Clinical and Microbiological Efficacy of the Antibacterial Drug Fluorothiazinone in the Treatment of Recurrent Cystitis in a Randomized Clinical Trial

Background/Objectives: New data on the pathogenesis of recurrent urinary tract infections (rUTIs) and the growing level of bacterial resistance to antibiotics require a revision of patient treatment strategies and a search for non-antibiotic approaches to the treatment and prevention of UTIs. The aim of this study was to investigate the clinical and microbiological efficacy of a new, non-traditional antibacterial drug, Fluorothiazinone (FT). Methods: We conducted an open-label, randomized, multicenter cohort clinical trial, phase III, at 12 hospitals in Moscow and St. Petersburg. A total of 280 patients were randomized into two groups in a 1:1 ratio to receive FT at a dose of 1200 mg/day for 14 days or furadonin at a dose of 400 mg/day for 7 days. Clinical and microbiological cures were assessed 7, 14, and 28 days after the start of therapy. Results: For the primary efficacy endpoint, clinical cure at day 28, the recovery rate was 91.7% in patients receiving FT and 92.8% in patients receiving furadonin, the hypothesis of non-inferiority of FT compared to the standard furadonin regimen was confirmed by two-sided 95% confidence intervals. The proportion of patients with clinical cure on days 7 and 14 also did not differ in the two groups. An assessment of microbiological eradication at all observation times in our study demonstrated that FT, whose mechanism of action is associated with the suppression of pathogen virulence, possesses antibacterial activity comparable to that of the antibiotic furadonin, leading to the eradication of pathogens causing rUTIs. The frequency of microbiological relapses after 28 days of treatment was 19.6% in the group receiving FT and 22.2% in the group receiving furadonin. Both study groups were comparable in the severity of adverse events (AEs). A definite relationship with the study drugs was identified for 1 (11.1%) AE after taking FT and 8 (88.9%) AEs after taking furadonin. Conclusions: Clinical trials in patients with recurrent cystitis have demonstrated the intrinsic antibacterial activity of FT, equal clinical and microbiological efficacy compared to first-line drugs for the treatment of recurrent cystitis, as well as a high level of safety, indicating the potential for the use of drugs with a new mechanism of action in the context of growing antibiotic resistance.