Fexinidazole

Human African trypanosomiasis (HAT, also colloquially referred to as sleeping sickness), caused by T. brucei gambiense and T. brucei rhodesiense, remains a moderate risk (>1/10,000 inhabitants per year in endemic areas) despite focussed control efforts. Transmitted by the bite of an infected tsetse fly, HAT is biphasic with a first (hemolymphatic) stage that progresses to a second (meningoencephalitic) stage in which patients experience progressively worsening neurological symptoms and eventually die if left untreated. Historical treatment options for meningoencephalitic HAT include melarsoprol, eflornithine, and nifurtimox/eflornithine combination therapy (NECT), though melarsoprol is highly toxic and each treatment requires lengthy infusions that are difficult to administer in resource-limited settings. Fexinidazole, which was originally developed in the 1970s/80s by Hoechst AG and subsequently rediscovered through the Drugs for Neglected Diseases Initiative (DNDi) in 2005, is the first all-oral treatment for first and second stage HAT caused by T. brucei gambiense. Fexinidazole received a positive opinion from the European Medicines Agency (EMA) in November 2018 and was approved by the FDA on July 16, 2021. It is currently marketed by Sanofi-Aventis.