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Herpetic
keratitis is the leading cause of corneal blindness in
industrialized nations. It is an increasingly significant
problem in developing nations as well. Of the estimated
50,000 cases reported annually in the U.S.,
about 50% are estimated to be recurrent cases. Recurrent
infections are more likely to invade the corneal stroma and
cause scarring and loss of vision. Stromal manifestations
appear in approximately 25% of recurrences. Whereas the
epithelial form of the disease is a direct result of the
viral infection itself, stromal keratitis appears to be a
largely immune-mediated disease.
Commonly
used therapeutic agents for herpetic keratitis are
nucleoside and nucleotide analog antivirals, which are
generally used topically. Despite their utility in
epithelial disease, none of these topical agents can
ameliorate stromal keratitis. For this form of the disease a
topical steroid, such as prednisolone, is prescribed. The
use of immuno-suppressants often results in resurgence of
latent virus. With some of these agents, prolonged use is
associated with ocular toxicity, such as superficial
punctuate keratitis and irritation. In addition to the
problems associated with antiviral agents, serious side
effects are associated with ocular steroid use. These
include development of opportunistic microbial infections,
suppression of corneal wound healing, and steroid-induced
glaucoma and cataract formation. Furthermore, viral
resistance to antiviral drugs is known to occur and is
especially threatening to immuno-compromised patients.
Redox
Pharmaceutical Corporation has developed Doxovir™ as a
topical treatment for Herpes Virus infection, Adenovirus
infections and other viral and inflammatory diseases of the
eye. Doxovir™ is well suited for the treatment of such disorders because
unlike available therapies, which frequently require the use
of corticosteroids to treat inflammation, Doxovir™ is active
against both the viral infection and inflammation. The
anti-inflammatory component of Doxovir™ is non-steroidal and
does not have the negative complications associated with
steroidal therapy.
The FDA
has approved Doxovir™ as an Investigational New Drug
for ophthalmic Herpes application. Redox Pharmaceutical
Corporation has successfully concluded Phase I clinical trials for this application. Phase II clinical trials are being performed.
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