Advances and challenges in the search for new treatments for Chagas disease.

Abstract

The treatment of Chagas disease (CD) has relied for more than five decades on two drugs, benznidazole (BZ) and nifurtimox (NTX), both with significant limitations and severe adverse effects. Their limited efficacy during the chronic phase underscores the urgent need for new chemotherapeutic strategies. The pursuit of new therapeutic agents for CD is focused on identifying molecular targets essential for Trypanosoma cruzi survival that are either absent or highly divergent in human, thereby enhancing selectivity and minimising off-target toxicity. These targets exploit the parasite's unique biology at multiple levels. Key metabolic vulnerabilities include: ergosterol biosynthesis, a sterol pathway distinct from human cholesterol metabolism; glycosomal metabolism, reflecting parasite´s unique compartmentalisation of glycolysis; and redox homeostasis, which depends on trypanothione rather than glutathione. Additional promising avenues involve the parasite's genetic and epigenetic regulation, mRNA processing and translational control. Furthermore, virulence-associated factors, and specific enzymes such as type I nitroreductase (NTR-1) can be exploited for selective prodrug activation. The complex genomic organisation and pronounced plasticity of T. cruzi complicate the identification of novel therapeutic targets. The abundance of proteins annotated as hypothetical or of unknown function further obscure critical metabolic pathways that could serve as druggable targets. In this context, the discovery of new drugs for CD strategically integrates phenotypic, target-based, and computational approaches, all of which require rigorous validation through preclinical in vitro and in vivo studies. Although modern approaches have yielded several promising lead compounds, successfully controlling CD will also depend on overcoming socioeconomic and access-related barriers to ensure that new therapies reach the populations most affected by this neglected tropical disease.