Development of Small Molecule Therapeutics Targeting Hemorrhagic Fever Viruses - The ultimate goal of this Phase I application is to develop novel small molecule, broad-spectrum
therapeutics against viral infections caused by filoviruses that depend on the PPxY L-domain motif for
virus egress and spread of infection. Ebola (EBOV) and Marburg (MARV) viruses are highly
pathogenic and classified as Category A, high-priority bioterror pathogens. As there are no
commercially available therapeutic agents for the treatment of these viral infections, our identification
of virus-host inhibitors that may prevent virus spread will fill a significant unmet need. Indeed,
development of such inhibitors is becoming more urgent, as EBOV can cross the blood-brain barrier
and re-emerge months later in the CNS, semen, and other immunologically privileged sites that are
inaccessible to antibody therapy. Our proposed anti-viral therapeutic that targets EBOV and MARV is
expected to be used for treatment of infected individuals as well as in prophylactic treatment of
soldiers, healthcare workers, or others at high risk. We postulate that emergency administration of
such an antiviral therapeutic during an outbreak would inhibit virus dissemination in infected
individuals and reduce the efficacy of infection in newly exposed individuals, thus slowing disease
progression, allowing for more effective viral clearance by the immune system, and preventing further
viral transmission. As these host-oriented inhibitors are broad-spectrum, they are likely to be effective
against newly emerging viruses as well as viral variants. Indeed, we predict that targeting a virus-host
interaction necessary for efficient virus egress and dissemination will greatly diminish or eliminate the
occurrence of drug resistant viral mutations and may lead to a paradigm shift in the search for better
antiviral drugs. Importantly, as these virus-host interactions represent a common mechanism in a
range of RNA viruses, we predict that they represent an Achilles’ heel in the life cycle of many RNA
virus pathogens. Our aims include 1) optimization of current lead inhibitors to achieve adequate drug
properties for proof of concept testing in Ebola and Marburg mouse models; 2) evaluate compounds
for their ability to specifically inhibit PPxY-Nedd4 interaction and subsequent virus egress;3) evaluate
ADME/PK properties for compounds meeting criteria of Specific Aim 2; 4) evaluate lead inhibitors
using in vitro and in vivomodels of authentic hemorrhagic fever viruses. Our goals will be
accomplished by combining the pharmaceutical and medicinal chemistry expertise of the scientists at
the Fox Chase Chemical Diversity Center (FCCDC) with the expertise and experience of the Harty
Lab at the University of Pennsylvania in the experimental aspects of antiviral therapy, and with the
small animal model and filovirus expertise of the BSL-4 laboratory of Dr. Robert Davey at Texas
Biomedical Research Institute.