Trypanocidal Agents that Kill Multiple Stages of the Trypanosoma cruzi Life Cycle

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Chagas disease is a neglected tropical disease and has been designated as a research priority by NIAID and an SBIR Research Topic of Interest. Six million individuals are infected and 8,000 deaths were caused by in 2015 in mostly Central and South America by advanced forms of the disease such as Chagas hemorrhagic fever. The cost associated with Chagas disease treatment globally is estimated to be ~$7 billion. Chagas disease is caused by the parasitic protist Trypanosoma cruzi (T. cruzi) and spread by Triatominae, or "kissing bugs". It is endemic in South America, but is spread to people living elsewhere due to immigration of infected patients and travel to endemic regions. No vaccine is currently available and the only drugs used to treat, the nitro aryl compounds nifurtimox and benznidazole, lose effectiveness in the chronic phase as the parasite develops resistance and they cause limiting adverse events as well. New medications acting via novel mechanisms are urgently needed to eliminate the parasite in chronic patients suffering and dying from Chagas disease. Novel compounds synthesized at Fox Chase Chemical Diversity Center (FCCDC) and tested at the GSK Tres Cantos Open Lab Foundation in Tres Cantos, Spain, a research facility dedicated to curing neglected tropical diseases, are display excellent activity against the T. cruzi parasite in both its replicative (amastigote) and infective (trypomastigote) forms as found in phenotypic screening assays. The compounds do not act through any known mechanism and display little to no toxicity to host cells, unlike the standard of care nifurtimox and benznidazole. Further, the hit compounds identified so far are proprietary to FCCDC and are readily amenable to further SAR development by medicinal chemistry hit to lead optimization. Very importantly, the activity seen for the compounds tested so far are trypanocidal, killing the parasite, and not only static, generating a profile of activity which has generated great interest at the Tres Cantos testing facility. We plan to exploit the activity of our preliminary compound library by: 1) Developing the SAR of our novel chemotype with the ultimate aim of synthesizing development candidates to treat acute and chronic Chagas disease (FCCDC), 2) characterizing the biochemical properties of the compounds (Tres Cantos), and 3) performing in vivo tests in an acute Chagas Disease mouse model (NYU) as well evaluation and improving ADME properties of advanced leads. The biological characterization at Tres Cantos will entail four assays to gauge anti-parasitic activity and host cell toxicity. Unlike other molecules being researched for treating Chagas disease, our molecules lack reactive functional groups routinely associated with toxicity and adverse side effects. At the end of Phase I we expect to fully qualify 2-3 novel small molecules as leads suitable for advanced profiling in a Phase II SBIR period of study. The long term goal of the program is to complete all of the studies necessary for filing an Investigational New Drug (IND) application for new agents to treat Chagas Disease as monotherapy or in combination with existing agents.