FDA Reviews NV-387: A Breakthrough MPox Drug Amid Outbreaks

SHELTON, CT / ACCESS Newswire / April 1, 2026 / NanoViricides, Inc. (NYSE American: NNVC) (the "Company") today announced that a Phase II Clinical Trial of Monkeypox Treatment by NV-387 is expected to begin soon in the Democratic Republic of Congo (DRC).

NanoViricides Seeks FDA Approval for First-Ever MPox Treatment as Cases Rise

Clinical Trial Site preparations are being performed by our CRO in India, Om Sai Clinical Research Pvt. Ltd., and associates in DRC. The CRO personnel are expected to visit the Site for final preparations and for staff training in the first week of April, 2026. Enrollment and dosing of patients is expected to begin after the staff training is completed.

The Company previously reported that it has received approval to start said Phase II Clinical Trial of NV-387 for the Treatment of MPox by the Regulatory Agency ACOREP of the Democratic Republic of Congo (DRC).

The Phase II clinical trial will evaluate safety and effectiveness of NV-387 for the treatment of patients with MPox disease caused by hMPXV infection.

MPox Clade I is endemic in DRC and all cases in the clinical trial are expected to be of the Clade I virus. The other prominent MPox virus, MPox Clade II is substantially less severe an infection than MPox Clade I.

"This is an important milestone in regulatory development of NV-387," said Anil R. Diwan, PhD, President and Executive Chairman of the Company.

MPox is an "Orphan Disease" in the USA. NanoViricides has applied to the US FDA for Orphan Drug Designation (ODD) of NV-387 for the treatment of MPox. This ODD, assuming it is granted, would enable several benefits including frequent meetings with FDA, waiver of certain FDA fees, certain R&D credits, as well as extension in exclusivity in marketing once approved.

These ODD benefits can have a positive economic impact for NanoViricides estimated in the range of tens of millions of dollars.

There is no drug available for the treatment of hMPXV infection that causes the MPox disease.

NV-387 would be the "go to" pandemic response candidate if it is successful in the Phase II MPox clinical trial. US Government SNS stockpiling contracts for existing smallpox drugs TPOXX and TEMBEXA have been in several hundreds of millions of dollars, representing an equivalent potential opportunity for NV-387.

MPox Clade II has become endemic in the USA, circulating at low levels. It primarily affects a limited population of Men-having-Sex-with-Men (MSM), because of transmission during sexual activity.

MPox Clade I cases in the USA have been slowly increasing. As of March 23, 2026, there have been 15 cases of MPox Clade I in the USA since November, '25, with 4 of them in March, '26, according to CDC.

Community spread of the MPXV Clade I is likely already occurring, with 3 cases of MPox Clade I with no travel to Africa, in California in unconnected persons, according to the CDC.

Thus MPox is becoming important in the USA from the perspective of pandemic preparedness and response. Although there is a vaccine originally developed for smallpox, namely, Jynneos, that is in use to prevent MPox (primarily in clade II contacts), its immune protection was found to wane rapidly in a clinical study. The effectiveness of this vaccine is limited, at 36% for one dose and 66% for 2 doses against the less pathogenic MPox Clade II.

The vaccine effectiveness is likely to be much less against the more severe MPox Clade I.

Vaccines do not protect in the first few weeks, limiting their usefulness during pandemic.

A clinical trial of tecovirimat (TPOXX, SIGA) failed to demonstrate any effectiveness over placebo, as per a NIH press release on August 15, 2024. Another drug, brincidofovir (TEMBEXA, EBS) entered into a clinical trial called "MOSA" with fanfare in January, 2025, with early topline results expected by the end of that quarter. The status of this clinical trial is not publicly known as of now. Previously, three MPox cases treated with TEMBEXA developed liver dysfunction. TEMBEXA carries a black-box warning, due to severe liver toxicity, entero-gastric toxicity, and requires clinical monitoring, making it unsuitable as a drug for pandemic response.

Thus both of the Smallpox drugs in the USA Strategic National Stockpile (SNS), TPOXX and TEMBEXA, would be unsuitable for pandemic response if MPox Clade I spreads, representing an opportunity for NV-387.

"NV-387, our broad-spectrum antiviral drug is poised to cause a revolution in treatment of viral diseases, just as antibiotics revolutionized the treatment of bacterial diseases," said Anil R. Diwan, Ph.D., adding "NV-387 is designed to mimic human cells to trap and destroy the virus. This single drug can target over 90-95% of human pathogenic viruses due to this biomimicry, which is reminiscent of the antibiotic penicillin that targets a large number of human pathogenic bacteria."

NV-387 was found to possess strong antiviral activity against an orthopoxvirus in an animal model that is considered an important model to establish potential effectiveness against MPox and Smallpox viruses, as all of these viruses belong to the same family of orthopoxviruses.

In fact, NV-387 effectiveness matched the effectiveness of the small chemical drug tecovirimat in two different models of infection, one was direct skin infection, and the other was a direct lung infection, by the virus.

Escape of virus from tecovirimat can occur by a single point mutation in a viral protein called VP-37. Vaccines, antibodies, and small chemical drugs such as tecovirimat for MPox/Smallpox, or oseltamivir (Tamiflu ), baloxavir (Xofluza ) for Influenza are readily escaped by viruses simply by introduction of small changes that viruses undergo when they are faced with these challenges in the field.

In contrast, escape of virus from NV-387 is highly unlikely because no matter how much the virus changes in the field, it continues to use sulfated proteoglycans such as HSPG as "attachment receptor" in order to cause cell infection. NV-387 mimics the sulfated proteoglycan signature feature that the viruses require.

NV-387 is a host-mimetic drug that "looks like a cell" to the virus, displaying numerous ligands that mimic the sulfated proteoglycan, enticing the virus to bind to and become engulfed by the NV-387 dynamic shape-shifting polymeric micelle.

Therefore development of NV-387, a broad-spectrum host-mimetic, direct-acting antiviral drug that the viruses cannot escape even as they change constantly, will be revolutionary once the drug undergoes regulatory development for approval for use in humans.

New viruses and existing viruses acquiring greater pathology and infectivity are bound to keep appearing in time. To combat such threats, we need to develop broad-spectrum drug arsenal that the viruses cannot escape. Vaccines and antibodies simply will not do, and their limitations have become clearly evident during the COVID-19 pandemic.