GlaxoSmithKline has filed its cervical cancer vaccine Cervarix for approval in Europe, putting it in a race with a rival product, Gardasil, developed by Merck & Co and partner Sanofi-Aventis.

Both Cervarix and Gardasil trigger antibodies against human papillomavirus (HPV), a sexually transmitted infection that causes cervical cancer, the second-most common malignancy in women worldwide. But Gardasil looks almost certain to claim first-to-market advantage in both European and the USA, where it has already been submitted for approval.

GSK said last month plans to submit Cervarix for approval by the end of the year in the USA. Gardasil was recently granted a priority review by the US Food and Drug Administration (FDA), and could be on the market there as early as June.

But analysts believe there is room for both products to make strong sales, as demand for HPV vaccination is expected to be huge. If treated early, five-year survival rates for cervical cancer can be as high as 80%-90%, but they plummet to 14% if the cancer remains untreated and spreads.

Gardasil could quickly achieve sales of $500 million, rising to $3 billion at peak, according to analysts, while Cervarix has also been tipped as a $2 billion-plus product.