Cytomegalovirus (CMV) is a major contributor to morbidity and mortality in solid organ transplant recipients (SOTRs). Ganciclovir and valganciclovir are highly effective antiviral drugs with a well-established role in primary prophylaxis and treatment of CMV disease. Our objective in this study was to examine the effect of secondary prophylaxis (SP) on the risk of relapse in SOTRs following an episode of CMV disease.

We performed a retrospective cohort study of SOTRs from 1995 to 2015 and used propensity score-based inverse probability of treatment weighting methodology to control for confounding by indication. A weighted Cox model was created to determine the effect of SP on time to relapse within 1 year of treatment completion.

Fifty-two heart, 34 liver, 79 kidney, and 5 liver-kidney transplant recipients who completed treatment for an episode of CMV infection/disease were included. A total of 120 (70.6%) received SP (median duration, 61 days; range, 5-365) and 39 (23%) relapsed. SP was protective against relapse from 0 to 6 weeks following treatment completion (hazard ratio [HR], 0.19; 95% confidence interval [CI], 0.05-0.69). However, after 6 weeks, risk of relapse did not significantly differ between the 2 groups (HR, 1.18; 95% CI, 0.46-2.99).

Our findings demonstrate that use of SP following treatment of CMV disease did not confer long-term protection against relapse, although it did delay relapse while patients were receiving antivirals. This suggests that SP has limited clinical utility in the overall prevention of recurrent CMV disease.