A report from an international working group of researchers suggests that the process of evaluating human papillomavirus vaccines can be significantly shortened.
The group, convened by NCI and the International Agency for Research on Cancer, examined evidence to determine whether vaccine efficacy can be established at an earlier stage of virological infection, rather than clinical onset of disease in the cervix. They also looked at whether immunobridging trials could be sufficient for licensure under specific circumstances.
The group concluded that for most situations, such as infection of the cervix or anus of young adults (e.g. individuals aged 16–26 years), “persistent HPV infection of 6 months or longer be used as an appropriate end-point when protection is being evaluated, with reduction in disease being verified by post-licensure monitoring.”
“If vulvar/vaginal protection is to be evaluated in a trial, it is recommended to use HPV 16/18-positive high-grade vulvar intraepithelial neoplasia/vaginal intraepithelial neoplasia (VIN/VAIN) as a disease end-point, as there is relatively little experience in using persistent HPV infection as a surrogate end-point for vulvar and vaginal disease,” the report continued. “A persistent infection end-point could be considered at these two sites if subsequent studies validated the ability to detect persistent infection at these sites.”
The report, titled Primary End-points for Prophylactic HPV Vaccine Trials, provides a series of technical recommendations for clinical efficacy trials.
“These recommendations could help reduce the cost and duration of clinical studies and facilitate research in important areas, such as reducing the number of doses of the current vaccine, or evaluating new vaccines similar to those already licensed,” said Rolando Herrero, head of the Prevention and Implementation Group at IARC and organizer of the working group.
