Vaccines prevent persistent infection with HPV

Vaccines produced by Merck and GSK are currently undergoing phase
III trials |
A vaccine targeting the human papillomavirus (HPV) types that are associated with 70 per cent of cervical cancers and 90 per cent of genital warts is effective in preventing persistent infection and clinical disease, according to data presented at the International Papillomavirus Conference held in Vancouver last week. Results from the study were published
online last month by Lancet
Oncology (7 April).
Luisa Villa, Ludwig Institute for Cancer Research, Brazil, and colleagues
conducted a randomised controlled trial involving 552 women aged 16 to
23 years in Brazil, Europe and the US. The women received a quadrivalent
(types 6, 11, 16, 18) HPV vaccine or placebo at day 1, month 2 and month
6. Follow up was for 36 months.
The primary endpoint was combined incidence of infection with HPV types
6, 11, 16 or 18, or cervical or external genital disease. Study results
showed that the incidence of persistent infection or associated disease
fell by 90 per cent in the vaccine group compared with the placebo group
(four events versus 36 events; P<0.0001).
The vaccine, called Gardasil and produced by Merck & Co, was generally
well tolerated and induced high titres of serum antibodies to HPV types.
Large scale studies are currently under way with over 25,000 participants
enrolled worldwide.
GlaxoSmithKline is also conducting trials on its HPV vaccine, Cervarix.
Results from a randomised controlled trial involving 1,113 women were
reported last year (Lancet 2004;364:1731) and showed that the vaccine
is 100 per cent effective against persistent HPV-16/HPV-18 infection.
At last week’s conference GSK presented further data, which provided
preliminary evidence to show that the vaccine induces cross protection
against HPV infection associated with HPV-16 and HPV-18.
Phase III trials in over 30,000 women are currently under way and GSK
expects to file for a product licence in 2006. |