SAN FRANCISCO 3 February - Data from a Phase III study presented this week comparing two treatments for newly diagnosed, HIV-positive patients with cytomegalovirus (CMV) retinitis found that in each treatment group, only 7 of 73 in each group experienced progression of CMV retinitis during the four-week randomized trial. The majority of patients in both groups also cleared measurable virus from their system. The data comparing CYMEVENE-IV® (ganciclovir) and its investigational oral prodrug, valganciclovir, were presented at the 7th Conference on Retroviruses and Opportunistic Infections in San Francisco (30 Jan - 2 Feb).

In this study, 160 patients were randomized to receive either valganciclovir 900mg taken orally twice daily for three weeks followed by 900mg once daily for one week, or CYMEVENE-IV 5 mg/kg twice daily for three weeks followed by 5 mg/kg once daily for one week. The two groups were balanced with regard to CD4 counts and use of protease inhibitor therapy. During an open label extension of the trial, patients originally assigned to either group also had similar outcomes with regard to retinitis progression, side effects and survival.

"As an oral medication that provides similar blood levels to ganciclovir, valganciclovir offers significant advantages to patients in terms of convenience and it also avoids catheter-related complications." stated Daniel F. Martin, MD, associate professor, Emory School of Medicine, one of the study's principal investigators.

In the study, adverse events associated with valganciclovir and IV ganciclovir included diarrhea, fever, low blood cell counts, nausea, vomiting, and oral yeast infection. All valganciclovir adverse events have been previously observed with ganciclovir. Patients who received oral valganciclovir were able to avoid IV catheter-related adverse events.

CYMEVENE -IV was first approved in 1989 for the treatment of CMV retinitis. Adverse events associated with CYMEVENE -IV include low blood cell counts (granulocytopenia, anemia, thrombocytopenia), especially when taken with AZT. Didanosine levels can be significantly increased when didanosine is taken with valganciclovir or CYMEVENE-IV. Other side effects may include diarrhea, nausea, tingling sensation in fingers, fever and rash. In animal studies, ganciclovir was carcinogenic, teratogenic and caused aspermatogenesis. Because valganciclovir is the pro-drug of ganciclovir, it is expected to have a similar effect.

About CMV Retinitis

CMV is a member of the beta-herpes family of viruses and infects greater than 90 percent of people living with AIDS. CMV can cause a number of serious medical conditions, including CMV retinitis, a sight-threatening complication that many people with HIV/AIDS. In individuals with healthy immune systems, CMV exists in the body in a dormant state. Among individuals with compromised immune systems, however, the virus can become active and cause disease. CMV retinitis may develop with or without symptoms. Visual problems, including blind spots, distorted vision and noticeable blurring are symptoms that can signal the onset of CMV retinitis. Because these problems can happen in diseases other than CMV retinitis, a physician must make the diagnosis.