Impact of Prior Tuberculosis Treatment With New/Companion Drugs on Clinical Outcomes in Patients Receiving Concomitant Bedaquiline and Delamanid for Multidrug- and Rifampicin-Resistant Tuberculosis.

BACKGROUND: There are scarce data on the clinical outcomes of persons retreated with new/companion anti-tuberculosis (TB) drugs for multidrug- and rifampicin-resistant tuberculosis (MDR/RR-TB). We sought to evaluate the efficacy and safety of bedaquiline and delamanid containing regimens among patients with and without prior exposure to the new/companion drugs (bedaquiline, delamanid, linezolid, clofazimine, and fluoroquinolones). METHODS: We conducted a retrospective cohort study among patients with pulmonary MDR/RR-TB in Georgia who received bedaquiline and delamanid combination as a part of a salvage regimen from November 2017 to December 2020 in a programmatic setting. RESULTS: Among 106 persons with a median age of 39.5 years, 44 (41.5%) were previously treated with new/companion TB drugs. Patients with prior exposure to new/companion drugs had higher rates of baseline resistance compared to those without exposure to new/companion TB drugs (bedaquiline 15.2% vs 1.8%, linezolid 22.2% vs 16.7%). Sputum culture conversion rates among patients exposed and not exposed to new/companion drugs were 65.9% vs 98.0%, respectively (P < .001). Among patients with and without prior new/companion TB drug use, favorable outcome rates were 41.0% and 82.3%, respectively (P < .001). Treatment adherence in 32 (30.2%) patients was ≤80%. Five of 21 patients (23.8%) who had a baseline and repeat susceptibility test had acquired bedaquiline resistance. QTC/F prolongation (>500 ms) was rare (2.8%). CONCLUSIONS: Prior exposure to new/companion TB drugs was associated with poor clinical outcomes and acquired drug resistance. Tailoring the TB regimen to each patient's drug susceptibility test results and burden of disease and enhancing adherence support may improve outcomes.

Linezolid use for drug-resistant tuberculosis in Georgia: a retrospective cohort study.

SETTING: Data on the long-term use of linezolid (LZD) in the treatment of drug-resistant pulmonary tuberculosis (DR-PTB) are limited.OBJECTIVE: To assess safety, tolerability and efficacy of LZD-containing regimens for the treatment of DR-PTB in the country of Georgia.DESIGN: A retrospective study was conducted among DR-PTB patients receiving LZD 600 mg/day as part of newly implemented regimens (bedaquiline or delamanid, repurposed and second-line drugs) from July 2014 to October 2015 in programmatic conditions and following WHO recommendations.RESULTS: One hundred mostly male (82%) patients with a median age of 33 years received LZD. Most patients (77%) had previously been treated for TB; 57% had extensively drug-resistant TB. The median duration of LZD use was 503 days (interquartile range 355-616). LZD-associated adverse events occurred in 12 patients, leading to discontinuation in 4 (2 each due to peripheral neuropathy and cytopenias), and dose reduction to 300 mg/day in 6 cases (4 due to peripheral neuropathy and 2 for cytopenias). Almost all patients (95%) achieved culture conversion and 79% had a successful treatment outcomes.CONCLUSION: Treatment regimens including lengthy LZD use showed fairly good safety and tolerability and were associated with high rates of culture conversion and favorable outcomes.

Clinical Outcomes Among Patients With Drug-resistant Tuberculosis Receiving Bedaquiline- or Delamanid-Containing Regimens.

BACKGROUND: Bedaquiline and delamanid are newly available drugs for treating multidrug-resistant tuberculosis (MDR-TB); however, there are limited data guiding their use and no comparison studies. METHODS: We conducted a prospective, observational study among patients with MDR-TB in Georgia who were receiving a bedaquiline- or delamanid-based treatment regimen. Monthly sputum cultures, minimal inhibitory concentration testing, and adverse event monitoring were performed. Primary outcomes were culture conversion rates and clinical outcomes. Targeted maximum likelihood estimation and super learning were utilized to produce a covariate-adjusted proportion of outcomes for each regimen. RESULTS: Among 156 patients with MDR-TB, 100 were enrolled and 95 were receiving a bedaquiline-based (n = 64) or delamanid-based (n = 31) regimen. Most were male (82%) and the median age was 38 years. Rates of previous treatment (56%) and cavitary disease (61%) were high. The most common companion drugs included linezolid, clofazimine, cycloserine, and a fluoroquinolone. The median numbers of effective drugs received among patients on bedaquiline-based (4; interquartile range [IQR], 4-4) and delamanid-based (4; IQR, 3.5-5) regimens were similar. Rates of acquired drug resistance were significantly higher among patients receiving delamanid versus bedaquiline (36% vs 10%, respectively; P < .01). Adjusted rates of sputum culture conversion at 2 months (67% vs 47%, respectively; P = .10) and 6 months (95% vs 74%, respectively; P < .01), as well as more favorable clinical outcomes (96% vs 72%, respectively; P < .01), were higher among patients receiving bedaquiline versus delamanid. CONCLUSIONS: Among patients with MDR-TB, bedaquiline-based regimens were associated with higher rates of sputum culture conversion, more favorable outcomes, and a lower rate of acquired drug resistance versus delamanid-based regimens.