Drug Repurposing Approaches for the Treatment of Influenza Viral Infection: Reviving Old Drugs to Fight Against a Long-Lived Enemy

Abstract

Influenza viruses still constitute a real public health problem today. To cope with the emergence of new circulating strains, but also the emergence of resistant strains to classic antivirals, it is necessary to develop new antiviral approaches. This review summarizes the state-of-the-art of current antiviral options against influenza infection, with a particular focus on the recent advances of anti-influenza drug repurposing strategies and their potential therapeutic, regulatory and economic benefits. The review will illustrate the multiple ways to reposition molecules for the treatment of influenza, from adventitious discovery to in silico-based screening. These novel antiviral molecules, many of which targeting the host cell, in combination with conventional antiviral agents targeting the virus, will ideally enter the clinics and reinforce the therapeutic arsenal to combat influenza virus infections.

Keywords: antiviral resistance; antivirals; drug combination; drug discovery; drug repositioning; drug repurposing; influenza virus; transcriptional profiling.

Figure 1

From the bench to the bedside: comparison between de novo drug development and drug repurposing. De novo (classic) drug development constitutes a time-consuming and expensive process. From initial discovery to market, it generally takes 13–15 years and costs up to US$ 2 billion, with a very low success rate (10%). In contrast, drug repurposing approaches offer several advantages. Indeed, the time frame from discovery to market is shorter (5–11 years), less expensive (US$ 350 million), and with a higher success rate (30%), mostly because a large part of preclinical and clinical testings (e.g., safety, formulation, posology) have been already performed for the drug's initial therapeutic indication (41, 42).