Impact of kidney function on 200 days of antiviral prophylaxis for cytomegalovirus disease in cytomegalovirus-seronegative recipients of cytomegalovirus-seropositive donor kidneys: Post hoc analysis of a randomized, phase 3 trial of letermovir vs valganciclovir prophylaxis.

This post hoc analysis was conducted to understand the impact of kidney function on 200 days of cytomegalovirus (CMV) prophylaxis in CMV donor-positive/recipient-negative (D+R-) kidney transplant recipients (KTRs). Adult CMV D+R- KTRs were randomized (1:1) posttransplant to letermovir 480 mg (with acyclovir and valganciclovir placebo) or valganciclovir 900 mg (with acyclovir and letermovir placebos) daily for 28 weeks (NCT03443869). Valganciclovir and acyclovir doses were modified for kidney function (Cockcroft-Gault creatinine clearance [CrCl]). Dose frequency, adherence, CMV DNAemia, and discontinuations were evaluated at week 28. A total of 480 CMV D+R- KTRs had a median CrCl of 67 mL/min. All participants taking letermovir (or letermovir placebo) received daily dosing (ie, no intermittent dosing), whereas approximately 50% of participants receiving valganciclovir (or valganciclovir placebo) received intermittent dosing (ie, every 2 days or twice weekly titrated to CrCl). Kidney function did not impact adherence, quantifiable CMV DNAemia, or prophylaxis discontinuation in the letermovir group; however, adherence was lower, and quantifiable CMV DNAemia and discontinuation occurred more frequently in the valganciclovir group, particularly among those with lower kidney function posttransplant. In CMV D+R- KTRs, letermovir prophylaxis was associated with less CMV DNAemia compared with valganciclovir in participants with low kidney function during the 200-day prophylaxis period.