Maribavir as good as valganciclovir for cytomegalovirus infection in transplant recipients

Maribavir 400 mg twice daily appears to have comparable efficacy to valganciclovir at clearing cytomegalovirus (CMV) viraemia in transplant recipients, a study has found.

The phase II, open-label trial randomized 161 recipients of haematopoietic-cell or solid-organ transplants with CMV reactivation (1,000 to 100,000 DNA copies per millilitre) to receive maribavir at a dose of 400, 800 or 1,200 mg twice daily or the standard dose of valganciclovir for no more than 12 weeks.

Of the patients, 159 received treatment and 156 had postbaseline data available (117 in the maribavir groups and 39 in the valganciclovir group). Response to treatment within 3 weeks occurred in 62 percent of patients in the combined maribavir groups and 56 percent in the valganciclovir group. Within 6 weeks of treatment, 79 percent and 67 percent of patients had a response (risk ratio, 1.20, 95 percent confidence interval, 0.95–1.51). Treatment response did not differ among the maribavir dose groups.

CMV infection recurred within 6 weeks in two patients who received maribavir at a dose of 800 mg twice daily. Both patients developed T409M resistance mutations in CMV UL97 protein kinase.

Serious adverse events that occurred or worsened during treatment were higher in the maribavir group than in the valganciclovir group (44 percent vs 32 percent). Adverse events leading to trial discontinuation also occurred with greater frequency in the former (23 percent vs 12 percent). Gastrointestinal adverse events were common with maribavir, whereas neutropaenia was reported more frequently with valganciclovir.

Maribavir, especially given its unique mechanism of action and evidence suggesting a lack of myelosuppression, should be explored further in patients who have undergone transplantation, according to the researchers.