Real-world treatment outcomes of a 6-month fluoroquinolone-containing regimen for isoniazid mono-resistant pulmonary tuberculosis in Korea.

PURPOSE: Prospective real-world evidence on the effectiveness and safety of the World Health Organization-recommended 6-month fluoroquinolone-containing regimen (FqREZ) for isoniazid mono-resistant tuberculosis (Hr-TB) remain limited. METHODS: We conducted a multicenter prospective observational cohort study within the Korean national TB program between 2016 and 2024. Adults with pulmonary Hr-TB received either a 6-month FqREZ or alternative non-FqREZ. The primary outcome was a favorable outcome, defined as treatment success without recurrence within 12 months after treatment completion. The secondary outcome was the occurrence of serious adverse events during treatment. Multivariable logistic regression was performed to assess factors associated with study outcomes. RESULTS: Among 99 participants with pulmonary Hr-TB, 55 (55.6%) received FqREZ. Favorable outcomes occurred in 71% with FqREZ and 73% with non-FqREZ (p > 0.99). After adjustment, FqREZ was not associated with a higher likelihood of favorable outcome (adjusted odds ratio, 0.51; 95% confidence interval, 0.17-1.45). No recurrence was identified within 12 months after treatment completion in both treatment groups. Serious adverse events occurred in 29.1% of FqREZ and 20.5% of non-FqREZ recipients (p = 0.361) with hepatobiliary events being most common. CONCLUSIONS: In this prospective real-world cohort, the 6-month FqREZ regimen achieved treatment outcomes comparable to those of non-fluoroquinolone regimens, with a similar safety profile, in pulmonary Hr-TB.