title: Cell based in vitro and ex vivo models in metabolic disease drug discovery: nice to have or critical path?
abstract: BACKGROUND
  The use of cellular models as tools in drug discovery is almost universal. However, in disease areas such as metabolic diseases, are they relevant to the process and do they add value?
  
  
  OBJECTIVE
  In this article, we explore the variety of cellular models now used in drug discovery in metabolic diseases as revealed by publication. We have tried to make some connections between drug phenotypes in these models with clinical parallels. We also ask the question as to whether such models add value in the drug discovery process. This overview is not about recombinant cell systems used in target-based screening; rather, we focus on in vitro, including ex vivo, models as physiological systems in drug discovery in obesity and diabetes.
  
  
  CONCLUSIONS
  In terms of building target confidence, in vitro models are often the only mechanistic link to human systems early in a projects life. Many of the current targets in metabolic diseases in the early discovery phase are not yet clinically supported, let alone validated. In this respect, therefore, in vitro models warrant a place in the critical path in early discovery. In terms of any predictive role for decision-making today, this is much more difficult and is more likely pushed to a supporting role as part of a wider package. However, there is a rapid rate of advancement in this field and future developments hold much promise.
authors.affiliation: Departments of Bioscience, AstraZeneca R&D Mölndal, Sweden +46 31 7064339 ; +46 31 7763700 ; stefan.hallen@astrazeneca.com.
authors.forename: Stefan
authors.initials: S
authors.lastname: Hallén
authors.forename: John C
authors.initials: JC
authors.lastname: Clapham