News Release

Stronger form of ganciclovir offers simpler treatment for CMV retinitis in immune-compromised patients

Peer-Reviewed Publication

Emory University Health Sciences Center

Researchers have successfully demonstrated the effectiveness of a new experimental oral form of the drug ganciclovir to treat cytomegalovirus (CMV) retinitis, a blinding disorder that is the most common ocular manifestation of AIDS. Daniel F. Martin, M.D., who is an associate professor at the Emory Eye Center and lead investigator for the multicenter valganciclovir trial, presented the findings at the 7th Conference on Retroviruses and Opportunistic Infections in San Francisco on Jan. 31.

CMV, a common member of the herpes family of viruses, is present in nearly all human bodily fluids and causes few symptoms in healthy people. The National Institutes of Health estimate that up to 85% of the U.S. population may be infected with the virus by the time they reach adulthood. It causes illness only in immune-compromised people, such as those with AIDS or transplant recipients, and in babies whose mothers are infected early in their pregnancy. In AIDS patients, it often takes the form of CMV retinitis, an infection of the light-sensing tissue in the back of the eye that can lead to blindness. Ganciclovir is the most common drug to treat CMV retinitis. It can be administered in one of three forms: intravenous infusion, eye implant or oral medication. "Ganciclovir is commonly administered by intravenous infusion through a central in-dwelling catheter once or twice a day," says Dr. Martin. "Unfortunately, these infusions can cost up to $50,000 a year, place the patient at risk for sepsis, and can significantly impact his or her quality of life."

Research has shown that the ganciclovir implant, a small, pea-sized pellet inserted into the eye, is the most effective form of treatment for CMV retinitis. Because the implant treats only intraocular disease, the patient must receive ganciclovir to reduce the risk of CMV disease elsewhere. It is most effective when used in conjunction with an oral form of ganciclovir. But, the body does not absorb the oral form through the bloodstream as efficiently as the intravenous form.

"Until now, oral ganciclovir required up to 18 pills a day to provide the required amount of medication in the system to effectively treat CMV retinitis," says Dr. Martin. "Results of our multicenter study demonstrate that valganciclovir, an oral pre-drug that rapidly converts to ganciclovir, is very similar to intravenous ganciclovir in every parameter we evaluated, including amount of drug in the bloodstream needed for the resolution of the CMV. Being able to achieve inactive CMV retinitis with two pills twice a day will be a tremendous advantage for patients," he continued.

If the drug is granted FDA approval, valganciclovir¹s clinical use could be widespread. It can be used in conjunction with the eye implant as adjuvant therapy or alone, depending on the patient¹s condition.

"Valganciclovir also has the potential to become an important drug for preventing new CMV disease," Dr. Martin says. "A multicenter study is currently underway to evaluate valganciclovir in patients who have documented evidence of CMV in their bloodstreams, but no clinical symptoms." It potentially can help prevent or treat CMV disease in solid organ and bone marrow transplant recipients, whose immune systems are pharmaceutically suppressed to prevent donor organ rejection. Valganciclovir is made by the pharmaceutical company, Roche. Dr. Martin is the principal investigator for the Roche Valganciclovir Study Group, which conducted an international 50-center study comparing the use of valganciclovir with the intravenous infusion form of ganciclovir. At the January 31 conference, he will report findings from the group¹s study, which enrolled 160 patients with newly diagnosed CMV retinitis.

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