Inhibiting varicella-zoster
NanoViricides drug candidates reduce extent of shingles virus infection of human skin
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SHELTON, Conn.—NanoViricides Inc., a development-stage company creating special-purpose nanomaterials for antiviral therapy, has reported that its anti-shingles nanoviricides drug candidates have achieved dramatic reduction in infection of human skin by the varicella-zoster virus (VZV), the shingles virus. The company’s novel nanoviricide class of drug candidates are designed to specifically attack enveloped virus particles and dismantle them.
These findings corroborate the previously reported findings of inhibition of VZV infection of human cells in culture. VZV is restricted to human tissue and only infects and replicates in human tissue.
Over the time course of VZV infection, the nanoviricides drug candidates showed marked inhibition of VZV infection, replication and spread in human skin cultured ex vivo. The data suggest that select nanoviricides drug candidates may have direct viricidal activity based on their antiviral effects within the first 24 hours after viral infection.
The antiviral effect of certain nanoviricide drug candidates was substantially greater than the effect of the standard positive control of cidofovir added into media. The effect of these drug candidates was equivalent to a topical formulation of 1 percent cidofovir applied directly onto the skin patch. A topical skin cream containing 2 percent cidofovir is clinically used in very severe cases of shingles. However, the cytotoxicity of cidofovir is known to cause ulceration of the skin to which it is applied, followed by natural wound healing.
Because VZV causes skin lesions because of direct attack of the reawakened virus released from nerve endings onto the human skin cells, this ex-vivo human skin patch model involving VZV infection of cultured human skin ex vivo is considered to be a close representation of natural course of shingles.
NanoViricides previously reported that these same nanoviricides compounds displayed potent inhibition of VZV infection of a human retinal epithelial pigment cell line in an in-vitro cell culture virus infection model with no evidence of toxicity to the cells. These ex-vivo and in-vitro studies are a critical step in the selection of final clinical drug development candidates for safety and toxicology studies with the goal of an IND submission to the FDA for the topical treatment of shingles in humans.
According to Dr. Eugene Seymour, CEO of NanoViricides, “These human skin studies provide important validation of our VZV project and will expedite our VZV drug development as well as our entire herpicide drug program.”
He added, “Nanoviricides inhibit VZV infection, replication and spread by directly destroying the virus on contact. They would be administered by intravenous, oral, topical, eye drops, intravitreal injection.”
The human skin studies were performed in the laboratory of Dr. Jennifer Moffat at SUNY Upstate Medical University. The National Institutes of Health (NIH) has a contract with Moffat’s lab for evaluating anti-viral compounds against VZV, although NanoViricides chose to set up a direct collaboration with Moffat rather than going through the NIH program. The final herpes compound decision will rest with the work done in Moffat’s laboratory, Seymour explained.
According to Moffat, “The nanoviricides compounds we tested in the skin assays showed clear evidence of anti-VZV activity. We are pleased that our results can be used to select the most promising compounds.”
NanoViricides intends to produce the quantities of its drug candidates necessary for all drug development activities, including safety and toxicology and initial human clinical trials, at its current facility. The company has continued to optimize the cost and time efficiency of its manufacturing processes for the ligands, polymers and final ligand-polymer nanoviricides drug candidates. It is developing drugs against a number of viral diseases, including VZV, oral and genital herpes, viral diseases of the eye including epidemic keratoconjunctivitis and herpes keratitis, H1N1 swine flu, H5N1 bird flu, seasonal influenza, HIV, hepatitis C, rabies, dengue fever and Ebola virus, among others.
“VZV is the chicken pox virus, and virtually everyone is harboring the virus in their body,” Seymour said. “There are approximately one million cases of shingles in the U.S. every year. Besides the pain of the infection itself, there is a complication that appears in 75 percent of those over 65. There are approximately 500,000 cases of this complication in the U.S.”
He added, “I’ve treated many patients with this complication and the pain is often unresponsive to morphine. It’s defined as pain that starts after clearing of the initial lesions, and it’s called post-herpetic neuralgia. It is a non-infectious immune response to the shingles outbreak. It’s one of the more common causes of suicide in the affected elderly. I feel that early treatment with our topical gel with prevent the development of this complication, but this has to be tested in our human trials next year.”