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.
Soil-transmitted nematodes (intestinal parasitic nematodes) are one of the most prevalent human parasites on earth, causing significant morbidity, especially in children; they are major drivers of impoverishment in developing countries. This application uses a novel, newly developed drug discovery pipeline and high- throughput screen (HTS) platform to screen two drug libraries for highly active compounds that target divergent intestinal nematode parasites. At the end of the proposed research, we expect to have discovered new compound(s) that have good-excellent therapeutic activity against the parasites in infected animals.
