Transplant Trial Watch

Valacyclovir or valganciclovir for cytomegalovirus prophylaxis: A randomized controlled trial in adult and pediatric kidney transplant recipients.

Verghese, P. S., et al.

Journal of Clinical Virology 2024; 172: 105678.

This study aimed to compare the safety, tolerability and effectiveness twice daily valacyclovir (valA) compared to valganciclovir (valG) for cytomegalovirus (CMV) prophylaxis following kidney transplantation.

Participants were randomised to receive either valA or valG.

140 adult and paediatric kidney transplant recipients.

The primary endpoint was the incidence, magnitude, and duration of CMV viremia or disease. The secondary endpoints were antiviral prophylaxis dose reduction or cessation because of adverse drug side effects, and the incidence, magnitude, and duration of Epstein-Barr virus (EBV) viremia.

6 months following antiviral prophylaxis.

CET Conclusions
This is an interesting phase 2 trial of CMV prophylaxis for patients after kidney transplantation. The sample size is typical for a phase 2 study and the primary outcome was CMV viraemia, but there is a focus on side effects of the medications. The incidence of CMV viraemia was similar in the two groups, but in a larger study may have shown a significant difference. Patients in the valganciclovir group were much more likely to need a dose-reduction due to side effects, most commonly leukopenia, which is an objective outcome and therefore not as subject to bias as subjective outcomes in an open-label study such as this. In its favour, the study analysis is by intention-to-treat. The inclusion of low-risk patients (donor negative, recipient negative) in this study abrogates the potential magnitude of any difference in CMV viraemia risk. A larger, blinded trial is required to adequately compare the two medications. This would require large numbers due to the absolute risk of CMV viraemia being low. It would be possible in a multicentre study.

Jadad score

Data analysis
Modified intention-to-treat analysis

Allocation concealment

Trial registration - NCT01329185

Funding source
Non-industry funded