Single Arm Pilot Trial of Letermovir for CMV Prophy in CAR T Cell

The goal of this clinical research study is to learn if a drug called Letermovir can help to prevent CMV reactivation.

Primary Objective: Estimate the probabilities at days d = +28 and +98 following CAR T cell infusion, among patients alive at the day of evaluation, of CMV reactivation in CMV seropositive patients receiving letermovir for CMV prophylaxis after standard of care (SOC) axicabtagene ciloleucel (AXI-CEL) therapy, using the cutoff CMV DNA qPCR \> c for c = 400 and 1000 IU/mL to define CMV reactivation, for a total of four (d, c) combinations. Secondary Objectives: Estimate overall survival probabilities at days+28, +98, and +364 following CAR T cell infusion of CMV seropositive patients receiving letermovir for CMV prophylaxis after SOC AXI-CEL therapy. Describe the tolerability of letermovir during the period of CMV prophylaxis after SOC AXI-CEL therapy in CMV seropositive patients at high risk for CMV reactivation.