Cervarix protects against HPV for over 5 years

UK-based drug major GlaxoSmithKline says that its cervical cancer vaccine candidate Cervarix has demonstrated 100% efficacy in preventing precancerous lesions caused by human papillomavirus types 16 and 18 for up to 5.5 years after vaccination. The findings are based on data from a long-term follow up study and were presented at the annual meeting of the American Association of Cancer Research, held in Los Angeles, USA.

The original study enrolled 1,113 women between the ages of 15 and 25 who were randomized to receive three doses of Cervarix, formulated to include the firm's AS04 adjuvant system, or placebo. The follow-up assessment, which ran for 67 months, examined data from 776 women from the treatment group, specifically, measuring HPV DNA from cervical samples.

GSK said that the vaccine also showed 68% efficacy against precancerous lesions of type CIN2+, regardless of the type of virus responsible for the infection. The firm added that the agent provided cross-protective immunity against infections caused by HPV subtypes 45 and 31, which are also linked to the development of cervical cancer. Further analysis revealed that, after five years, the average level of antibodies to virus types 16 and 18 was 11 times greater than those observed following untreated viral infection.