Human African trypanosomiasis was historically treated with regimens requiring hospitalization, lumbar puncture-based staging, and arsenic-derived drugs with lethal side effects. Fexinidazole changed the treatment model entirely.
Unlike the arsenic-derived and injectable regimens it displaced, fexinidazole is a nitroimidazole taken once daily for 10 days, activated inside the parasite to damage its DNA and proteins. It covers both the first and second stages of disease caused by Trypanosoma brucei gambiense.
Developed by the non-profit Drugs for Neglected Diseases initiative with Sanofi, fexinidazole reached approval through the FDA’s tropical disease priority review voucher pathway rather than a conventional commercial model. It is a reference case for neglected-disease development economics.
