FIRST ANTI-VIRAL PROVEN TO REDUCE THE RISK OF TRANSMISSION OF A SEXUALLY TRANSMITTED DISEASE APPROVED IN CANADA -- Health Canada Approves Valtrex® Caplets for Reducing Risk of Spreading Genital Herpes to Uninfected Sexual Partners

TORONTO, Ontario (February 17, 2004) -- GlaxoSmithKline Inc. (GSK) announced today that Health Canada approved Valtrex® (valacyclovir hydrochloride) caplets to reduce the risk of transmission of genital herpes with the use of suppressive therapy. Safer sex practices should be used with suppressive therapy. A study with Valtrex, published in the January 1st edition of the New England Journal of Medicine, showed a 75 per cent reduction in the risk of transmission of symptomatic genital herpes, and a 48 per cent reduction in the risk of overall acquisition of the virus in an uninfected partner. Results from this trial have been used to support the new indication for Valtrex.

"As a physician who's been treating patients suffering with genital herpes for years, I have consistently heard from my patients that the fear of giving this disease to their partner is a major concern. The approval, of this new indication, gives patients another option, in addition to safer sex practices, to help them protect their partners," said Dr. Barbara Romanowski, Clinical Professor in the Division of Infectious Diseases, Department of Medicine, University of Alberta.

Genital herpes, most commonly caused by herpes simplex virus type 2 (HSV-2), is generally spread through skin-to-skin contact during sexual activity and often during times when there are no visible signs of a herpes outbreak. In fact, in one clinical study, up to 70 percent of people acquired 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 the Study

The study, recently published in the New England Journal of Medicine, studied 1,484 healthy, heterosexual, monogamous couples, including 118 Canadian couples in six study sites (Vancouver, Edmonton, Ottawa, Montreal, and two sites in Quebec City).

The primary endpoint of the study was to reduce the risk of transmission of symptomatic genital herpes (signs or symptoms of genital herpes confirmed with a lab test) to the uninfected partner. The study showed that the risk of transmitting symptomatic genital herpes was reduced by 75 per cent versus placebo when people used once-daily suppressive therapy with Valtrex 500 mg caplets, along with safer sex counselling. In addition, when study participants used suppressive therapy with Valtrex, the risk of overall acquisition of the virus, with or without symptoms (confirmed with a lab test), to their uninfected partner was reduced by 48 per cent vs placebo. Throughout the eight-month study, all couples were counseled on safer sex practices at all study visits and encouraged to use condoms.

"This study involved Canadian investigators and Canadian couples and the new data may have a significant impact on the way genital herpes is managed and treated in Canada," said Dr. Barbara Romanowski. "People who are sexually active and are concerned about genital herpes should talk to their health-care providers about getting tested for genital herpes. Those already diagnosed should talk to their health-care providers about ways to reduce the risk of transmission of genital herpes to their partner."

About Genital Herpes

More than 86 million people worldwide are infected with the herpes simplex virus that causes genital herpes, and eight out of 10 people may not even be aware that they are infected with the HSV-2 and may only have experienced a mild initial outbreak without recognizing recurring symptoms of the disease. In Canada, approximately 20 per cent of the population is infected with the virus. The virus never leaves the body, making it a lifelong infection that can recur at various times with or without symptoms.

Symptoms of genital herpes may include painful or itchy clusters of blisters, bumps or 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, 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. To help prevent spreading the disease to others, sexual contact should be avoided during outbreaks and latex condoms should be used at all times.

In the clinical study for the reduction of transmission of genital herpes, adverse events reported by patients included headache, nasopharyngitis (inflammation in the back of the throat) and upper respiratory tract infection. The efficacy of reducing transmission beyond eight months in couples where one partner has the HSV-2 infection and one does not has not been established. Patients should tell their doctor if they have kidney problems because their dosage of Valtrex may need to be adjusted.

About GlaxoSmithKline

GlaxoSmithKline Inc. -- one of the world's leading research-based pharmaceutical and health-care companies -- is committed to improving the quality of human life by enabling people to do more, feel better and live longer. In Canada, GlaxoSmithKline is a top 20 investor in Canadian research and development, contributing more than $100 million annually. The company is also among the top 10 corporate charitable donors and is recognized as one of the 50 best companies to work for in Canada.

For more information please contact:

Sandra Da Silva/Bev Warford

Edelman

Tel.: (416) 979-1120

GlaxoSmithKline

Alison Steeves/Catherine Jackson

Tel.: (905) 819-3363

VALTREX® is a registered trademark, used under license by GlaxoSmithKline Inc.