296P - Safety, efficacy, and immunogenicity of therapeutic vaccines for patients with high-grade cervical intraepithelial neoplasia (CIN 2/3) associated with human papillomavirus: A systematic review

Background

Despite the knowledge that HPV is responsible for high-grade CIN and cervical cancer, little is known about the use of therapeutic vaccines as treatment considering most studies are still in early stages. We aimed to synthesize and critically evaluate the evidence from clinical trials on the safety, efficacy, and immunogenicity of therapeutic vaccines in the treatment of patients with high-grade CIN associated with HPV.

Methods

A systematic review of clinical trials adhering to the PRISMA 2020 statement was undertaken in MEDLINE/PubMed, Embase, CENTRAL Cochrane, Web-of-Science, Scopus, and LILACS, with no data or language restriction. Primary endpoint related to the safety, efficacy, and immunogenicity of these vaccines were assessed by analyzing the adverse/toxic effects associated with the therapeutic vaccine administration; via histopathological regression of the lesion and/or regression of the lesion size and by viral clearance; and through the immunological response of individuals who received treatment compared to those who did not or before and after receiving the vaccine, respectively.

Results

A total of 1,184 studies were identified, and 16 met all criteria. Overall, the therapeutic vaccines were heterogeneous regarding their formulation, dose, intervention protocol and routes of administration making meta-analysis unfeasible. In most studies (n=15), the vaccines were safe and well tolerated, with clinical efficacy with regards to lesions and histopathological regression or viral clearance. In addition, 11 studies showed favorable immunological responses against HPV, and seven studies showed a positive correlation between immunogenicity and clinical response, indicating promising results that should be further investigated.

Conclusions

Therapeutic vaccines, although urgently needed for avoid progression of CIN 2/3 patients, still present sparse data, requiring greater investments in well-designed phase III RCT.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.