SP05 | MARIBAVIR AS ANTI-CYTOMEGALOVIRUS TREATMENT IN REFRACTORY OR RESISTANT DISEASES IN A NON-TRANSPLANT SETTING

Introduction: CMV infection can be life-threatening in immunocompromised patients. In the setting of allo-HSCT, different treatment strategies exist for refractory or resistant CMV disease. Otherwise, possibilities are not many in a non-transplant setting. Here we report two cases in which a first-line therapy was not enough in this setting. Case one: A 49-year-old woman was diagnosed with high-grade DLBCL. First CMV reactivation was observed during induction with R-DHAX; it was resolved with Valganciclovir. The DLBCL resulted refractory, so a second line therapy was started. She was not eligible for CAR-T because of lymphocytopenia. Second CMV reactivation occurred after R-IVAC and it was again resolved with Valganciclovir. Third reactivation occurred after R-CODOX-M; in this case it was resistant: she developed chorioretinitis and pancytopenia, and virus plasma load increased. Foscarnet was started as second-line, obtaining virus clearance. Soon after, CMV reactivated for the fourth time. We decided to start a third-line therapy with Maribavir, even if the drug is only indicated after HSCT. After two weeks, we obtained a complete response, permitting us to start a bridge therapy to HSCT with Glofitamab. After Maribavir stop, it was also started a prophylactic therapy with Letermovir. Unfortunately, soon after she died for an acute cardiac event, without developing any other CMV reactivation. Case two: A 35-year-old man was diagnosed with Hairy-Cell Leukemia (HCL), showing severe pancytopenia, fever and primary infection by CMV. Ganciclovir therapy was started and despite a clinical improvement, after 3 weeks CMV was still detectable. Because of the persistent pancytopenic state and the need to start chemotherapy, it was decided for a second-line therapy with Maribavir and, as in the previous case, it was obtained a complete response in 2 weeks. That permitted us to start the anti-HCL therapy with 2-CDA, after which the patient experienced pancytopenia with two bacterial complications, but no CMV positivity was anymore detected even after Maribavir stop. Conclusions: In our knowledge, these are the first cases in which Maribavir is used for CMV disease in a non-transplant setting. In both cases we obtained a long lasting virus clearance after two weeks of treatment. Further evaluations are needed, but from these first datas we can speculate about the possibility to extend the use of Maribavir also in immunocompromised not-transplanted patients.