THE CHALLENGE
Since the outbreak of SARS-CoV-2 several million people got infected with this virus and several hundred thousand people already died due to the consequences of COVID-19. Coronaviruses are a recurring and ongoing pandemic of the 21st century. In the last two decades three coronaviruses emerged, SARS, MERS and SARS-CoV-2, and caused life-threatening diseases. So far, no vaccine or specific antiviral therapy for SARS-CoV-2 exist. Current repurposed drugs in clinical development either have many side effects or have a high risk for the development of drug resistances, because they target components of the genetically variable viruses. Therefore, an urgent medical need for a reliable and tolerable broad-spectrum antiviral drug without the risk of resistant virus variations exists.