title: DAS181, a sialidase fusion protein, protects human airway epithelium against influenza virus infection: an in vitro pharmacodynamic analysis.
abstract: OBJECTIVE
  The influenza virus (IFV) infection models commonly used to evaluate antiviral agents (e.g. MDCK cell line and mice) are limited by physiological differences from the human respiratory tract in vivo. Here we report the pharmacodynamics of DAS181, a sialidase fusion protein that inhibits influenza infection, in the model systems of well-defined human airway epithelium (HAE) culture and ex vivo culture of fresh human bronchial tissue, both of which are close mimics of the human respiratory tract in vivo.
  
  
  METHODS
  HAE culture and ex vivo human bronchi were used to evaluate the sialic acid removal and regeneration efficiency and IFV inhibition after various DAS181 treatment levels and regimens.
  
  
  RESULTS
  DAS181 effectively desialylates HAE cultures and ex vivo bronchi tissues and therefore potently inhibits replication of different IFV strains. The treatment effect of DAS181 occurs immediately upon application to the epithelial surface and is unaffected by the respiratory mucus. In both HAE and human bronchial tissue, the inhibitory effect of DAS181 treatment lasts for at least 2 days. Approximately 80% epithelial surface desialylation and significant anti-IFV efficacy can be achieved at topical concentrations of DAS181 in the range of 5-10 microg/cm(2) when applied once daily. An additional treatment or a higher loading dose of DAS181 on the first day provides significant additional treatment benefit. Comparing the effect of DAS181 versus its two analogues, DAS180 and DAS185, has confirmed that sialidase function is critical for DAS181, and the cell-binding domain (amphiregulin tag) prolongs DAS181 retention and potentiates its function.
  
  
  CONCLUSIONS
  These results provide valuable insights into DAS181 treatment dose and potential regimens in the clinical setting.
authors: NexBio, Inc., San Diego, CA, USA.
authors: Gallen B
authors: GB
authors: Triana-Baltzer
authors: Maria
authors: M
authors: Babizki
authors: Michael C W
authors: MC
authors: Chan
authors: Adam C N
authors: AC
authors: Wong
authors: Laura M
authors: LM
authors: Aschenbrenner
authors: Erin R
authors: ER
authors: Campbell
authors: Qi-Xiang
authors: QX
authors: Li
authors: Renee W Y
authors: RW
authors: Chan
authors: J S Malik
authors: JS
authors: Peiris
authors: John M
authors: JM
authors: Nicholls
authors: Fang
authors: F
authors: Fang
mesh_terms: D000998:Antiviral Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D002478:Cells, Cultured; D004848:Epithelium / Q000821:virology*; D006801:Humans; D007251:Influenza, Human / Q000517:prevention & control*; D009924:Organ Culture Techniques; D009975:Orthomyxoviridae / Q000187:drug effects*; D011993:Recombinant Fusion Proteins / Q000493:pharmacokinetics / Q000494:pharmacology*
chemical_list: D000998:Antiviral Agents; D011993:Recombinant Fusion Proteins; C525612:oplunofusp