CERVARIX(R) Shown to Provide Longest Duration of Sustained Neutralizing Antibodies to Date

CERVARIX(R) Shown to Provide Longest Duration of Sustained Neutralizing Antibodies to Date 
Believed by experts to be important for cervical cancer prevention GRAZ, Austria, May 14

GRAZ, Austria, May 14 -- New data from an extended follow-up study show that GlaxoSmithKline (NYSE: GSK) cervical cancer candidate vaccine, CERVARIX(R) generates sustained high levels of neutralizing antibodies against the two most common cervical cancer-causing human papillomavirus types for up to 6.4 years. This is the longest duration of sustained neutralizing antibody levels observed against both virus types 16 and 18 with a cervical cancer vaccine to date.

Experts believe that neutralizing antibodies -- so-called because they have the ability to neutralize cancer-causing virus types and prevent them from infecting cells in the cervix -- are essential for cervical cancer protection. The World Health Organization has stated that neutralizing antibodies are "considered to be the major basis" of vaccine-induced protection from infection.

In addition, the study found that the level of total antibodies induced by the candidate vaccine was sustained and 11 times higher than the total antibody levels induced after natural infection for up to 6.4 years. This new data confirms previous findings from the vaccine's studies showing that, when total antibody levels are high, neutralizing antibody levels are also elevated.

"We designed our cervical cancer vaccine with our proprietary Adjuvant System, AS04, to deliver high and sustained levels of neutralizing antibodies to prevent cervical cancer over the long-term," said Philippe Monteyne, Senior Vice President, GSK Biologicals. "With nearly six and a half years of data, the vaccine has already been shown to provide the longest duration of protection of any cervical cancer vaccine to date. The high and sustained neutralizing antibody levels we observe over this same period give us confidence that the vaccine will continue to protect for even longer. This is why we are extending the study follow-up in a sub-set of women for up to 9.5 years, the longest follow-up period for any cervical cancer vaccine."

This trial included more than 700 women aged 15-25 years. During the same period that the candidate vaccine induced sustained high antibody levels for both virus types 16 and 18, the vaccine had been shown to provide 100 percent efficacy against those cancer-causing virus types.

These data were presented today at the European Society for Paediatric Infectious Diseases (ESPID) annual meeting in Graz, Austria.

Notes to the editors:
-- Safety data from 11 trials involving almost 30,000 women ages 10-72
   years who received either the candidate vaccine or a control were also
   presented at ESPID. During the course of vaccination and after the
   completion of the three-dose schedule no differences were observed
   between the candidate vaccine and control groups in serious adverse
   events, medically significant conditions and new onset of autoimmune
-- Compliance with the three-dose schedule was excellent in the 11 trials
   of the integrated safety summary.

About the study

This was an extended follow-up (EFU) analysis of women who participated in the initial efficacy study of GSK's cervical cancer candidate vaccine. The initial study was a double-blind, controlled trial of 1,113 young women between 15-25 years of age, randomized to receive three doses of the candidate vaccine, formulated with the AS04 adjuvant system, or three doses of placebo on a 0, 1 and 6 month schedule.

This extended follow-up study looked at study endpoints for 776 women from the same cohort of women for a period of up to 6.4 years post-vaccination. The trial was conducted in 28 centers in Brazil, Canada and the U.S. and evaluated the efficacy, safety and immunogenicity of GSK's candidate vaccine for the prevention of infection with cancer causing virus types 16 and/or 18, and other cancer-causing virus types, as well as prevention of associated Pap smear abnormalities and cervical precancerous lesions. In the extended follow-up study, women were evaluated for the presence of human papillomavirus DNA by PCR using cervical samples and annual cervical cytology evaluations were performed. Women were referred for colposcopy following protocol guidelines. Women were also assessed for long-term immunogenicity and safety.

About cervical cancer and its progression

Approximately 100 types of human papillomavirus have been identified to date and, of these, approximately 15 virus types are known to cause cervical cancer. Virus types 16, 18, 45 and 31 are responsible for approximately 80 percent of cervical cancers globally. Persistent infection with cancer-causing virus types can lead to the formation of abnormal cells in the cervix, which, over time, may become precancerous or cancerous. Human papillomavirus is a necessary precursor of cervical cancer. Throughout their lifetime, women may be exposed to cancer-causing virus types and are potentially at risk of developing cervical cancer.

Worldwide, more than 500,000 women will be newly diagnosed with cervical cancer and over 280,000 women will die from it each year.

About the GSK Cervical Cancer Vaccine

To date, CERVARIX(R) has been approved in more than 60 countries around the world including the 27 member countries of the European Union, Mexico, Australia, Singapore and the Philippines. Licensing applications have been submitted in more than 35 additional countries including Japan. GSK also submitted CERVARIX(R) to the World Health Organization (WHO) for prequalification in September 2007.

GSK submitted a Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) for its cervical cancer vaccine in March 2007.

About GlaxoSmithKline

GlaxoSmithKline -- one of the world's leading research-based pharmaceutical and healthcare companies -- is committed to improving the quality of human life by enabling people to do more, feel better and live longer. For company information, please visit www.gsk.com/media.

GSK Biologicals (GSK Bio), one of the world's leading vaccine manufacturers, is headquartered in Rixensart, Belgium, where the majority of GlaxoSmithKline's activities in the field of vaccine research, development and production are conducted. GSK Bio employs more than 1,500 scientists, who are devoted to discovering new vaccines and developing more cost-effective and convenient combination products to prevent infections that cause serious medical problems worldwide. In 2006, GSK Bio distributed more than 1.1 billion doses of vaccines to 169 countries in both the developed and the developing world -- an average of 3 million doses a day. Of those vaccine doses, approximately 136 million were doses of combination pediatric vaccines which protect the world's children with up to six diseases in one vaccine.