Standard-versus low-dose valganciclovir for cytomegalovirus prophylaxis in intermediate-risk kidney transplant recipients

Background: Although guidelines recommend valganciclovir (VGC) 900 mg daily for cytomegalovirus (CMV) prophylaxis in solid organ transplant patients, multiple centers have reported clinical success, reduced side effects, and cost savings using VGC 450 mg daily. Methods: This single-center, retrospective cohort study compared the efficacy and safety of renally-adjusted VGC 900 mg versus 450 mg daily for 6 months for CMV prophylaxis in intermediate-risk kidney transplant recipients. Patients were divided into low- and standard-dose groups based on institution protocol according to their creatinine clearance and VGC dose. Adult patients were included if they were seropositive for CMV and received a kidney transplant from January 1st, 2014 to November 30th, 2016. Patients were excluded if they received multi-organ transplant (except kidney-pancreas) or did not follow up at the study institution. Data was collected for 1 year post-transplant. The primary outcome was CMV disease, defined as requiring treatment for CMV. Secondary outcomes include: neutropenia, treatment of rejection, ganciclovir-resistant infection, and graft loss. Severe neutropenia was defined as absolute neutrophil count below 500/mm3 on any 2 readings while on VGC. Results: A total of 143 intermediate-risk patients were included: 61 patients in the low-dose group (VCG 450 mg daily) and 82 patients in the standard-dose group (VCG 900 mg daily). The average age of patients was 52.3 and 55.5 years in the low-dose and standard-dose group, respectively. The majority of patients received anti-thymocyte globulin for induction (n=111, 77.6%). CMV disease occurred in 5 patients in the low-dose group vs 9 in the standard-dose group (8.2% vs 11.0%; p=0.58; OR 1.38, 95% CI 0.44-4.35). Of the 14 patients who developed CMV, 13 received anti-thymocyte globulin and 1 received basiliximab for induction. Severe neutropenia occurred in 6 patients in the low-dose group versus 2 patients in the standard-dose group. Graft loss occurred in 1 patient in the low-dose group. No patients had ganciclovir resistant infection. Conclusions: Rates of CMV disease, hematologic events, ganciclovir-resistance, and graft loss were similar among intermediate-risk patients who received renallyadjusted VGC 900 mg and VGC 450 mg for CMV prophylaxis post-kidney transplant. These findings suggest the use of VGC 450 mg is a safe and effective option for CMV prophylaxis in intermediate-risk kidney transplant recipients