Pilot study of oral valganciclovir therapy in patients with classic Kaposi sarcoma.

We conducted a clinical trial of oral valganciclovir, a drug with in vitro activity against Kaposi sarcoma (KS)-associated herpesvirus (KSHV), in classic KS. Five human immunodeficiency virus-seronegative participants received valganciclovir for up to six 4-week cycles at doses used for cytomegalovirus infection. None of the study subjects showed an objective response; KS progressed in 4 subjects after 1-4 cycles and remained stable in 1 subject after 6 cycles. KS biopsies showed minimal lytic KSHV antigen and gene expression at baseline and no treatment-associated changes. Although valganciclovir was not active against KS in this setting, other appropriately targeted anti-herpesviral strategies may prove to be more effective.