Uro-vaxom (OM-89) for chronic UTI prevention: an updated meta-analysis, meta-regression and trial sequential analysis of recent clinical evidence.

Abstract

Introduction: Recurrent urinary tract infections (UTIs) are a common health issue that affects patients' quality of life and healthcare systems. To reduce antibiotic use, non-antimicrobial treatments, such as Uro-Vaxom (OM-89), have been proposed to prevent UTI recurrence by enhancing immune response. Still, despite being available for many years, the evidence for its effectiveness remains unclear. This updated systematic review and meta-analysis aims to evaluate the efficacy of OM-89 in reducing UTI recurrence, increasing sample size compared to previous reviews.

Evidence acquisition: A systematic review was conducted using MEDLINE, Embase, Scopus, Cochrane, Web of Science, and Google Scholar, following the PRISMA guidelines. We included randomized controlled trials (RCTs) comparing OM-89 with placebo in adult patients with a history of recurrent UTIs. Study selection and data extraction were performed by multiple reviewers, and a random-effects model was used for data pooling. Our primary outcome was the recurrence rate of symptomatic UTIs, while secondary endpoints included the rate of positive urine cultures at 3 and 6 months post-intervention. Risk of bias was assessed using the Cochrane Risk of Bias 2 tool, and statistical analysis was conducted using RStudio software. Additionally, we performed a meta-regression incorporating all included studies for primary endpoint.

Evidence synthesis: We retrieved eight RCTs, comprising 674 patients in the OM-89 group and 677 patients in the placebo group. Our analysis showed a lower rate of symptomatic UTIs in the intervention group (OR 0.48; 95% CI 0.23-0.97; P<0.01; I²=81%). Similarly, bacteriuria at both 3 and 6 months after treatment was less frequent in patients treated with OM-89 compared to placebo (OR 0.23; 95% CI 0.10-0.53; P=0.03) and (OR 0.45; 95% CI 0.23-0.89; P=0.02), respectively. Meta-regression revealed a trend suggesting that the effectiveness gap between OM-89 and placebo has decreased in more recent research.

Conclusions: Although initial meta-analysis results indicated that OM-89 was effective in reducing UTI recurrence, meta-regression reveals a decline in its efficacy in more recent studies. This decreasing effectiveness over time suggests that OM-89 may no longer be a reliable option for preventing recurrent UTIs.