Efficacy and safety of therapeutic HPV vaccines to treat CIN 2/CIN 3 lesions: a systematic review and meta-analysis of phase II/III clinical trials

Scientists at the International Agency for Research on Cancer (IARC) have completed a study to assess the efficacy and safety of the use of therapeutic human papillomavirus (HPV) vaccines in phase II/III trials to treat women with moderate to advanced cervical lesions, and to achieve clearance of high-risk HPV from the cervix. The study was published in the journal BMJ Open.

Through a systematic review and meta-analysis, researchers in the Early Detection, Prevention, and Infections Branch at IARC determined that of 734 women with moderate to advanced cervical intraepithelial neoplasia (CIN) who received therapeutic HPV vaccines, 54% showed regression of their lesions. The proportion of HPV clearance in vaccinated women was 42%, which was more than double the clearance observed in unvaccinated women.

The study concluded that the vaccines had a modest efficacy in treating grade 2 or 3 lesions (CIN 2/3), and that the observed high HPV clearance rates should be studied further to determine whether therapeutic HPV vaccination may lead to a more rapid and durable elimination of the virus in HPV-positive women with no precancerous or cancerous lesions.

The World Health Organization (WHO) is currently developing product performance characteristics (PPCs) for therapeutic HPV vaccines, through a consultative and iterative process with global partners including the Bill & Melinda Gates Foundation. This systematic review will provide valuable evidence to this WHO initiative, which aims to add a novel strategy for cervical cancer elimination to the existing ones.

Ibrahim Khalil A, Zhang L, Muwonge R, Sauvaget C, Basu P.
Efficacy and safety of therapeutic HPV vaccines to treat CIN 2/CIN 3 lesions: a systematic review and meta-analysis of phase II/III clinical trials
BMJ Open, Published online 24 October 2023;
https://doi.org/10.1136/bmjopen-2022-069616
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