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Shingles and Varicella Zoster Virus (VZV) |
Over 90% of the adult population is chronically infected with Varicella
Zoster Virus (a form of herpesvirus also known as "VZV").
Initial exposure to the virus takes place during childhood where VZV infection is
identified as “Chickenpox”. Despite the resolution of clinical symptoms,
very few infected individuals clear the virus, and the virus is harbored
latently in neural tissue called ganglia. VZV lies dormant in the
ganglia where it remains well-controlled by the immune system. However, when VZV reactivation occurs, “Shingles” develops.
An estimated 5 in 1000 people suffer from shingles in the US every year,
and 20% of all individuals are estimated to experience at least one
episode of shingles during their lifetime. The risk of shingles outbreak dramatically increases with age. With the
growing population of individuals over the age of 60 dominated by the
“Baby Boomers,” the number of shingles cases is expected to increase
significantly over the next decade.
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Shingles manifests itself as a rash that begins as red patches that soon
develop into blisters, often mainly on one side of the body. The
blisters may remain small but can grow substantially in size. The normal
healing process takes about four weeks, with potential scarring as one
long term effect.
Shingles is often extremely painful. The pain is frequently
observed as zoster associated pain (ZAP) and post-herpetic neuralgia (PHN). ZAP is
present during the initial disease outbreak. During this period of
dermal eruptions, pain is common and may persist after the resolution of
lesions. ZAP is a major contributor to morbidity in zoster.
PHN is a persistent pain that is present long after
the lesions have resolved. The pain can persist for months and sometimes
years. The pain associated with PHN does not respond well to traditional
analgesic treatment and remains a major unmet need in shingles. |
Valomaciclovir (EPB-348) and Shingles
Valomaciclovir has
demonstrated excellent in vitro and in vivo anti-viral activity against
VZV. A Phase 2b study in patients with acute shingles to examine the
safety and efficacy of once-daily dosed Valomaciclovir compared to an
active comparator dosed three-times daily has been successfully completed. |
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