The cervical cancer vaccine Gardasil, produced by Merck and Sanofi, may be more cost effective than its competitor GlaxoSmithKline’s Cervarix, according to new data published in the British Medical Journal (BMJ 2011; 343:d5775). However, the differential benefits of both remains unclear, say researchers from the Health Protection Agency.
The study has been updated from that previously used by the UK government to select which vaccine should be used in a national immunization programme for 12-13 year old school girls. Now, ahead of a decision about how this will continue, researchers have taken into account new evidence and developed various scenarios whereby the two vaccines offer different protection, cross-protection and endpoint prevention.
In the original analysis, if the bivalent vaccine, Cervarix, cost £13 to £21 less per dose than the quadrivalent vaccine, Gardasil, both vaccines would be equally cost effective. And the latest information shows that at the same price level the quadrivalent vaccine is still more cost effective and that the price differential between both vaccines is larger than their previous analysis, ie. Cervarix would need to be £19-£35 cheaper than Gardasil to be equally cost effective.
Both Cervarix and Gardasil protect against human papillomavirus 16 and 18, which have been linked to more than 70% of cervical cancer cases, but Merck’s offering also protects against anogenital warts caused by two different strains of HPV – 6 and 11. However, GSK’s Cervarix is more effective in preventing death as a result of cancer and for possibly longer than the quadrivalent vaccine.
With the decision making process ongoing, and the tender believed to expire by the end of the year there is a lot at stake for the manufacturers. One aspect the authors point to, however, is that the tender price could dramatically affect the cost effectiveness of the two products. However, as this remains confidential, they say we “will never know whether the model or the money mattered”.