Maribavir for cytomegalovirus retinitis: A case series and review of the literature

Therapy for vision-threatening CMV retinitis is often limited by drug resistance or systemic toxicity. Maribavir, a novel UL97 kinase inhibitor that has been FDA-approved for refractory CMV viremia, is a potential alternative to traditional antiviral therapy but remains understudied for CMV retinitis. The objective of this series is to describe the clinical courses and outcomes of patients with CMV retinitis after initiation of maribavir therapy. Retrospective case series. Six patients (11 eyes) with CMV retinitis from two tertiary uveitis centers. All were immunocompromised due to chemotherapy, immunotherapy, or AIDS and were initially treated with standard therapy (systemic and/or intravitreal ganciclovir, valganciclovir, or foscarnet) before developing drug resistance, toxicity, or intolerance prompting a transition to maribavir as alternative therapy. Oral maribavir 400mg twice daily. Time to retinitis quiescence, visual acuity (VA), and adverse effects of therapy. 4/11 eyes had active retinitis upon initiation of maribavir and all achieved quiescence within 6 weeks. The remaining 7/11 eyes were already quiescent and remained so. VA remained stable or improved in all eyes. Notable clinical courses included (1) rapid decline in aqueous CMV titer and resolution of retinitis in a patient with multidrug-resistant CMV failing intravitreal ganciclovir/foscarnet; (2) a patient with UL54-resistant CMV and bilateral macula-involving retinitis rapidly achieving inactivity and preserved visual acuity on maribavir; and (3) successful substitution of maribavir in patients who were unable to continue conventional antiviral therapy due to drug-induced neutropenia or nephrotoxicity. Maribavir was generally well-tolerated, and only mild adverse effects were reported (dysgeusia, myalgia). Review of the literature identified 2 additional cases of patients with similar clinical courses achieving resolution of retinitis on maribavir. In this descriptive case series, patients with multidrug-resistant CMV retinitis or intolerance to traditional antiviral therapy were observed to achieve or maintain quiescence of retinitis following initiation of maribavir. These findings suggest maribavir as a potential novel systemic option for challenging cases of CMV retinitis. Prospective studies are necessary to further characterize the efficacy and safety of maribavir for the treatment of CMV retinitis, as well as optimal duration of therapy after quiescence.