Browsing by Author "Demarest, James F"

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Open Access
Activity of Galidesivir in a Hamster Model of SARS-CoV-2.
(Viruses, 2021-12-21) Taylor, Ray; Bowen, Richard; Demarest, James F; DeSpirito, Michael; Hartwig, Airn; Bielefeldt-Ohmann, Helle; Walling, Dennis M; Mathis, Amanda; Babu, Yarlagadda S
Coronavirus disease 2019 (COVID-19) has claimed the lives of millions of people worldwide since it first emerged. The impact of the COVID-19 pandemic on public health and the global economy has highlighted the medical need for the development of broadly acting interventions against emerging viral threats. Galidesivir is a broad-spectrum antiviral compound with demonstrated in vitro and in vivo efficacy against several RNA viruses of public health concern, including those causing yellow fever, Ebola, Marburg, and Rift Valley fever. In vitro studies have shown that the antiviral activity of galidesivir also extends to coronaviruses. Herein, we describe the efficacy of galidesivir in the Syrian golden hamster model of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Treatment with galidesivir reduced lung pathology in infected animals compared with untreated controls when treatment was initiated 24 h prior to infection. These results add to the evidence of the applicability of galidesivir as a potential medical intervention for a range of acute viral illnesses, including coronaviruses.
Open Access
An update on the progress of galidesivir (BCX4430), a broad-spectrum antiviral.
(Antiviral research, 2021-09-20) Julander, Justin G; Demarest, James F; Taylor, Ray; Gowen, Brian B; Walling, Dennis M; Mathis, Amanda; Babu, YS
Galidesivir (BCX4430) is an adenosine nucleoside analog that is broadly active in cell culture against several RNA viruses of various families. This activity has also been shown in animal models of viral disease associated with Ebola, Marburg, yellow fever, Zika, and Rift Valley fever viruses. In many cases, the compound is more efficacious in animal models than cell culture activity would predict. Based on favorable data from in vivo animal studies, galidesivir has recently undergone evaluation in several phase I clinical trials, including against severe acute respiratory syndrome coronavirus 2, and as a medical countermeasure for the treatment of Marburg virus disease.
Unknown
Antiviral target compound profile for pandemic preparedness.
(Nature reviews. Drug discovery, 2024-12) Demarest, James F; Draghia-Akli, Ruxandra; Cihlar, Tomas; Bradley, Kenneth; Young, John AT; Chandra, Richa; Vaidyanathan, Sujata; Chu-Moyer, Margaret; Lynch, Christopher L; Campbell, Andrew; Saikatendu, Kumar Singh; Bilello, John P; Murata, Yoshihiko; van Loock, Marnix; Hurt, Aeron C; Tellinghuisen, Timothy; Ruggiero, Lee; Mackman, Richard; Hill, Nina M; Pottage, John C; INTREPID Alliance
Unknown
Brequinar and dipyridamole in combination exhibits synergistic antiviral activity against SARS-CoV-2 in vitro: Rationale for a host-acting antiviral treatment strategy for COVID-19.
(Antiviral research, 2022-10) Demarest, James F; Kienle, Maryline; Boytz, RuthMabel; Ayres, Mary; Kim, Eun Jung; Patten, JJ; Chung, Donghoon; Gandhi, Varsha; Davey, Robert A; Sykes, David B; Shohdy, Nadim; Pottage, John C; Kumar, Vikram S
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19) and the associated global pandemic resulting in >400 million infections worldwide and several million deaths. The continued evolution of SARS-CoV-2 to potentially evade vaccines and monoclonal antibody (mAb)-based therapies and the limited number of authorized small-molecule antivirals necessitates the need for development of new drug treatments. There remains an unmet medical need for effective and convenient treatment options for SARS-CoV-2 infection. SARS-CoV-2 is an RNA virus that depends on host intracellular ribonucleotide pools for its replication. Dihydroorotate dehydrogenase (DHODH) is a ubiquitous host enzyme that is required for de novo pyrimidine synthesis. The inhibition of DHODH leads to a depletion of intracellular pyrimidines, thereby impacting viral replication in vitro. Brequinar (BRQ) is an orally available, selective, and potent low nanomolar inhibitor of human DHODH that has been shown to exhibit broad spectrum inhibition of RNA virus replication. However, host cell nucleotide salvage pathways can maintain intracellular pyrimidine levels and compensate for BRQ-mediated DHODH inhibition. In this report, we show that the combination of BRQ and the salvage pathway inhibitor dipyridamole (DPY) exhibits strong synergistic antiviral activity in vitro against SARS-CoV-2 by enhanced depletion of the cellular pyrimidine nucleotide pool. The combination of BRQ and DPY showed antiviral activity against the prototype SARS-CoV-2 as well as the Beta (B.1.351) and Delta (B.1.617.2) variants. These data support the continued evaluation of the combination of BRQ and DPY as a broad-spectrum, host-acting antiviral strategy to treat SARS-CoV-2 and potentially other RNA virus infections.
Unknown
Reliable genotypic tropism tests for the major HIV-1 subtypes.
(Scientific reports, 2015-02-25) Cashin, Kieran; Gray, Lachlan R; Harvey, Katherine L; Perez-Bercoff, Danielle; Lee, Guinevere Q; Sterjovski, Jasminka; Roche, Michael; Demarest, James F; Drummond, Fraser; Harrigan, P Richard; Churchill, Melissa J; Gorry, Paul R
Over the past decade antiretroviral drugs have dramatically improved the prognosis for HIV-1 infected individuals, yet achieving better access to vulnerable populations remains a challenge. The principal obstacle to the CCR5-antagonist, maraviroc, from being more widely used in anti-HIV-1 therapy regimens is that the pre-treatment genotypic "tropism tests" to determine virus susceptibility to maraviroc have been developed primarily for HIV-1 subtype B strains, which account for only 10% of infections worldwide. We therefore developed PhenoSeq, a suite of HIV-1 genotypic tropism assays that are highly sensitive and specific for establishing the tropism of HIV-1 subtypes A, B, C, D and circulating recombinant forms of subtypes AE and AG, which together account for 95% of HIV-1 infections worldwide. The PhenoSeq platform will inform the appropriate use of maraviroc and future CCR5 blocking drugs in regions of the world where non-B HIV-1 predominates, which are burdened the most by the HIV-1 pandemic.