Purfalcamine is an orally active, selective Plasmodium falciparum calcium-dependent protein kinase 1 (PfCDPK1) inhibitor with an IC50 of 17 nM and an EC50 of 230 nM, exhibiting antimalarial activity by inducing developmental arrest of malaria parasites at the schizont stage[1][2].

Purfalcamine exhibits limited activity against Toxoplasma gondii calcium-dependent protein kinase 3 (TgCDPK3)[1] and does not impact parasitemia levels within the initial 32 hours. However, parasite levels stabilize and subsequently decrease post 40-hour exposure[1]. It effectively inhibits P. falciparum strains (3D7, Dd2, FCB, HB3, and W2) proliferation, with EC50 values ranging from 171 to 259 nM, suggesting its efficacy against drug-resistant parasites. Notably, with an EC50 of 230 nM for the P. falciparum 3D7 strain, Purfalcamine demonstrates a significant therapeutic margin of 23 to 36 times against various human cell lines (CHO, HEp2, HeLa, and Huh7), with EC50s between 5.476 μM and 12.33 μM[1].

Purfalcamine (10 mg/kg; oral gavage; BID; for 6 days) delays the onset of parasitemia in treated mice[1]. Purfalcamine (20 mg/kg; orally gavage) exhibits a Cmax of 2.6 μM with a half-life of 3.1 hours[1]. Animal Model: Male BALB/c mice, 7 weeks of age, with the malaria parasite[1].