- web-based article
- Hedwig Kresse
The FDA has requested further information for GSK’s cervical cancer vaccine.
With Merck & Co’s blockbuster Gardasil currently the only approved HPV vaccine in the US, the FDA approval of Cervarix would represent a significant commercial milestone for GSK. However, the market delay now facing Cervarix is likely to restrict its impact and will enable Gardasil to retain a monopoly position in the crucial US market until the agency’s unspecified issues are resolved.
Cervical cancer, killing over 280,000 women worldwide each year, is causatively linked to the human papillomavirus (HPV), which is spread by sexual contact. Recently, both Merck and GSK have launched vaccines which could protect against infections with HPV if administered to young girls before they become sexually active. These products have a significant commercial opportunity: Datamonitor predicts annual cohort sales of $1.4 billion for the seven major markets by 2016. In addition, there is a significant catch-up opportunity in young women aged 13-26, which could be worth over $17 billion by 2016.
Comparing the two vaccines, Gardasil has numerous advantages over Cervarix: From a clinical point of view, it has a wider coverage than Cervarix, protecting against HPV subtypes 6 and 11, which cause genital warts in addition to the cervical cancer subtypes 16 and 18, which are also contained in Cervarix. Furthermore, Merck has been able to show significant cross-protection against further subtypes not included in the vaccine. In addition, data presented in November 2007 demonstrate excellent efficacy of Gardasil in women aged 24 through 45. However, unlike Gardasil, Cervarix contains a novel adjuvant, AS04, which could potentially enhance the immune response and reduce the need for booster shots.
On the commercial side, Gardasil is benefiting from its first-to-market advantage in the US market, where it was approved in June 2006 and continues to be the only available HPV vaccine until today. GSK’s vaccine, already approved in 45 countries around the world including the EU5, was filed in the US in April 2007 but has yet to receive approval.
Given the large amount of clinical data available for Cervarix, the FDA’s decision to issue a complete response letter rather than outright approval comes as a surprise. Currently, no information on the nature of the issues raised by the FDA is available. However, considering that Cervarix would be the first vaccine approved in the US containing an adjuvant other than aluminium, the questions raised could potentially be linked to AS04. Until such issues are resolved, Gardasil will retain its monopoly in the crucial US market and expand its leadership position.