Vaccines aimed to block cancer

The race is on to produce "the biggest vaccine ever": a jab that will protect women from the virus behind two-thirds of all cervical cancer.

It could save the lives of about 70 New Zealand women a year and as many as 1000 in the UK alone. The vaccine also might eventually bring an end to the era of the routine smear test.

The market for such a revolutionary product could be worth $100 billion over the lifetime of a mass vaccination programme and could transform the financial fortunes of the companies that are developing it.

Which is why Merck, the embattled US pharmaceutical giant, promised this week to accelerate the large-scale human trials that will prove whether its vaccine - called Gardasil - can be approved for launch.

Raymond Gilmartin, Merck's president, said it was now aiming to file for approval in the spring of next year, with a launch about a year after that.

Merck has been stung by the claim of GlaxoSmithKline, the UK's biggest drug maker, to now be just "months rather than years" behind.

GSK has dramatically accelerated its work and last month brought forward the date when it plans to file for its first regulatory approval, previously 2008, to 2006, saying it recruited volunteers to its trials much faster than expected.

It is Jean-Pierre Garnier, the chief executive of GSK, who has described a cervical cancer vaccine as potentially the biggest ever. Indeed, he thinks it might become one of the biggest selling pharmaceutical products of all time.

Both companies' vaccines work in the same way. They mimic strains of the sexually transmitted human papillomavirus (HPV), which causes 70 per cent of cervical cancers. Because they stimulate a response by the immune system, it can then fight off the virus. At least 50 per cent of women in the West are believed to have been exposed to HPV, which sometimes causes genital warts, but most are unaware of it as they do not show any symptoms.

In 1 or 2 per cent of cases it goes on to cause abnormalities in the cervical cells, which may develop into cancer.

Both Merck and GSK, for different reasons, need their vaccine to be a hit. Mr Gilmartin is looking to save the company from oblivion after Vioxx, its arthritis painkiller, had to be withdrawn from the market on safety fears, opening the door to vast but as yet unquantifiable compensation claims.

Both companies have published impressive data on the effectiveness of their vaccines in trials involving thousands of women, and now much larger studies are under way. There is also work being done inside both companies on adding additional strains of HPV to the vaccine, so that it might prevent more than 70 per cent of cancers.

Many of the highest scientific hurdles have been jumped by GSK and Merck now, but there are political ones that remain.

Dr Garnier is undaunted, saying: "This is going to be a mandatory vaccine."

CANCER VACCINE

* Two giant drug firms are in a race to create a vaccine to protect women against cervical cancer, which kills 288,000 women a year.

* The success of the work could deliver the winner billions of dollars.

* The vaccines work by mimicking strains of a sexually transmitted virus and stimulating a response by the immune system.

- INDEPENDENT