GlaxoSmithKline (GSK) announced the positive opinion yesterday, with the candidate vaccine now going before the European Commission for final approval and marketing authorisation anticipated in the coming months.
The CHMP granted a positive opinion for the vaccine for the prevention of precancerous lesions and cervical cancer causally related to human papillomavirus (HPV) types 16 and 18. The opinion was given following evaluation of data from the largest Phase III cervical cancer vaccine efficacy trial to date, GSK said.
GSK's vaccine has been formulated using the company's novel adjuvant, which has been shown to offer significant benefits over traditional aluminium salt-based adjuvants (such as the one used in Merck's Gardasil).
The AS04 adjuvant is designed to boost the immune response and increase the duration of protection against cancer-causing virus types. This is particularly important as women may acquire infections caused by HPV throughout their lifetimes, and as such need reliable, long-term protection. The immune response generated through use of AS04 has been shown to last up to 5.5 years.
AS04 is formulated with aluminium hydroxide combined with a novel substance known as monophosphoryl lipid A (MPL). MPL directly activates key immune mechanisms, enhancing the initiation of the immune response by activating innate immunity leading to an improved cellular and humoral adaptive immune response, according to GSK.
In clinical trials, Cervarix adjuvanted with AS04 compared to the same antigens adjuvanted with aluminium hydroxide alone showed antibody titres at least two fold higher (analysed up to four years after first dose), 'significantly higher' antibody titres (analysed up to four years after first dose), and B cell memory frequency approximately two fold higher (analysed up to two years after first dose).
Earlier this year GSK announced interim results from the Phase III study which revealed that Cervarix provides up to 100 per cent protection against advanced precancerous lesions caused by HPV types 16 and 18, which are responsible for 70 per cent of all cervical cancers. The study also strengthened preliminary evidence suggesting that the vaccine provides protection against infection from additional cancer-causing virus types.
GSK is so confident in its cervical cancer vaccine candidate that in January it announced plans to initiate a direct head-to-head trial between Cervarix and Merck's high-profile vaccine Gardasil, the world's first cervical cancer vaccine.
The objectives of the trial will be to compare the immune responses to cancer-causing virus types 16 and 18 in various age groups, as well as immune responses to other cancer-causing virus types.
Patient enrolment is underway, with over 1,000 women expected to be involved in the trial. Results are expected 12 months after enrolment is complete, with extended follow-up continuing for 17 months after the last study visit.
Cervarix is currently only approved in Australia, where in May it was granted approval for use in females aged 10 to 45 - the first time a cervical cancer vaccine has been explicitly indicated for women over 26 anywhere in the world.
GSK submitted at Biologics License Application (BLA) for the vaccine in the US in March this year, but doesn't expect a decision until the end of the year having not been given a priority review for the prophylactic vaccine.
Gardasil generated $235m (€170m) in sales for Merck & Co. in 2006, after gaining approval a little over a year ago.
