GlaxoSmithKline has entered into the battle for the potentially lucrative cervical cancer vaccine market by seeking approval in the USA for Cervarix, which it hopes will compete for the top spot with Merck & Co’s Gardasil.

GSK has submitted a Biologics License Application for Cervarix to the US Food and Drug Administration and if approved, the vaccine will be indicated for the prevention of cervical cancer and precancerous lesions associated with human papillomavirus. The filing includes data from clinical trials in almost 30,000 females aged 10 to 55 “and reflects an ethnically diverse population,” the company noted, adding that the submission also contains positive results from the largest Phase III cervical cancer vaccine efficacy trial to date, which was conducted in more than 18,000 women aged 15 to 25. GSK has also filed for approval of Cervarix in Europe, Australia, Canada, and “major countries” in Asia and Latin America.

The UK drugs giant is confident that Cervarix is going to make a big impression on the market, despite Merck’s headstart with Gardasil, thanks to the fact that it employs an adjuvant system called AS04, “intended to enhance immune response and increase duration of protection.” GSK recently started a study to compare the immunogenicity of Cervarix against Gardasil, which has been available in the USA since last June.

GSK’s chief executive Jean-Pierre Garnier said that the filing is an important milestone for the firm, adding that “we believe that the best possible protection against cervical cancer will include routine screening together with a vaccine designed to provide targeted, durable protection against the most common cancer-causing virus types.” The filing includes a considerable amount of data for virus types 16 and 18 that cause 70% of cervical cancer cases worldwide, as well as data for other virus types that can lead to cervical cancer.

It is the durable protection claim that makes GSK feel that it can make up for time lost to Gardasil and some analysts feel that being second to market will not prevent Cervarix from generating sales of $2.5 billion by 2011 and getting a 35% market share in the USA, and 50% abroad. The FDA is scheduled to decide in a month on whether it will give GSK’s Cervarix application a priority review.

The cervical cancer vaccine issue is a hot one at the moment and although Gardasil sales are growing strongly, much controversy surrounds the efforts in some US states to mandate the vaccine for schoolgirls, and Merck recently suspended its lobbying campaign for laws requiring use of its treatment. However countries in Europe seem less concerned about the ethics of such a move and France's High Counsel of Public Health has just recommended vaccination for girls aged 14. Germany’s Standing Vaccination Committee has also recommended that all girls between 12 and 17 years of age receive the vaccine, while Italy has stated that it will vaccinate 12-year-old girls once the vaccination centres are set up.