An Interventional Study of Letermovir for Secondary Prophylaxis After Treatment of Cytomegalovirus Infection in High Risk (D+/R-) Kidney and Kidney/Pancreas Transplant Recipients

Study Population: Patients over 18 years of age who have undergone kidney or simultaneous kidney/pancreas transplant and are high-risk CMV serostatus (D+/R-) at time of transplant who develop CMV viremia that necessitates treatment per our institutional protocol (enrolled in our CMV stewardship monitoring initiative) and demonstrate proven or presumptive lack of cell-mediated immunity, either by CMI testing or risk factor screening.

Patients will be converted from treatment with ganciclovir derivatives to letermovir (480 mg tablet taken orally once daily) when the viral load via standard of care (SOC) weekly monitoring is < 500 IU/mL. This differs from SOC which only allows conversion to secondary prophylactic treatment after CMV is no longer detected on polymerase chain reaction (PCR) for 2 consecutive weeks. Thus, liberalization of conversion threshold will allow for reduced exposure to valganciclovir via reduced duration of therapy allowing relief of the myelosuppressive toxicity and creates an environment conducive to cell-mediated immunity (CMI).

The primary objective is to assess the efficacy of letermovir as secondary prophylaxis after treatment of CMV infection.

The secondary objective is to detect the development of cytomegalovirus-specific cell-mediated immunity as determined by a positive result using the Eurofins-Viracor CMV inSIGHTTM T Cell Immunity Testing per manufacturer specifications.