Safety and Effectiveness of 3 Novel All-Oral Shortened Regimens for Rifampicin- or Multidrug-Resistant Tuberculosis in Kazakhstan.

Background: In 2019, the World Health Organization called for operational research on all-oral shortened regimens for multidrug- and rifampicin-resistant tuberculosis (MDR/RR-TB). We report safety and effectiveness of three 9-month all-oral regimens containing bedaquiline (Bdq), linezolid (Lzd), and levofloxacin (Lfx) and reinforced with cycloserine (Cs) and clofazimine (Cfz), delamanid (Dlm) and pyrazinamide (Z), or Dlm and Cfz.

Methods: We conducted a prospective cohort study of patients initiating treatment for pulmonary MDR/RR-TB under operational research conditions at public health facilities in Kazakhstan. Participants were screened monthly for adverse events. Participants with baseline resistance were excluded from the study and treated with a longer regimen. We analyzed clinically relevant adverse events of special interest in all participants and sputum culture conversion and end-of-treatment outcomes among individuals who were not excluded.

Results: Of 510 participants, 41% were women, the median age was 37 years (25th-75th percentile: 28-49), 18% had a body mass index <18.5 kg/m2, and 51% had cavitary disease. A total of 399 (78%) initiated Bdq-Lzd-Lfx-Cs-Cfz, 83 (16%) started Bdq-Lzd-Lfx-Dlm-Z, and 28 (5%) initiated Bdq-Lzd-Lfx-Dlm-Cfz. Fifty-eight individuals (11%) were excluded from the study, most commonly due to identification of baseline drug resistance (n = 52; 90%). Among the remaining 452 participants, treatment success frequencies were 92% (95% CI: 89-95%), 89% (95% CI: 80-94%), and 100% (95% CI: 86-100%) for regimens with Cs/Cfz, Dlm/Z, and Dlm/Cfz, respectively. Clinically relevant adverse events of special interest were uncommon.

Conclusions: All regimens demonstrated excellent safety and effectiveness, expanding the potential treatment options for patients, providers, and programs.