Inhibitors of non-structural protein 2 (NSP2) protease as therapeutics against venezuelan equine encephalitis virus

The National Institute of Allergy and Infectious Diseases awarded The University of Alabama in Huntsville $747,400 on August 18, 2026, under the Allergy and Infectious Diseases Research program (CFDA 93.855) to develop small molecule inhibitors of non-structural protein 2 (NSP2) protease as therapeutics against Venezuelan equine encephalitis virus.

The research advances lead candidate compounds through structure-activity relationship studies guided by NSP2 inhibition assays, in vitro antiviral and ADME assessments, pharmacokinetics, tolerability, and efficacy studies in mouse models. The project also investigates whether compounds protect the blood-brain barrier during VEEV infection using an organ-on-the-chip model in longitudinal studies. The compounds will be evaluated as first-in-class NSP2 protease inhibitors and serve as molecular tools to advance understanding of non-structural protein 2's role in alphavirus pathogenicity.

Period of performance runs through July 31, 2031. Place of performance is Huntsville, Alabama. The award is structured as a Project Grant, the standard assistance type for individual research initiatives under the program.

Abstract

Emerging viral infections caused by mosquito-borne alphaviruses are looming threats to public health systems. No vaccines or therapeutics are approved for human use against alphaviruses if regional or transnational outbreaks of alphavirus infections occur in the future. Loss of life and economic hardship can be minimized or prevented if therapeutic or prophylactic agents are avail- able. In this research project, we focus on investigating a series of molecules that inhibit the pro- tease domain of the non-structural protein 2 of veev, block the replication of veev in cell cultures and protect mice against veev, and are amenable to systematic structural changes essential for drug development. The overarching goal of this project is to advance new small molecule inhibi- tors of NSP2 and alphaviruses into preclinical development. The specific aims of this project are a). Improve potency of lead candidates through structure-activity relationship studies guided by NSP2 inhibition, in vitro antiviral and adme assays, pharmacokinetics, tolerability, and efficacy studies in mouse models; and (b). Investigate the ability of the compounds to protect the blood- brain barrier during veev infection using an organ-on-the-chip model of the BBB in longitudinal studies. The project goals will facilitate advancing the compound series toward clinical investiga- tions as first-in-class NSP2 protease inhibitors against veev. The molecules will also serve as valuable molecular tools to advance our understanding of the role of non-structural protein 2 in the pathogenicity of alphaviruses.