Efficacy of Lactococcus lactis strain Plasma on clearance of anal HPV infection in men who have sex with men: A single-center, double-blinded, randomized placebo-controlled trial (CLEAR HPV study)

Abstract

Background: Anal cancer is a human papillomavirus-related cancer; specifically, it is preceded by high-grade squamous intraepithelial lesions, which are less likely to regress spontaneously than low-grade intraepithelial lesions. Although most human papillomavirus (HPV) infections are thought to clear spontaneously, anal HPV infection persists, especially in people living with HIV. Preliminary results from a recent small randomized placebo-controlled trial of oral bacteriotherapy using a high dose of probiotics demonstrated clearance of anal high-risk HPV (hr-HPV) infection and lower onset of new high-grade squamous intraepithelial lesions among people living with HIV. Lactococcus lactis strain Plasma is a lactic acid bacterium directly activating plasmacytoid dendritic cells and inducing release of type I and III interferons via Toll-like receptor 9 stimulation. Based on these findings, oral bacteriotherapy with LC-plasma may contribute to clearing anal hr-HPV infection and reducing anal precancerous lesions by activating innate and acquired immune responses. This randomized placebo-controlled trial aims to investigate the efficacy and safety of LC-plasma therapy in clearing anal hr-HPV infection and reducing anal precancerous lesions among men who have sex with men with or without HIV infection. Methods: Participants with anal hr-HPV infection will be included and receive test capsules. A total of 150 patients will be included in the intervention group with follow-up, which will consist of HPV genotype test, cytology by anal pap smear, and biopsy with high-resolution anoscopy. The primary endpoint will be the clearance rate of the hr-HPV genotype infection at the anal site at 180 days. The secondary endpoints will be changes in anal epithelial neoplasia detected using high-resolution anoscopy at 180 days; change in abnormal cytology by anal pap smear at 180 days; change in hr-HPV genotype at the anal site at 180 days; change or percentage change in peripheral blood CD4 positive T-lymphocyte numbers in HIV-infected participants at 180 days; changes in quantitative hepatitis B surface antigen levels at 180 days in the HBV-infected participants; and adherence to the study drugs. Conclusion: This randomized controlled study will provide data on the efficacy and safety of LC-plasma as a treatment for anal HPV infection and grade 2 or 3 anal intraepithelial neoplasia.