Successful treatment and durable remission of human herpesvirus‐8‐induced Kaposi sarcoma and multicentric Castleman's disease under valganciclovir in an HIV ‐negative patient

Abstract

Dear Editor, Kaposi sarcoma (KS) is an angiogenic proliferative disease that is associated with a human herpesvirus-8 (HHV-8) infection. 1 HHV-8 is an oncogenic virus, also associated with other conditions, such as primary effusion lymphoma or multicentric Castleman's disease (MCD). 1 So far, the role of antivirals in the management of HHV-8-induced KS is not fully explored. In this study, we present the administration of adjuvant long-term valganciclovir as a potential therapeutic option for the treatment of KS.

Primary Effusion Lymphoma, Multicentric Castleman’s Disease, and Kaposi’s Sarcoma in an HHV-8 and HIV-Positive Patient: A Case Report

“…Even though, in our case, it was not possible to quantitatively measure the patient’s viremia, there are documented reports indicating that antiviral therapy can reduce viral replication and even achieve MCD remission [ 30 , 31 ]. Recently, an increasing number of reports suggest the use of this antiviral in patients with these types of HHV-8-related diseases [ 32 ]. Although its use in monotherapy seems to have no clear efficacy, the latest expert recommendations suggest that its use in combination with the immunochemotherapy regimen and probably as maintenance may improve outcomes [ 33 ].…”

Therapeutic Perspectives in the Systemic Treatment of Kaposi’s Sarcoma

“…The clinical efficacy of antivirals in KS and HHV-8-associated diseases has been only tested in case reports or small series, generally in combination with initial chemotherapy [43,55]. The efficacy of (val)GCV or Fos on HHV-8-viral load has been suggested by the clinical improvement induced by (val)GCV or CDV or Fos, or by the maintenance of remission achieved with (val)GCV [35,43,[55][56][57][58][59].…”

“…The clinical efficacy of antivirals in KS and HHV-8-associated diseases has been only tested in case reports or small series, generally in combination with initial chemotherapy [43,55]. The efficacy of (val)GCV or Fos on HHV-8-viral load has been suggested by the clinical improvement induced by (val)GCV or CDV or Fos, or by the maintenance of remission achieved with (val)GCV [35,43,[55][56][57][58][59]. In a randomized cross-over clinical trial testing a daily dose of 900 mg of valganciclovir versus placebo, Casper et al found a significant reduction in the frequency and quantity of HHV-8 replication in 26 HHV-8-infected men [44].…”

Recent Advances in Developing Treatments of Kaposi’s Sarcoma Herpesvirus-Related Diseases

“…In patients, some studies reported ganciclovir, valganciclovir, valacyclovir, famciclovir, cidofovir or foscarnet to reduce the shedding of KSHV in oral samples or KSHV viral load in peripheral blood, while others failed to notice pronounced effects of these drugs in treated patients [41][42][43]. With few exceptions [44], herpesviral DNA polymerase inhibitors (foscarnet, cidofovir, ganciclovir, valganciclovir) were found to be largely ineffective when used to treat established KS lesions [45][46][47][48]. In addition to these drugs, which are already approved for clinical use against other herpesviruses, several new promising nucleoside inhibitors have been identified in preclinical studies but are not yet approved or available for clinical treatments (for more details, see: [37,40,[49][50][51].…”