SHELTON, CONNECTICUT -- Tuesday, August 7, 23, 2018 -- NanoViricides, Inc. (NYSE MKT: NNVC) (the "Company") reports that its anti-Shingles drug candidates were effective in ameliorating pain sensations in an animal model of abnormal pain. A characteristic excruciating pain is a debilitating pathology of shingles presentation. Thus a direct pain-reducing effect of the Company's anti-shingles drug candidates would be very important in ameliorating the pathology of shingles, in addition to the already demonstrated significant antiviral effect.
More importantly, the characteristic pins-and-needles pain in shingles can persist in some patients even after the shingles dermal presentation has resolved, for six months or longer. This is called "post-herpetic neuralgia (PHN)" and is a debilitating complication of shingles.
A highly effective treatment of shingles that would result in reduction in the duration and severity of PHN cases has been estimated to have a potential market size in the range of billions of dollars, even after the recent introduction of the new Shingrix vaccine. Approximately 18% of patients overall, and as many as 30-50% of older patients with shingles, are estimated to have PHN. This represents more than 200,000 cases of PHN annually in the USA alone. Such VZV complications can cause extended hospitalization in about 4% of shingles patients overall, with an average estimated cost as high as $20,000 per hospitalized patient.
Shingles is caused by reactivation of the Varicella Zoster Virus (VZV, aka human herpesvirus-3 or HHV-3). A chickenpox (i.e. varicella) infection in childhood leads to the virus becoming latent in the nervous system. At an older age, or when immunity against this resident latent virus decreases, the virus replicates in the nerve cells, and bursts out of the nerve endings infecting neighboring skin cells, thus causing a typical shingles rash. The nerve injury caused by the virus leads to a characteristic excruciating and debilitating pain. The shingles rash may continue to expand for several days, and then subsides in about three weeks in an uncomplicated case. The VZV-associated neuropathic pain does not resolve quickly, and may continue even after the rash has resolved (hence called PHN), for several months to, in rare cases, years.
Nerve injury of the peripheral sensory system due to trauma or disease sometimes produces abnormal (neuropathic) pain. This type of nerve injury and abnormal pain sensations are often observed in patients with shingles caused by reactivation of the varicella zoster virus (VZV) as well as in other diseases caused by herpes virus infections.
In the current animal study, topical treatment with the nanoviricides® anti-VZV compounds significantly reduced the measures of abnormal pain sensations in a rat model of neuropathic pain. The study was conducted at AR Biosystems in Tampa FL.
This effect is important for human neuropathic pain and for PHN. Firstly, this effect indicates that the Company's anti-shingles drug candidate could ameliorate the shingles-associated pain. This is a highly sought-after characteristic for an anti-shingles drug. Secondly, it could reduce the severity of PHN, and the drug could be used even after the rash has subsided to minimize the residual PHN. This could lead to a reduction in the need for traditional pain killers, which is an important benefit.
These results complement the positive findings in a model of VZV (the shingles virus) infection of human skin in which its shingles virus drug candidates demonstrated highly effective anti-VZV activity. In addition, no safety or toxicology concerns have been observed in a preliminary safety/toxicology animal study.
The results of this study and other pre-clinical studies of virus infection will provide the basis for selection of a final drug development candidate.
The Company is now planning IND-enabling safety/toxicology studies. In addition, the Company is also scaling up its production capabilities for these drug candidates, to support the ensuing safety/toxicology studies and initial human clinical trials.
Currently there is no effective therapy for shingles or for PHN. While acyclovir derivatives may be prescribed for shingles, acyclovir does not have a significant antiviral effect against VZV. PHN is treated with escalating levels of traditional pain medications, beginning with NSAIDs, and progressing to morphine-class of drugs depending upon severity and length of the episode. An older shingles vaccine is not very effective in protecting older patients. However, a new vaccine, Shingrix™, was introduced recently that is expected to be very effective. In spite of these vaccines, a drug for the treatment of VZV-shingles remains a sought-after unmet medical need, and presents a potential multi-billion dollar market.
About NanoViricidesFDA refers to US Food and Drug Administration. EMA refers to the European Union’s office of European Medical Agency.