Valganciclovir as Add-on to Second Line Therapy in Patients with Recurrent Glioblastoma

Abstract IntroductionGlioblastoma invariably recurs despite aggressive and multimodal first line treatment and no standardized second line therapy exists. We previously reported that treatment with the antiviral drug valganciclovir as an add-on to standard therapy significantly prolonged overall survival in 102 patients with newly diagnosed glioblastoma. Here we present the results of retrospective survival analyses including patients with glioblastoma that initiated valganciclovir therapy after recurrence. MethodsBetween April 13, 2007 and March 31, 2021, 29 patients with recurrent glioblastoma received valganciclovir as an add-on to second line therapy. Contemporary controls were 111 patients with glioblastoma who received similar second line therapy at our institution. We retrospectively analyzed survival data of these patients. ResultsPatients with recurrent glioblastoma who received valganciclovir had longer median overall survival after recurrence than controls (12.1 vs 7.4 months, respectively, p=0.0017). The drug was well tolerated. Both patients who underwent re-operation and patients that were not re-operated after recurrence benefitted significantly from valganciclovir therapy. Valganciclovir prolonged survival after recurrence both in patients with an unmethylated or methylated MGMT promoter gene. ConclusionValganciclovir was safe to use and prolonged median survival after recurrence of patients with recurrent glioblastoma, re-operated or not after recurrence and with methylated or unmethylated MGMT promoter gene.