GlaxoSmithKline said the trial results demonstrate the longest duration of protection seen in any cervical cancer vaccine trial reported to date. The data was from an extended follow-up analysis of women who participated in an initial efficacy study of GSK’s cervical cancer candidate vaccine.
The vaccine is designed to provide protection from vaccine types 16 and 18. Approximately 100 types of human papillomavirus have been identified and, of these, approximately 15 virus types are considered to cause cervical cancer. Virus types 16, 18, 45 and 31 are responsible for approximately 80% of cervical cancers globally.
The GSK cervical cancer candidate vaccine also showed 68% vaccine efficacy against precancerous lesions and 38% vaccine efficacy against abnormal pap smears, regardless of the type of cancer-causing virus detected. These results suggest evidence of protection beyond what might be expected from a vaccine that is designed to target virus types 16 and 18 alone. More specifically, the study confirmed that the candidate vaccine provides further preliminary evidence of cross-protection against incident infection with cancer-causing virus types 45 and 31 that also extended up to 5.5 years after vaccination.