# A single antiviral to treat multiple opportunistic infections

> **NIH NIH R44** · EVRYS BIO, LLC · 2024 · $983,882

## Abstract

PROJECT SUMMARY/ABSTRACT
Immunosuppressed transplant patients have heightened susceptibility to environmental pathogens as well as
adventitious agents traveling with donor tissues or resident in the recipient. Traditional therapies target the virus
and are thereby limited in effectiveness to the specific virus targeted. Evrys Bio is developing orally administered,
broad-spectrum antivirals that target the host-cell sirtuin-2 protein (SIRT2). In vitro feasibility was
demonstrated in SBIR Phase I for an early lead, FLS-359, showing broad effectiveness against four families of
viruses posing problems for immunosuppressed transplant patients: herpesviruses, polyomaviruses, hepatitis
viruses, and respiratory viruses. Additionally, SIRT2-targeting with FLS-359 blocked acquisition of viral drug
resistance in an influenza model and was additive in antiviral activity with traditional direct-acting antivirals. A
prototype was developed in SBIR Phase II, allowing selection of a Drug Candidate (DC) for Investigational New
Drug (IND)-enablement that satisfied the in vitro Target Compound Profile with respect to antiviral potency and
ADME, and in vivo oral bioavailability, target engagement, and tolerability. The DC is designated EV-100. In this
SBIR Phase IIB application, we request funding to advance EV-100 toward an IND filing. The clinical trial will
be designed to test the utility of EV-100 for prophylaxis of human cytomegalovirus (HCMV) infection and disease
in adult HCMV-seropositive recipients of an allogeneic hematopoietic stem cell transplant. To advance to the
IND filing, we will establish relationships between EV-100 dose, pharmacokinetic parameters, efficacy, and
toxicity. We will conduct non-GLP dose range finding safety studies in rats and dogs, and efficacy studies in
murine HCMV viral challenge models to provide guidance and minimize risk with dosing regimen selection for
costly GLP and clinical studies. In addition, we will perform studies to address published FDA in vitro virology
study recommendations that will support an IND filing. These studies will include the assessment of EV-100
antiviral activity versus multiple laboratory and clinical HCMV isolates, including the analysis of EV-100
inhibitory activity toward HCMV variants that are resistant to currently approved drugs; testing for the evolution
of viral drug resistance during serial passage of HCMV in increasing concentrations of EV-100 in cell culture;
evaluation of EV-100 efficiency in combination with currently approved anti-HCMV drugs; delineation of EV-
100 as a function of HCMV dose; and additional parameters that help to predict the efficacy of EV-100 in
transplant recipients. Finally, although HCMV prophylaxis is the intended initial indication, the broad-spectrum
antiviral profile against human viruses is a potential breakthrough feature of EV-100. The drug has already been
shown to inhibit both RNA and DNA viruses in addition to HCMV that can threaten both the organ and th...

## Key facts

- **NIH application ID:** 10825625
- **Project number:** 5R44AI114079-06
- **Recipient organization:** EVRYS BIO, LLC
- **Principal Investigator:** Stacy Remiszewski
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $983,882
- **Award type:** 5
- **Project period:** 2014-06-15 → 2025-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10825625

## Citation

> US National Institutes of Health, RePORTER application 10825625, A single antiviral to treat multiple opportunistic infections (5R44AI114079-06). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10825625. Licensed CC0.

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