TKK130 is a 3-Hydroxy-Propanamidine (HPA) with Potent Antimalarial In Vivo Activity and a High Barrier to Resistance

Malaria continues to pose a significant burden on populations in endemic areas and requires innovative treatment options. Here, we report the synthesis and preclinical evaluation of the novel 3-hydroxypropanamidine (HPA) 2 (TKK130), which shows excellent antiplasmodial in vitro activity against drug-sensitive and -resistant Plasmodium falciparum strains. Moreover, in various human cell lines, the compound shows no cytotoxicity and excellent parasite selectivity. The compound inhibits synthetic hemozoin (β-hematin) formation, with IC50 values lower than chloroquine (CQ), and its in vitro rate of activity is comparable with the fast-acting antimalarial drug dihydroartemisinin. Furthermore, selection studies reveal a very low propensity for resistance development. Based on initial in vivo pharmacokinetic snapshot data, 2 (TKK130) has a long-lasting, linear pharmacokinetic profile. In vivo, this novel HPA exhibits curative activity in the Plasmodium bergheimouse model and potent activity in theP. falciparum SCID mouse model after oral administration.