New HPV Vaccine Found 90% Effective

June 28, 2007

HELSINKI -- About 90% of early signs of cervical cancer in young women can be prevented by an investigational vaccine against human papillomavirus, according to interim data.

HELSINKI, June 28 -- About 90% of early signs of cervical cancer in young women can be prevented by an investigational vaccine against human papillomavirus, according to interim data.

The interim results from PATRICIA (PApilloma TRIal against Cancer In young Adults), an international phase III investigation, are comparable to those reported in May from the FUTURE study of the quadrivalent papillomavirus vaccine known as Gardasil.

The FUTURE study found between 98% and 100% efficacy in preventing lesions caused by the oncogenic HPV 16 and 18 virus strains - the same strains targeted by the PATRICIA vaccine. (See HPV Vaccine Effective After Three Years)

The PATRICIA vaccine is being tested in an industry-sponsored randomized controlled trial whose participants are women ages 15 to 25, Jorma Paavonen, M.D., of the University of Helsinki, and colleagues, reported online in The Lancet.

The trial protocol called for an interim analysis when 23 cases of grade two or higher cervical intraepithelial neoplasia (CIN2+) were seen among the 18,644 women in the trial, Dr. Paavonen said.

The researchers found two cases of CIN2+ among women in the vaccine arm of the trial and 21 among women in the control arm, who had been given a Hepatitis A vaccine.

The difference amounted to a vaccine efficacy of 90.4% in preventing lesions, with a 97.9% confidence interval from 53.4% to 99.3%. The finding was significant at P

Among the limitations, they said in an accompanying comment, are the relatively brief follow-up -- the median was 14.8 months -- and the wide confidence intervals around the efficacy estimates.

They added that neither this vaccine nor the already-approved Gardasil vaccine do much to prevent disease in women already exposed to the targeted strains. That is why, they noted, the CDC has urged vaccination for young girls before they enter sexual maturity and thus remain unexposed to the virus.

For sexually active young women, health official making policy decisions about vaccination will have to consider other prevention strategies, such as cytological screening and HPV DNA testing, they said.