C
authors.initials: SC
authors.lastname: Onuoha
authors.affiliation: William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, and Queen Mary University of London, London, UK.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Ferrari
authors.affiliation: University of Trieste, Trieste, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Sblattero
authors.affiliation: William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, and Queen Mary University of London, London, UK.
authors.forename: Costantino
authors.initials: C
authors.lastname: Pitzalis
mesh_terms: D000068879:Adalimumab / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D018033:Antibodies, Bispecific / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D018501:Antirheumatic Agents / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D055808:Drug Discovery; D006801:Humans; D007249:Inflammation / Q000188:drug therapy* / Q000378:metabolism; D000069285:Infliximab / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D020782:Matrix Metalloproteinases / Q000378:metabolism; D011355:Prodrugs / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D012107:Research Design; D013583:Synovial Membrane / Q000187:drug effects / Q000378:metabolism
chemical_list: D018033:Antibodies, Bispecific; D018501:Antirheumatic Agents; D011355:Prodrugs; D018799:Intercellular Adhesion Molecule-1; D000069285:Infliximab; D020782:Matrix Metalloproteinases; D000068879:Adalimumab