Daniel Martin, an ophthalmologist at the Emory Eye Center and associate professor with the Emory School of Medicine, was the lead investigator in a clinical trial that has shown a new oral drug, Valcyte (valganciclovir), is as effective as the previous intravenous treatment for the treatment of cytomegalovirus (CMV) retinitis. The new finding was reported in the April 11 New England Journal of Medicine.

CMV retinitis is a potentially devastating viral disease which damages eyesight and can lead to blindness in patients with AIDS. Once the condition is diagnosed, treatment can be lifelong, often requiring long-term use of an indwelling catheter. As the first potent oral treatment, Valcyte is more convenient for patients and does not cause the problems that are associated with the use of a chronic indwelling catheter.

“This study demonstrates that Valcyte offers efficacy comparable to that of Cytovene, the most widely used agent in induction therapy for CMV retinitis, and does not require the use of a chronic indwelling catheter which can be problematic for some patients,” Martin said. “I expect that Valcyte will become a mainstay in the treatment of AIDS patients with CMV retinitis.”

Approved by the U.S. Food and Drug Administration in March 2001 for the induction and maintenance treatment of CMV retinitis in patients with AIDS, Valcyte works by enhancing the absorption of ganciclovir through the gastrointestinal tract. Once in the bloodstream, ganciclovir enters cells infected with CMV and inhibits replication of the virus. In patients who have CMV retinitis, Valcyte stops viral replication, thus inhibiting further retinal damage, and preserving vision.

In the study, 160 patients with AIDS and newly diagnosed with CMV retinitis were randomly assigned to receive either Valcyte tablets (900 mg taken orally twice daily for three weeks, followed by 900 mg once daily for one week maintenance therapy) or intravenous Cytovene solution (5 mg/kg twice daily for three weeks followed by 5 mg/kg once daily for one-week maintenance therapy).

After four weeks of treatment, results of both groups were evaluated by masked review of retinal photographs. Results showed that after four weeks of treatment with Valcyte, the number of patients whose disease had progressed and the number of patients who had negative CMV cultures and PCR were virtually identical to those treated with Cytovene. In addition, the pharmacokinetic profiles for each treatment were remarkably similar.

The most common adverse effect was diarrhea, which occurred more often in the valganciclovir group (19 percent versus 10 percent in the ganciclovir group). Intravenous catheter-related events occurred in 9 percent of the IV ganciclovir patients and four percent of valganciclovir patients (catheter present for other reasons).

CMV a member of the herpes family of viruses, infects approximately 50 to 75 percent of the U.S. adult population and 90 percent of people with HIV. In individuals with healthy immune systems, CMV exists in the body in a dormant state. However, among individuals with compromised immune systems, the virus can become active and cause disease. CMV retinitis, which damages eyesight and can cause blindness, is the most common CMV-related condition in people living with AIDS, affecting between 10 and 25 percent of persons with late-stage AIDS.