Treatment outcomes of multidrug-resistant TB with selective use of new drugs.

SETTING: This was a nationwide cohort study.OBJECTIVE: To assess the treatment outcomes in patients with multidrug-resistant TB (MDR-TB) who underwent treatment guided by a national TB expert review committee in South Korea.DESIGN: We enrolled all patients with MDR-TB submitted for approval for the use of new TB drugs, including bedaquiline and delamanid, from 2016 to 2019. Patients were classified into two groups: those on new TB drugs and those not on new TB drugs. We compared the final treatment outcomes between the groups and analysed the prognostic factors.RESULTS: Of a total of 785 patients, respectively 754 (96.1%) and 31 (3.9%) were classified into the "new TB drugs" group and "no new TB drugs" group. The new TB drugs group had a higher acid-fast bacilli smear positivity rate and higher resistance rate to second-line injectable drugs or fluoroquinolones. Of all the patients, 97.8% achieved culture conversion (97.7% vs. 100%), and 80.4% achieved treatment success (80.2% vs. 86.7%); there was no difference between the two groups.CONCLUSIONS: New drugs are currently recommended for use in all MDR-TB treatment regimens, and the use of new drugs, as determined by an expert committee, in mainly quinolone-susceptible MDR-TB, did not compromise the treatment success rate.