Herpes Help

GlaxoSmithKline Brings to Market the First FDA-Approved Antiviral Therapy for the Suppression of Genital Herpes in HIV-Positive Individuals

by Chael Needle

Last April, the FDA granted supplemental approval to valacyclovir HCI (Valtrex), a GlaxoSmithKline product, as the first FDA-approved antiviral therapy for the suppression of recurrent genital herpes in HIV-positive individuals. Genital herpes, while not considered life-threatening, is a lifelong condition that may present challenges to those who are also living with HIV/AIDS. Fifty-eight to eighty-one percent of people living with HIV/AIDS are estimated to be co-infected with genital herpes. As co-infections go, living with genital herpes is considered much less dire than living with other viruses such as hepatitis C. Yet there is some evidence to indicate that genital herpes may be a co-factor in activating HIV, making it easier for the virus to infect cells.

Though studies of the relationships between genital herpes and HIV such as this have raised awareness about co-infection, they did not provide the impetus for the Valtrex study as much as GlaxoSmithKline’s ongoing and longstanding interest in suppressive therapies for genital herpes did. "It’s fair to say that at the time that we were putting the study together that [study] information was just becoming available," says Clarence Young, M.D., Vice President, Clinical Development and Medical Affairs, GlaxoSmithKline. "[But] I think it had been recognized even as far back as when the first case reports of severe infections in otherwise healthy men began to appear that herpes simplex recurrences were noted to be substantial illnesses in patients with HIV infection, even before we were to learn in the middle nineties of this potential relationship between herpes simplex and HIV." He continues: "Some studies have indicated that in patients you can measure an increase in HIV viral load at the time of genital herpes reactivation. There are others who have been able to culture or identify HIV RNA in genital herpes lesions, and epidemiologic studies seem to indicate a link between prior infection with herpes simplex and risk for infection with HIV."

Genital herpes typically manifests as painful or itchy cluster of blisters, bumps, and rashes in the genital area, or on the thighs and buttocks. A genital herpes outbreak can recur with or without these symptoms. Valtrex had previously been established as a safe and effective initial and recurrent treatment for the suppression of genital herpes in patients with competent immune systems. Recurrent treatment means ongoing medication; another option is episodic treatment–taking medication at the first sign of an outbreak and treating each outbreak individually. The most common side effects of Valtrex are headache, nausea, and abdominal pain. Valtrex has been shown to be effective as a suppressive agent against herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) and varicella-zoster virus. It should be noted that no antiviral has been proven to reduce the transmission of herpes.

The randomized double-blind, placebo-controlled study showed that, after six months, sixty-five percent of those patients taking Valtrex had no recurrence of genital herpes compared to twenty-six percent of those taking the placebo. The 293 HIV-positive patients studied had been on antiretroviral therapy for at least two months, had CD4 cell counts greater than 100, and had a history of recurrent genital herpes. The 194 patients receiving Valtrex took 500 mg oral doses twice daily. The most common negative side effects were headache, fatigue, and rash. The safety and efficacy of Valtrex for the episodic treatment in HIV-positive or immunocompetent individuals has not been established.

GlaxoSmithKline is currently working with the FDA on a study designed to collect more information on the suppression of genital herpes in HIV-positive individuals who have CD4 cell counts fewer than 100, but, at this time, has no plans to study any other possible linkages between genital herpes and HIV co-infection.

Chael Needle wrote about the investigational entry inhibitor, AMD-070, in the May issue.