“…The propagation of C. parvum (Iowa isolate) in calves and oocyst purification [34][35][36][37], synthesis of BKIs [22,25,27,38], in vitro CpCDPK1 enzyme assay [22,25,38], in vitro determination of C. parvum BKI sensitivity [22,25,38,39], neonatal mouse [36,40] and calf models of C. parvum infection [37,[41][42][43], and pharmacologic measurement of BKI plasma and stool levels and plasma protein binding have all been previously described [27,44]. BKI-1294 and BKI-1553 were synthesized on the pyrazolo [2,3-d] pyrimidine scaffold, while BKI-1517 was synthesized on a 5-aminopyrazole-4-carboxamide scaffold [25] (Figure 1).…”