Is another indication for GlaxoSmithKline's ($GSK) HPV shot in the cards? A new study, published in Lancet Oncology, found Cervarix protected women from anal cancer, which can be caused by the two strains of human papillomavirus targeted by the vaccine, HPV 16 and 18.
"There was strong protection with the vaccine against anal infection," lead author Aimee Kreimer of the National Cancer Institute told Reuters, adding, "We know anal HPV 16, but also 18, cause the bulk of anal cancers. We know if we remove the infection, it will greatly reduce the likelihood for the cancer."
The researchers analyzed tissue specimens in 4,210 healthy women, half of whom then received the vaccine. The other half got a placebo injection. Four years later, the women were tested for HPV 16 and 18 infections in the anus and cervix. The vaccine prevented 62% of anal cancers and 77% of cervical cancers caused by HPV infection, compared with cancer rates in the general population, Reuters reports. The shot prevented 84% of anal infections with HPV and 89% of cervical HPV infections.
The researchers also found cross-protection from the vaccine against three other cancer-causing HPV strains. "We're getting more bang for our buck than we realized with this vaccine," Kreimer said.
Merck's ($MRK) Gardasil, Cervarix's competitor, has already won FDA approval to prevent anal cancers in men and women. But that approval came on the basis of a study in men. Kreimer told Reuters she isn't sure her data would be enough to justify broader use of Cervarix, but that the study does add to evidence that HPV vaccination protects women from anal cancer. "I do think it is getting close to a tipping point," she said, "but I don't know if we're there yet."
- read the Reuters news