Merck & Co has asked the US Food and Drug Administration to expand the use of its cervical cancer vaccine Gardasil against tumours of the vagina and vulva, after tests showed the vaccine also offers “some protection” against forms of the human papillomavirus responsible for an added 10% of cervical tumours.

The regulatory body will decide whether to review Merck’s application in the next 60 days and, if accepted, a decision is expected within 10 months.

Gardasil is the world’s first cervical cancer vaccine, and is approved for use in girls and women aged nine to 26 against the sexually transmitted human papillomavirus (HPV). The vaccine target strains linked with 70% of cervical cancers and 90% of genital warts.

Around half of sexually active men and women are said to be infected with HPV during their lives, although the body is usually able to fight off the virus, according to the US Centers for Disease Control and Prevention.

During a decade of clinical trials for Gardasil, more than 25,000 individuals have been studied. "Gardasil has been strongly embraced by the medical community and by patients, and we are excited to submit these additional data,” said Beverly Lybrand, vice president and general manager of the Gardasil HPV Franchise of Merck Vaccines. “Merck is pleased to also file for indications to help protect against two additional gynecological cancers to further extend the value that Gardasil offers to females.”

A potential blockbuster

Gardasil has been approved in more than 60 countries, and is administered in three $120 doses. It is one of Merck's most important products and is a potential blockbuster, capable of generating as much as $2.5 billion in annual sales, according to analyst reports. Revenue from Gardasil in the fourth quarter of 2006 reached $155 million.

Gardasil has the early advantage over GlaxoSmithKline’s rival vaccine Cervarix, which was submitted for FDA approval at the beginning of April. In an interview with, GSK's chief executive JP Garnier called Cervarix "the ultimate insurance for cervical cancer” and said Cervarix could be on the market by the end of 2007, if the FDA grants the vaccine "fast track" review status and then approves it.

Gbola Amusa, analyst for Sanford C Bernstein, projects $1.5 billion in peak annual sales for Cervarix.

About 10,000 women are diagnosed with cervical cancer every year, and 4,000 die from the disease, according to the Mayo Clinic.