Public Release: 

Results of pivotal study for GlaxoSmithKline's Valtrex published in New England Journal of Medicine

First and only anti-viral proven to reduce sexual transmission of an STD

Hill and Knowlton

Research Triangle Park, N.C., January 1, 2004 - GlaxoSmithKline today announced the publication of results from a clinical trial evaluating VALTREX® (valacyclovir HCl), an oral antiviral, in the reduction of transmission of genital herpes, in the Jan. 1 edition of the New England Journal of Medicine1. VALTREX significantly reduced the risk of transmitting herpes infection to a heterosexual partner as compared to placebo. Results from this trial have been used to support a new label indication for VALTREX in the reduction in risk of transmission of genital herpes when used in combination with safer sex practices. This new indication has been approved in the USA, Australia and Finland.

The transmission study with VALTREX published in the latest edition of NEJM was a randomized, double-blind, placebo-controlled trial involving 1,484 healthy, heterosexual, monogamous couples in 21 countries. The primary endpoint of the study was to evaluate the reduction in risk of transmission of symptomatic genital herpes (signs or symptoms of GH confirmed with a lab test) to an uninfected partner with use of suppressive therapy with VALTREX. The study showed that once-daily suppressive therapy with VALTREX 500 mg caplets reduced the risk of transmission of symptomatic genital herpes by 75 percent versus placebo (0.5 percent vs 2.2 percent). In addition, suppressive therapy with VALTREX reduced the risk of overall acquisition of the virus (with or without symptoms confirmed by a lab test) by 48 percent versus placebo (1.9 percent vs. 3.6 percent). In addition, VALTREX significantly reduced the number of recurrences in the infected partner versus placebo, consistent with previous studies.

Throughout the eight-month study, all couples were counselled on safer sex practices at all study visits. The principles of safer sex practices were (1) to avoid sexual contact when the infected partner had any symptoms of genital herpes and (2) consistent and correct use of condoms during all sexual contacts.

The most commonly reported side effects in the study were headache (VALTREX 29%, placebo 26%), nasopharyngitis (VALTREX 16%, placebo 15%), and upper respiratory infection (VALTREX 9%, placebo 10%). The effect of VALTREX on transmission of genital herpes has not been established in immunocompromised individuals or same-sex couples.

In August 2003, the U.S. Food and Drug Administration (FDA) approved a supplemental new drug application (sNDA) for VALTREX tablets for suppressive therapy in otherwise healthy adults with genital herpes in order to reduce the risk of heterosexual transmission of genital herpes. Approvals for the reduction of transmission of GH were also obtained in Australia and Finland during 2003.

Larry Corey, M.D., lead study investigator and professor, Laboratory Medicine and Medicine, University of Washington and head of the Program in Infectious Diseases, Fred Hutchinson Cancer Research Center, commented: "This is the first demonstration that an antiviral medication can reduce the transmission of a sexually transmitted chronic viral infection. As genital herpes is widespread in nearly all parts of the world, these results offer an additional approach for both patients and healthcare providers for what is the major concern of most persons with genital herpes; reducing the risk of transmitting their infection to their sexual partner."

About Genital Herpes
In 1991, an estimated 1 in 5, or 45 million, Americans were infected with the virus that causes genital herpes. Experts estimate that up to 60 million Americans have the virus that causes genital herpes and the CDC estimates that approximately 1 million people are infected each year. However, as many as nine out of ten of those infected are unaware they have genital herpes and may only have experienced a mild initial outbreak without recognizing recurring symptoms of the disease. Symptoms of genital herpes may include painful or itchy clusters of blisters, bumps and rashes in the genital area, or on the thighs or buttocks. Many people confuse genital herpes symptoms with other conditions such as urinary tract infections (UTIs), ingrown hair, jock itch, zipper burn, allergic reactions, vaginal infections, a cut or a scratch, or irritation from sexual intercourse or tight jeans.

Though the disease is most contagious during an outbreak, it can also be contagious between outbreaks when no signs and symptoms are present. In fact, in clinical studies, the majority of people got genital herpes from a partner who knew they had genital herpes but reported no signs or symptoms at the time of recent sexual activity.

About Valtrex
VALTREX is also indicated for the treatment or suppression of genital herpes in otherwise healthy individuals and for the suppression of recurrent genital herpes in HIV-infected adults with CD4+ counts >100cells/ìL. Adverse events reported with VALTREX include headache, nausea, abdominal pain, fatigue and rash. No data are available on the efficacy of suppressive therapy with VALTREX of more than one year's duration in healthy patients (six months in HIV-infected patients), or when started more than 24 hours after the onset of signs and symptoms for episodic therapy. Patients should tell their doctor if they have kidney problems because their dosage of VALTREX may need to be adjusted. To avoid a potentially serious complication, patients should tell their doctor if their immune system is not normal because of advanced HIV disease, bone marrow or kidney transplant. There is no cure for herpes and even with treatment it may be possible to spread herpes. For more information on VALTREX, visit


About GlaxoSmithKline
GlaxoSmithKline is one of the world's leading research-based pharmaceutical and health care companies. GlaxoSmithKline is committed to improving the quality of human life by enabling people to do more, feel better and live longer. For more information on GlaxoSmithKline, visit

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