Valganciclovir is an orally administered prodrug that is rapidly hydrolyzed to ganciclovir. We compared the effects of oral valganciclovir with those of intravenous ganciclovir as induction therapy for newly diagnosed cytomegalovirus retinitis in 160 patients with the acquired immunodeficiency syndrome (AIDS).

The primary end point was photographically determined progression of cytomegalovirus retinitis within four weeks after the initiation of treatment. Secondary end points included the achievement of a prospectively defined satisfactory response to induction therapy and the time to progression of cytomegalovirus retinitis. After four weeks, all patients received valganciclovir as maintenance therapy.

Eighty patients were randomly assigned to each treatment group. Of the patients who could be evaluated, 7 of 70 assigned to intravenous ganciclovir (10.0 percent) and 7 of 71 assigned to oral valganciclovir (9.9 percent) had progression of cytomegalovirus retinitis during the first four weeks (difference in proportions, 0.1 percentage point; 95 percent confidence interval, –9.7 to 10.0). Forty-seven of 61 patients (77.0 percent) assigned to intravenous ganciclovir and 46 of 64 (71.9 percent) assigned to valganciclovir had a satisfactory response to induction therapy (difference in proportions, 5.2 percentage points; 95 percent confidence interval, –20.4 to 10.1). The median times to progression of retinitis were 125 days in the group assigned to intravenous ganciclovir and 160 days in the group assigned to oral valganciclovir. The mean values for the area under the curve for the ganciclovir dosage interval were similar at both induction doses and maintenance doses. The frequency and severity of adverse events were similar in the two treatment groups.

Orally administered valganciclovir appears to be as effective as intravenous ganciclovir for induction treatment and is convenient and effective for the long-term management of cytomegalovirus retinitis in patients with AIDS.