ACT-451840

ACT-451840 is an investigational synthetic small molecule antimalarial drug originally developed by Actelion Pharmaceuticals. It is a piperazine-containing compound with potent activity against both sensitive and resistant strains of *Plasmodium falciparum*, including artemisinin-resistant strains. The drug targets all asexual blood stages of the parasite (rings, trophozoites, and schizonts) and has a rapid onset of action. Notably, it also inhibits gametocyte development and male gamete formation in vitro, conferring transmission-blocking potential. Preclinical studies demonstrated efficacy in murine models infected with human malaria parasites as well as ex vivo activity against *P. vivax*. In clinical trials (Phase 1), ACT-451840 showed significant reduction in parasitemia after single or multiple oral doses in healthy volunteers experimentally infected with malaria parasites[2][4][5][6][8]. Its mechanism of action appears distinct from current antimalarials; it is classified as an aspartic endopeptidase inhibitor[7].