Efficacy and safety of preemptive anti-CMV therapy with valganciclovir after kidney transplantation

BACKGROUND: CMV infections still pose a potentially serious threat to kidney transplant recipients and have a significant impact on graft as well as patient survival. The antiviral agent valganciclovir (VGCV) has a greater bioavailability after oral administration than oral ganciclovir (GCV) and can be considered a substitute for GCV. The substance is approved in North America and Europe for anti-CMV prophylaxis after organ transplantation. In this pilot study, we examined if VGCV could also be administered in preemptive treatment of CMV infections. METHODS: Twenty-eight renal transplant recipients suffering from 32 asymptomatic episodes of CMV infection were treated with VGCV and followed up. CMV infection was diagnosed by routine controls of pp65-antigenemia in pre-defined intervals. All patients received sequential quadruple immunosuppression. VGCV was given for up to 12 wk in a dosage adapted to renal graft function. Efficacy and safety parameters were monitored for 16 wk. RESULTS: Twenty-seven episodes of CMV antigenemia, two patients progressing to CMV syndrome and three patients progressing to CMV disease were treated. Primary efficiency was 79%, Four patients relapsed and were treated with a second course resulting in serological recovery. Two patients did not respond to oral VCGV and were switched to another antiviral agent. Graft function remained stable during and after treatment. Serious side effects were seen in seven patients, four patients complained of diarrhea and gastrointestinal pain, three patients suffered from leucopenia, in one of these treatment had to be temporary paused. Fifty-nine percent of all episodes were treated in a completely ambulatory setting. CONCLUSIONS: VGCV can be considered as an option also for preemptive treatment of CMV infections after renal transplantation. The antiviral potency seems to be adequate, potential side effects are comparable with IV GCV. Because of the improved pharmacokinetics of VGCV the substance can be used to abbreviate or even completely avoid in-hospital care of CMV infections.