Mpox Antiviral Clinical Trial Advances as WHO Extends Global Emergency
July 17, 2025
As the World Health Organization extends mpox’s global emergency status, NanoViricides’ NV-387 enters final preparations for Phase II clinical trials. Targeting Clade Ia and Ib monkeypox virus strains in Central Africa, NV-387 is an orally administered, host-mimetic antiviral designed to block viral entry at conserved host cell receptors. With no approved treatment proven effective in humans, NV-387 offers a potential breakthrough. Its unique design may limit viral resistance and provides a practical formulation for symptomatic patients. If successful, NV-387 could become the first antiviral with demonstrated efficacy against mpox, and a valuable addition to global bioterrorism preparedness.
The World Health Organization’s decision to extend mpox’s status as a Public Health Emergency of International Concern (PHEIC) underscores the urgent need for effective therapeutic options. Amid this backdrop, NanoViricides is advancing NV-387, a novel host-mimetic antiviral, into Phase II clinical trials targeting mpox Clade Ia and Ib infections. These strains, currently circulating in Central Africa, carry higher fatality rates than Clade IIb, which has dominated Western outbreaks.
NV-387 operates by mimicking heparan sulfate proteoglycans (HSPG), a common viral entry point, making viral resistance less likely. Unlike tecovirimat and brincidofovir—both of which have failed to show clinical efficacy or raised safety concerns—NV-387 demonstrated strong safety in Phase I human trials and preclinical models. Its orally dissolvable gummy formulation is especially suited for mpox patients with oral lesions that impede swallowing.
The upcoming adaptive Phase II trial in the Democratic Republic of the Congo (DRC) will assess safety, dosing, and antiviral effectiveness. If successful, NV-387 would be the first drug to demonstrate efficacy against mpox in humans. Regulatory filings are planned in Africa, followed by submissions to the U.S. FDA and European regulators.
While vaccines have been deployed across affected regions, administration has lagged due to logistical and funding constraints. Only 724,000 of 2.9 million doses have been used, and new cases continue to emerge in 17 African nations. The growing threat of Clade I importation into high-income countries elevates the importance of global preparedness.
NV-387’s development reflects the kind of strategic investment needed to bridge current gaps in mpox control and pandemic response more broadly. As global health security is increasingly tested by emerging threats, therapeutics like NV-387 could become essential tools—not only to manage mpox but also to prepare for future outbreaks and bioterrorism risks.