Preclinical evaluation of Brincidofovir in glioblastoma demonstrates improved long term-survival and cytomegalovirus-dependent and independent effects

Cytomegalovirus (CMV) has been implicated in glioblastoma (GBM) progression. Ongoing clinical trials are assessing therapeutic approaches targeting CMV in GBM but to date no new therapy has been approved outside the standard of care. Previous preclinical studies have highlighted the potential of the antiviral drug Cidofovir (CDV) in GBM; however, its clinical use is limited by dose-dependent nephrotoxicity and poor cellular uptake, necessitating high intravenous doses to achieve therapeutic activity. Brincidofovir (BCV), a lipid conjugate of CDV has been developed, which does not induce nephrotoxicity and has significantly greater cellular bioavailability. Here we examined the effects of BCV in a newly established CMV-driven GBM model (SB28) and in patient-derived tumor neurospheres. We show that BCV prolongs survival in vivo and exerts both CMV-dependent and independent antitumor effects. Mechanistically, BCV induces DNA damage and cell cycle dysregulation in GBM cells and inhibits proliferation of patient-derived neurospheres in a dose-dependent manner. These data identify BCV as a dual-action therapeutic that suppresses viral oncomodulation while directly targeting tumor cell viability.