Sanofi Pasteur MSD’s top-selling Gardasil has been thrust into the spotlight again after the European Medicines Agency said there have been two sudden and unexpected deaths in young women who had received the vaccine as a prevention against developing cervical cancer.

However, within the context of the 1.5 million women who have already been vaccinated on the continent, and because no causal relationship between the vaccine and the two fatalities has been established, the EMEA has decided that the benefits of Gardasil outweigh its risks. There will be no changes to the product information.

One of the deaths occurred in Austria and the other in Germany. In both cases, the cause of death could not be identified, says the agency. However, Gardasil’s safety will continue to be monitored.

Two cervical cancer vaccines are currently approved in Europe – Sanofi Pasteur MSD’s Gardasil and GlaxoSmithKline’s Cervarix – and both offer protection against HPV types 16 and 18, which collectively account for around 73% of cases on the continent. However, in the USA, Cervarix has come up against a stumbling block in the shape of the country’s drug regulator, which in December requested additional information prior to approval, putting it even further behind its rival.

Indeed Merck’s vaccines unit looks set to put in a star turn in 2008, with unit expected to reel in $4.8-$5.2 billion, boosted by Gardasil. The introduction onto the market of innovative, high price vaccines is expected to quadruple the sector to $16 billion by 2016, according to a recent report by market analyst Datamonitor.

Whether the emergence of more unexplained deaths will limit Gardasil’s huge potential remains to be seen. It had previously been spotlighted by US pressure group Judicial Watch, which in October reported 11 fatalities amongst young women who had received the vaccine plus more than 1800 adverse events.

A spokesperson from Sanofi Pasteur MSD has previously told PharmaTimes World News that such spontaneous adverse event reports show a temporal rather than causal relationship and that the data need to be systematically evaluated before the company and the regulators can make an accurate judgement. He also noted that the dataset filed with regulators contained data on 25,000 women, therefore its safety profile has been well documented, with heart problems and/or blood clotting not listed as potential side effects.

Cervical cancer is the second most common form of the disease after breast cancer in women aged 15-44 years, with 33,000 cases and 15,000 deaths in the EU each year.