Adenovirus infections of immunocompromised patients can develop into deadly multiorgan or systemic disease. The virus is especially threatening for pediatric allogeneic hematopoietic stem cell transplant recipients; according to some studies, 10% or more of these patients succumb to disease resulting from
adenovirus infection. At present, there is no
drug approved for the treatment or prevention of
adenovirus infections. Compounds that are approved to treat other
virus infections are used off-label to combat adenovirus, but only anecdotal evidence of the efficacy of these drugs exists.
Ganciclovir, a
drug approved for the treatment of
herpesvirus infection, was previously reported to be effective against human adenoviruses in vitro. To model
adenovirus infections in immunocompromised humans, we examined
ganciclovir's efficacy in immunosuppressed Syrian hamsters intravenously infected with type 5 human adenovirus (Ad5). This animal model is permissive for Ad5 replication, and the animals develop symptoms similar to those seen in humans. We demonstrate that
ganciclovir suppresses Ad5 replication in the liver of infected hamsters and that it mitigates the consequences of Ad5
infections in these animals when administered prophylactically or therapeutically. We show that
ganciclovir inhibits Ad5
DNA synthesis and late gene expression. The mechanism of action for the
drug is not clear; preliminary data suggest that it exerts its antiadenoviral effect by directly inhibiting the adenoviral
DNA polymerase. While more extensive studies are required, we believe that
ganciclovir is a promising
drug candidate to treat
adenovirus infections.
Brincidofovir, a
drug with proven activity against Ad5, was used as a positive control in the prophylactic experiment.