Fig. 1.

Classical pipeline for drug discovery highlighting scientific and non-scientific challenges. The process often starts with basic research in order to (i) identify and validate molecular/biochemical targets (target-based assays) or (ii) develop and validate phenotypic assays (cell-based assays), in which compounds are tested against the whole parasite or a given biological system. Medicinal chemistry experts will then optimize selected compounds (hits). Next steps consist in testing candidates in animal models and assessing their performances by determining pharmacokinetics and pharmacodynamics properties. Finally, a compound is targeted to clinical trials in humans and, once showing a satisfactory profile, it is defined as a drug candidate. The last steps of the pipeline include registration and manufacture of the medicine.