Soil-transmitted helminth or soil-transmitted nematode (STN) infections are intestinal parasitic
nematodes, mainly Ascaris, hookworms, and whipworms. They are amongst the most prevalent parasites
on earth and cause severe morbidity in children, including growth stunting, intellectual and educational
impairment, malnutrition, anemia, and lower future earning; they also have significant impacts on
pregnant women and worker productivity. Single dose mass drug administration (MDA) to treat STNs
relies on a single drug class, the benzimidazoles (BZs). BZs have poor efficacy against whipworms and
highly variable efficacy against hookworms. BZ resistance alleles have been detected in STNs and there are
clear examples of low BZ efficacy against all parasites. New mechanism-of-action and broadly potent
therapies for STNs are urgently needed. However, high throughput screening (HTS) platforms using STN
parasites have not been developed to date, which would greatly facilitate drug discovery. Here, a new
pipeline for STN drug discovery using two highly divergent STN parasites is described and validated, as is a
new HTS platform that is incorporated at the beginning of the pipeline (Z factor 0.53). The overall
objective of this application is to identify safe compounds that can broadly target STN parasites by applying
this new HTS platform and pipeline. Two high-quality and well-characterized libraries containing 21,153
compounds will be screened. Actives (~1800 predicted) from this HTS will be down-selected by screening
against adult Ancylostoma ceylanicum hookworm adult parasites and against Trichuris muris whipworm
adult parasites, both which are highly relevant for human STN drug discovery. Compounds that are dually
active against these divergent parasites will be further prioritized by data mining/chemoinformatics,
mammalian cell toxicity studies, BZ-resistant hookworm assays, as well as in vitro dose-response studies
against adult parasites from both species. The top 10-20 actives from these studies will be tested in rodents
for in vivo deworming efficacy against genuine parasitic infections. Following these studies, in vivo
pharmacokinetic (PK) studies, focused library and Structure-Activity-Relationship studies, and initial
mechanism of action (MoA) studies will be carried out. This research will lay the groundwork for more
detailed follow up studies for future applications. After successful execution of this proposed research plan,
we expect to have identified 1-4 new, broadly active anti-STN compounds (anthelmintics) primed for future
pre-clinical and clinical studies.
