The imidazoquinoline, imiquimod, is a low molecular weight, synthetic immun
e response modifier that is used for the treatment of external genital and
perianal warts. It is formulated in a 5% vanishing cream as Aldara(R). This
self-applied therapy has shown good efficacy and safety in the treatment o
f external genital and perianal warts caused by human papillomavirus (HPV)
infection. The antiviral mechanism of action of this compound is unlike any
other approved antiviral therapy in that it induces the production of anti
viral cytokines and cytokines that enhance cellular immunity believed to be
necessary for the control or elimination of HPV infection. Imiquimod does
not exert its antiviral effects directly on virus-infected cells. Treatment
with imiquimod results in resolution of wart tissue and reduction of viral
burden. Postmarketing trials using imiquimod demonstrated that patients wh
o experience complete clearance of either new or recalcitrant warts tend to
remain clear for longer periods as compared to other treatment modalities.
Preclinical data demonstrate in vitro and in vivo that imiquimod directly
induces antiviral and immunomodulating cytokines from monocytes, macrophage
s and dendritic cells. These immunomodulating cytokines have been shown to
potentiate Th1 immunity. Self-application, good tolerability, a unique mech
anism pf action and a relatively high sustained clearance rate combine to m
ake imiquimod a cost-effective first-line therapy for external genital wart
s and an appropriate second-line therapy when other treatments are unsucces
sful. In small-scale studies requiring replication, imiquimod has also been
shown to be effective in the treatment of non-HVP-related skin infections
and some dermal neoplasias. (C) 1999 Prous Science. All rights reserved.