Abstract:

Objective: To evaluate the efficacy and safety of a new treatment regimen against a standardized regimen on patients with retreated drug-susceptible pulmonary tuberculosis (PTB). Methods: This multi-centered study adopted a prospective study design, 592 patients with initially retreated PTB (including drug-susceptible, mono-drug resistance, poly-drug resistance and a few cases of smear negative retreated PTB) whom had been randomized into the new regimen arm (4H-L₂-E-Z-Lfx/4H-L₂-E; H: isoniazid, L: rifapentine, E: ethambutol, Z: pyrazinamide, Lfx: levofloxacin; body mass <50 kg, H for 0.3 g/d, E for 0.75 g/d; body mass ≥50 kg, H for 0.4-0.5 g/d, E for 0.75-1.0 g/d; regardless of body weight, L was 0.6 g, twice a week; Z: 1.5 g/d, Lfx: 0.5-0.6 g/d), and the standardized regimen arm (3H-R-E-Z/6H-R-E using conventional doses; R: rifampicin), diagnosed and hospitalized in between Jan 2019 and Dec 2021 by 24 PTB designated hospitals across 14 provinces and 3 municipalities in China were screened at baseline. According to inclusion and exclusion criteria, only those with initially retreated drug-susceptible PTB were recruited as study subjects. The rates of treatment success, treatment failure as well as incidence of adverse events were compared, safety and efficacy of the new regimen derived. Results: The final analysis included 238 cases, of which 172 cases (72.3%) were randomized into the new regimen arm, 66 cases (27.7%) into the standardized regimen arm. The success rate of the new regimen arm was higher than that of the standardized regimen arm (77.3% (133/172) vs. 62.1% (41/66); χ²=5.609, P=0.018), and the failure rate was lower than that of the standard regimen arm (4.7% (8/172) vs. 27.3% (18/66); χ²=25.083, P=0.000). There was no significant difference in the incidence of adverse reactions between the two arms (4.7% (8/172) vs. 3.0% (2/66); Fisher test, P=0.731). Conclusion: Compare to the standardized regimen, the new retreatment regimen had improved the treatment success rate and lowered the rate of treatment failure among patients with retreated drug-sensitive PTB, demonstrated good overall safety and efficacy profile.

Key words: Tuberculosis, pulmonary, Retreatment, Clinical protocols, Program evaluation, Treatment outcome