The most promising inhibitors of coronavirus replication emerging from WP1-4 will be evaluated in cell culture and in vitro models (WP5) to assess the many properties that determine whether a compound can be developed into an actual drug. In a next step, the compounds will be evaluated ex vivo in primary human airway epithelial cultures, which represent the human lung epithelium. Finally, we will assess the in vivo efficacy of the most promising compounds in two animal models (Syrian golden hamsters and humanized ACE2 mice) to obtain final proof-of-concept.