Bedaquiline-containing Regimens Research Articles

QT Prolongation Associated with Administration of Bedaquiline, a Novel Anti-Tuberculosis Drug.

Bedaquiline is a diarylquinoline compound that has recently been introduced and approved for use in the treatment of multidrug-resistant tuberculosis (MDR-TB). Its mechanism of action is inhibition of adenosine triphosphate-synthase. In combination with other antibiotics, bedaquiline-containing regimens administered for 6 months achieve cure rates of roughly 90%, in contrast to the previously used, 24-month-long WHO-recommended regimens for the treatment of MDR-TB. However, since its introduction, concerns have been raised about its effects on QT prolongation and its safety in routine clinical use. We reviewed the published experience regarding bedaquiline use, QT prolongation, and adverse cardiac events when the drug was used alone or in combination. Overall, data are reassuring that bedaquiline use in clinical practice is not associated with an excess of cardiac deaths or other clinically meaningful cardiac events. This review provides reassurance and support for the continued use of bedaquiline in the treatment of MDR-TB.

Bedaquiline versus injectable containing regimens for rifampicin-resistant and multidrug-resistant tuberculosis in a reference center in Brazil – a real-world evidence study using a retrospective design

BackgroundDrug resistance (DR) is one of the several challenges to global tuberculosis (TB) control. The implementation of bedaquiline (BED) for DR-TB after more than 40 years was expected to improve treatment outcomes as well as microbiologic conversion and adverse events (AE) occurrence.MethodsRetrospective cohort study based on secondary data of patients with rifampicin-resistant (RR) or multidrug-resistant (MDR) TB reported to the Outpatient Clinic of Mycobacterial Diseases of the Thorax Diseases Institute – Federal University of Rio de Janeiro - Brazil, between 2016 and 2023. We aimed to evaluate microbiologic conversion, AE and TB treatment outcomes and compare them according to the treatment regimen used for RR/MDR-TB patients under routine conditions [Injectable Containing Regimens (ICR) versus BED Containing Regimens (BCR)]. Logistic regression and survival analysis using Cox regression and Kaplan Meier curve were used for statistical analysis.ResultsOf the 463 DR-TB patients notified during the study period, 297 (64.1%) were included for analysis (ICR = 197 and BCR = 100). Overall AEs were more frequent (83.7 vs. 16.3%, p < 0.001) and occurred earlier in the ICR group (15 days vs. 65 days, p = 0.003). There were no cases of cardiotoxicity requiring interruption of BED treatment. None of the regimens of treatment tested were associated with smear or culture conversion on Cox regression analysis (p = 0.60 and 0.88, respectively). BED-containing regimens were also associated with favorable outcomes in multivariable logistic regression [adjusted odds ratio (aOR) = 2.63, 95% confidence interval (CI)1.36–5.07, p = 0.004], as higher years of schooling, primary drug resistance, and no previous TB treatment. In the survival analysis, BCR was inversely associated with the occurrence of AE during treatment follow-up (aHR 0.24, 95% CI 0.14–0.41, p < 0.001). In addition, TB treatment regimens with BED were also associated with favorable outcomes (aHR 2.41, 95% CI 1.62–3.57, p < 0.001), along with no illicit drug use and primary drug resistance.ConclusionsThe implementation of a fully oral treatment for RR/MDR-TB in a reference center in Brazil was safe and associated with favorable outcomes under routine conditions, despite social, demographic, and behavioral factors that may influence TB treatment completion.

Long-term efficacy and safety of two short standardised regimens for the treatment of rifampicin-resistant tuberculosis (STREAM stage 2): extended follow-up of an open-label, multicentre, randomised, non-inferiority trial

STREAM stage 2 showed that two bedaquiline-containing regimens (a 9-month all-oral regimen and a 6-month regimen with 8 weeks of aminoglycoside) had superior efficacy to a 9-month injectable-containing regimen for rifampicin-resistant tuberculosis up to 76 weeks after randomisation. Our objective in this follow-up analysis was to assess the durability of efficacy and safety, including mortality, at 132 weeks. We report the long-term outcomes from STREAM stage 2, a randomised, phase 3 non-inferiority (10% margin) trial in participants (aged ≥15 years) with rifampicin-resistant tuberculosis without fluoroquinolone or aminoglycoside resistance at 13 clinical sites in seven countries (Ethiopia, Georgia, India, Moldova, Mongolia, South Africa, and Uganda). Participants were randomly assigned 1:2:2:2 (via permuted blocks and stratified by site and HIV status plus CD4 cell count) to the 2011 WHO long regimen (terminated early), a 9-month control regimen, a 9-month oral regimen with bedaquiline (primary comparison), or a 6-month regimen with bedaquiline and 8 weeks of an injectable antituberculous drug. Participants and clinicians were aware of treatment-group assignments, but laboratory staff were masked. The primary outcome, reported previously, was favourable status (negative cultures for Mycobacterium tuberculosis without a preceding unfavourable outcome; any death, bacteriological failure or recurrence, and major treatment change were considered unfavourable) at week 76. Here we report efficacy outcomes at week 132, analysed in the modified intention-to-treat (mITT) population. Safety assessments continued to 132 weeks and were in all participants who received at least one dose of the study regimen. All comparisons used concurrently randomised participants. This trial is registered on ISRCTN (ISRCTN18148631) and is now completed. Between March 28, 2016, and Jan 28, 2020, 588 participants were randomly assigned to the long (n=32), control (n=202), oral (n=211), or 6-month (n=143) treatment regimens; 352 (60%) were male and 236 (40%) were female. Of the 556 participants on the three shorter regimens, 517 were included in the mITT population (187 in control group, 196 in oral group, and 134 in 6-month group) and 465 in the per-protocol analyses. Six additional participants had an unfavourable outcome that occurred between week 76 and the end of efficacy follow-up (one in control group, four in oral group, one in 6-month group). In the mITT population, the proportion of patients with an unfavourable outcome at the end of follow-up was 19·6% (95% CI 14·3 to 24·9) in the oral group and 29·3% (23·3 to 36·5) in the control group (-9·7 percentage points difference [95% CI -18·7 to -1·8]; psuperiority=0·024). An estimated 9·8% (95% CI 4·6 to 14·9) of participants on the 6-month regimen had an unfavourable outcome, which was significantly lower than for those concurrently on the control regimen (32·5% [23·7 to 40·2]; psuperiority<0·0001) or the oral regimen (23·8% [16·9 to 31·1]; psuperiority=0·013). Few serious or severe adverse events were reported after week 76, with no indication of a difference between the regimens. At week 132, treatment-emergent hearing loss was recorded in significantly fewer participants on the oral regimen (7/205; 3%) than the control regimen (16/198; 8%; p=0.041); there was no significant difference in severe hearing loss between the oral regimen (6/139; 4%) and the 6-month regimen (5/143; 4%; p=0·72). Death rates were low: 1·01 (95% CI 0·48 to 2·12) per 100 person-years in participants allocated to bedaquiline (ie, oral and 6-month regimen, n=287) compared with 1·52 (0·63 to 3·66) in participants on the control regimen (n=140; p=0·49). Both of the bedaquiline-containing regimens maintained superiority to the control regimen, without evidence of increased mortality, providing two additional evidence-based treatment options for patients; previous mortality concerns for bedaquiline were not substantiated. US Agency for International Development and Janssen Research & Development.

HIV and body mass index are associated with prolonged corrected QT interval among people with drug-resistant tuberculosis on bedaquiline-containing regimen in Uganda

ObjectivesPeople with drug-resistant tuberculosis (DR-TB) on bedaquiline-containing regimens are at risk for a prolonged corrected QT (QTc) interval but this problem is understudied in low-resource countries. We determined the magnitude and risk factors for QTc interval prolongation among people with DR-TB on bedaquiline-containing regimens at three referral hospitals in Uganda. MethodsUsing retrospectively collected data, we designed a matched case-control study, with cases as participants with prolonged QTc interval and controls as those with normal QTc interval in 1:1. QTc interval prolongation was defined as an increase in QTc interval by 60 milliseconds in electrocardiogram from the baseline or ≥500 milliseconds during follow-up for men and women. Factors associated with cases compared with controls were identified using a multivariable conditional regression analysis at a 5% significance level, reported using odds ratio (OR) and the 95% confidence interval (CI). ResultsOf 153 participants, 39 (25.5%) had a prolonged QTc interval. We matched 30 participants with prolonged QTc interval (cases) with 30 participants with normal QTc interval (controls). Cases and controls were similar in several sociodemographic and clinical characteristics but different regarding the baseline body mass index (BMI), baseline weight, and HIV infection. Increasing BMI (adjusted OR 1.29, 95% CI 1.02-1.63) and HIV infection (adjusted OR 0.27, 95% CI 0.08-0.96) were associated with the cases compared with the controls. ConclusionsWe found a relatively high prevalence of QTc interval prolongation among people with DR-TB on a bedaquiline-containing regimen compared with the prevalence in healthy individuals, with a higher likelihood in those with increasing BMI and a lower likelihood in those with HIV. We recommend routine anthropometric measurements to identify individuals with DR-TB at a high risk for QTc interval prolongation. In addition, tuberculosis/HIV treatment guidelines for people with DR-TB on bedaquiline-containing regimens should include risk assessment for prolonged QTc intervals.

Management of rifampicin-resistant tuberculosis in conflict-affected areas: The case of Iraq.

Since December 2019, the World Health Organization (WHO) has encouraged National Tuberculosis Programs to deprioritize the use of injectable-containing regimens and roll-out all-oral bedaquiline-containing regimens for rifampicin-resistant tuberculosis (RR-TB) treatment. Consequently, Iraq gradually replaced the injectable-containing regimen with an all-oral regimen, including bedaquiline. To assess treatment enrolment and outcomes of both regimens during a transitioning phase in Iraq, where health system services are recovering from decades of war, we conducted a nationwide retrospective cohort study using routinely collected programmatic data for patients enrolled between 2019-2021. We describe treatment enrolment and use logistic regression to identify predictors of unfavorable treatment outcomes (failure, death, or lost to follow-up), including regimen type. Nationwide, a total of 301 RR-TB patients started treatment, of whom 167 concluded treatment. The proportion of patients enrolled on the all-oral regimen increased from 53.2% (50/94) in 2020, to 75.5% (80/106) in 2021. Successful treatment was achieved in 82.1% (32/39) and 63.3% (81/128), for all-oral and injectable-containing regimens respectively. Moreover, the proportion of lost to follow-up was lower among those treated with the all-oral versus the long injectable-containing regimen; respectively 2.6% (1/39) versus 17.9% (23/128: p = 0.02). Unfavorable treatment outcome was associated with male gender (aOR 2.12, 95%CI:1.02-4.43) and age <15 years (vs 30-49 years, aOR 5.80, 95%CI:1.30-25.86). Regimen type (aOR 2.37, 95%CI: 0.91-6.13) was not significantly associated with having an unfavorable treatment outcome. In Iraq, the use of bedaquiline-containing all-oral regimen resulted in a high treatment success and reduced lost to follow-up.

Adaptive evaluation of mHealth and conventional adherence support interventions to optimize outcomes with new treatment regimens for drug-resistant tuberculosis and HIV in South Africa (ADAP-TIV): study protocol for an adaptive randomized controlled trial

BackgroundHighly effective, short-course, bedaquiline-containing treatment regimens for multidrug-resistant tuberculosis (MDR-TB) and integrase strand transfer inhibitor (INSTI)-containing fixed dose combination antiretroviral therapy (ART) have radically transformed treatment for MDR-TB and HIV. However, without advances in adherence support, we may not realize the full potential of these therapeutics. The primary objective of this study is to compare the effect of adherence support interventions on clinical and biological endpoints using an adaptive randomized platform.MethodsThis is a prospective, adaptive, randomized controlled trial comparing the effectiveness of four adherence support strategies on a composite clinical outcome in adults with MDR-TB and HIV initiating bedaquiline-containing MDR-TB treatment regimens and receiving ART in KwaZulu-Natal, South Africa. Trial arms include (1) enhanced standard of care, (2) psychosocial support, (3) mHealth using cellular-enabled electronic dose monitoring, and (4) combined mHealth and psychosocial support. The level of support will be titrated using a differentiated service delivery (DSD)-informed assessment of treatment support needs. The composite primary outcome will include survival, negative TB culture, retention in care, and undetectable HIV viral load at month 12. Secondary outcomes will include individual components of the primary outcome and quantitative evaluation of adherence on TB and HIV treatment outcomes.DiscussionThis trial will evaluate the contribution of different modes of adherence support on MDR-TB and HIV outcomes with WHO-recommended all-oral MDR-TB regimens and ART in a high-burden operational setting. We will also assess the utility of a DSD framework to pragmatically adjust levels of MDR-TB and HIV treatment support.Trial registrationClinicalTrials.gov NCT05633056. Registered on 1 December 2022

Efficacy and safety of the all-oral bedaquiline-containing regimen as treatment for pediatric multidrug/rifampicin-resistant tuberculosis: a multicenter, retrospective, cohort study

ABSTRACT Objective The study aimed to observe the efficacy and safety of an all-oral bedaquiline (BDQ)-containing regimen for pediatric multidrug/rifampicin-resistant tuberculosis (MDR/RR-TB) through a multicenter, retrospective study in China. Methods In the study, pediatric patients receiving all-oral BDQ-containing regimen (BDQ group) with clinical matched control group were included, the control group received an injection-containing regimen. The treatment outcomes and the incidence of adverse events (AEs) were compared and analyzed. Results 79 pediatric patients were enrolled, including 37 cases in BDQ group and 42 cases in the control group, the median age was 12 {8–16} and 11 {9–15} in both groups respectively. Favorable treatment outcome and cure rate in BDQ group were significantly higher than those in control group (100%vs 83.3%, p 0.03; 94.6%vs 63.3%, p 0.00). Median time of sputum culture conversion in BDQ group was significantly shorter than that in the control group (4 weeks vs 8 weeks, p 0.00). The incidence of AEs in the BDQ group was significantly less than that in the control group (48.6% vs 71.4%, p 0.03). No AEs leading to treatment discontinuation of BDQ occurred. Conclusions The all-oral BDQ-containing regimens may be effective and safe in the Chinese pediatric population.

Bedaquiline in the postoperative period of complex therapy of tuberculosis

Introduction. The experience of domestic phthisiatry, which has been using bedaquiline for more than 10 years, testifies to the efficacy and safety of the drug for the treatment of drug-resistant forms of tuberculosis. At the present stage, the evaluation of the effect and safety of bedaquiline in the postoperative stage of chemotherapy, including patients with HIV/tuberculosis co-infection, becomes the most relevant.Aim. To evaluate the results of bedaquiline application in the postoperative stage of complex tuberculosis therapy.Materials and methods. Results of a retrospective study of medical records of 57 patients. The inclusion criterion was the surgery performed for tuberculosis and the presence of bedaquiline in the postoperative chemotherapy regimen. Frequency of tuberculosis progression 1 month after surgery was evaluated as an efficacy criterion. The frequency of QTc interval prolongation with clinical manifestations, frequency and nature of hepatotoxic reactions were evaluated as the drug safety criterion.Results. In the absolute majority of patients – 54 (94.7%) postoperative period, during which bedaquiline was used, proceeded without complications. Cases of tuberculosis progression were observed only in patients with severe concomitant diseases. Undesirable side effects on bedaquiline were observed in 9 (15.8%) patients, the absolute majority of patients resumed taking the drug in full after drug correction. The average duration of bedaquiline prescription was 282 ± 5 doses.Conclusions. The use of bedaquiline in the postoperative period increases the effectiveness of complex therapy and prevents progression of tuberculosis and according to our data should be regarded as safe. Administration of bedaquiline in patients with HIV/tuberculosis co-infection also contributes to the positive result of the therapy. Repeated courses of bedaquiline after surgical intervention, including in patients with HIV/tuberculosis co-infection, prevent progression of tuberculosis in the postoperative period. The tolerability of the bedaquiline-containing regimen in this category of patients, including long courses of more than 24 weeks, was assessed as quite satisfactory.

Bedaquiline resistance in patients with drug-resistant tuberculosis in Cape Town, South Africa: a retrospective longitudinal cohort study

Bedaquiline is a life-saving tuberculosis drug undergoing global scale-up. People at risk of weak tuberculosis drug regimens are a priority for novel drug access despite the potential source of Mycobacterium tuberculosis-resistant strains. We aimed to characterise bedaquiline resistance in individuals who had sustained culture positivity during bedaquiline-based treatment. We did a retrospective longitudinal cohort study of adults (aged ≥18 years) with culture-positive pulmonary tuberculosis who received at least 4 months of a bedaquiline-containing regimen from 12 drug-resistant tuberculosis treatment facilities in Cape Town, South Africa, between Jan 20, 2016, and Nov 20, 2017. Sputum was programmatically collected at baseline (ie, before bedaquiline initiation) and each month to monitor treatment response per the national algorithm. The last available isolate from the sputum collected at or after 4 months of bedaquiline was designated the follow-up isolate. Phenotypic drug susceptibility testing for bedaquiline was done on baseline and follow-up isolates in MGIT960 media (WHO-recommended critical concentration of 1 μg/mL). Targeted deep sequencing for Rv0678, atpE, and pepQ, as well as whole-genome sequencing were also done. In total, 40 (31%) of 129 patients from an estimated pool were eligible for this study. Overall, three (8%) of 38 patients assessable by phenotypic drug susceptibility testing for bedaquiline had primary resistance, 18 (47%) gained resistance (acquired or reinfection), and 17 (45%) were susceptible at both baseline and follow-up. Several Rv0678 and pepQ single-nucleotide polymorphisms and indels were associated with resistance. Although variants occurred in Rv0676c and Rv1979c, these variants were not associated with resistance. Targeted deep sequencing detected low-level variants undetected by whole-genome sequencing; however, none were in genes without variants already detected by whole-genome sequencing. Patients with baseline fluoroquinolone resistance, clofazimine exposure, and four or less effective drugs were more likely to have bedaquiline-resistant gain. Resistance gain was primarily due to acquisition; however, some reinfection by resistant strains occurred. Bedaquiline-resistance gain, for which we identified risk factors, was common in these programmatically treated patients with sustained culture positivity. Our study highlights risks associated with implementing life-saving new drugs and shows evidence of bedaquiline-resistance transmission. Routine drug susceptibility testing should urgently accompany scale-up of new drugs; however, rapid drug susceptibility testing for bedaquiline remains challenging given the diversity of variants observed. Doris Duke Charitable Foundation, US National Institute of Allergy and Infectious Diseases, South African Medical Research Council, National Research Foundation, Research Foundation Flanders, Stellenbosch University Faculty of Medicine Health Sciences, South African National Research Foundation, Swiss National Science Foundation, and Wellcome Trust.

THE EFFECTIVENESS AND SAFETY OF BEDAQUILINE-CONTAINING REGIMENS IN THE TREATMENT OF PATIENTS WITH MULTI-DRUG RESISTANT TUBERCULOSIS (MDR-TB): A SYSTEMATIC LITERATURE REVIEW

Objective: MDR-TB is a life-threatening infectious disease. In recent years, RR/MDR TB sufferers have increased by 10% from 186,883 patients in 2018 to 206,030 in 2019. The success rate of treatment for RR/MDR-TB patients only reaches 57% globally. WHO has recommended bedaquiline for treatment of MDR-TB as the first drug in an all-oral regimen designed to maximize treatment outcomes. Purpose: to describe the efficacy and safety of a bedaquiline-containing regimen for the treatment of MDR-TB. Methods: Pubmed, Science Direct, and Embase online databases were used to obtain data published in the last five years where literature searches were carried out independently by researchers. The keywords used in this search are combined with the Boolean operator "AND", namely (bedaquiline) AND (multidrug resistant) AND (effectiveness). Results: Eight studies met the inclusion criteria, demonstrating a higher conversion rate of sputum cultures on the bedaquiline containing regimen between 74%-95.8% with a mean time to culture conversion between 39 days-3 months. The majority of studies reported an adverse effect of QT prolongation in patients treated with bedaquiline. Conclusion: This systematic review showed that bedaquiline is effective and safe for use in the treatment of MDR-TB. However, serious side effects of QT prolongation occurred in some respondents who were treated with bedaquiline, so an effective and efficient monitoring and surveillance system is needed to ensure best practice in the treatment of MDR-TB.

Outcomes of bedaquiline-containing regimen in the treatment of adults with drug-resistant tuberculosis in a tertiary care center in Rajasthan.

The emergence of drug-resistant strains of Mycobacterium tuberculosis has become a significant public health problem and has led to a setback in the efforts to end tuberculosis (TB) worldwide. The longer duration, heavier pill load, and higher toxicity profile of drug-resistant TB regimens compared to those for drug-susceptible TB lead to reduced adherence and worse treatment results, including mortality. This study was conducted to estimate treatment outcomes and adverse effects in patients with drug-resistant TB on a bedaquiline-containing regimen. Patients after the pre-treatment evaluation were enrolled in a bedaquiline-containing regimen. These patients were followed up for 18 months, and the final outcome was assessed along with the adverse effects. It was found that 49 (84.4%) patients achieved culture conversion by 3 months, 54 (93.1%) achieved culture conversion by 6 months, 52 (83.81%) had favorable outcomes (cured, treatment completed), and 10 had unfavorable outcomes (died, lost to follow-up, failed). Coupled with gradually increasing trends in success rates since 2012, lesser failure rates and fewer concerns regarding grave adverse effects are a silver lining in the cloud of increasing burden and widening resistance patterns. More funding has to be directed towards ensuring adherence and finding high-risk individuals to expedite the achievement of sustainable development goals.

Comparative safety of bedaquiline and delamanid in patients with multidrug resistant tuberculosis: A nationwide retrospective cohort study.

Bedaquiline and delamanid were recently approved for multidrug resistant tuberculosis (MDR-TB). Bedaquiline carries a black box warning of increased risk of death compared to the placebo arm, and there is a need to establish the risks of QT prolongation and hepatotoxicity for bedaquiline and delamanid. We retrospectively analyzed data of MDR-TB patients retrieved from the South Korea national health insurance system database (2014-2020) to assess the risks of all-cause death, long QT-related cardiac event, and acute liver injury associated with bedaquiline or delamanid, compared with conventional regimen. Cox proportional hazards models were used to estimate hazard ratios (HR) with 95% confidence intervals (CI). Stabilized inverse probability of treatment weighting based on propensity score was used to balance characteristics between the treatment groups. Of 1998 patients, 315 (15.8%) and 292 (14.6%) received bedaquiline and delamanid, respectively. Compared with conventional regimen, bedaquiline and delamanid did not increase risk of all-cause death at 24-month (HR 0.73 [95% CI, 0.42-1.27] and 0.89 [0.50-1.60], respectively). Bedaquiline-containing regimen increased risk of acute liver injury (1.76 [1.31-2.36]), while delamanid-containing regimen increased risk of long QT-related cardiac events (2.38 [1.05-3.57]) within 6 months of treatment. This study adds to the emerging evidence refuting the higher mortality rate observed in the bedaquiline trial population. Association between bedaquiline and acute liver injury needs careful interpretation considering for other background hepatotoxic anti-TB drugs. Our finding on delamanid and long QT-related cardiac events suggest careful risk-benefit assessment in patients with pre-existing cardiovascular disease.

Сlinical and economic evaluation of various etiotropic chemotherapy regimens in patients with respiratory tuberculosis with multidrug and extensively drug resistance

Objective: analysis of clinical and economic efficiency of various etiotropic chemotherapy regimes in patients with respiratory tuberculosis with multidrug- and extensively drug-resistant (MDR and XDR) pathogen using the pharmacoeconomic modeling method (Markov model).Material and methods. A single-centre, observational, retrospective, cohort study was performed, which included patients who received treatment in clinics and affiliated organizations of the main Moscow tuberculosis institution during 2014–2019 regarding respiratory tuberculosis with the MDR/XDR pathogen. The data of 1387 patients were analysed, of which 1093 patients received “optimized basic regimen” (OBR) in accordance with the Federal Clinical Recommendations of 2015, 294 patients received etiotropic therapy in accordance with the recommendations of the World Health Organization of 2018–2019. To evaluate economic efficiency, the pharmacoeconomic costeffectiveness analysis and pharmacoeconomic modeling were used. When assessing the economic costs of treatment, the direct costs (medical and non-medical) were taken into account.Results. The study results showed that 68.4% of patients in the group with bedaquiline-containing chemotherapy regimens reached the outcome of “treatment successfully completed” (patient was cured or transfered into the III group of dispensary follow-up) compared to 51.8% in the OBR group. The use of “new” etiotropic therapy regimens is most economically justified in patients with ХDR-tuberculosis with repeated treatment courses: incremental cost-effectiveness ratios (ICER) were 24,530.20 and 21,526.50 rubles per 1 patient. Markov model was developed, transitions from one state to another were evaluated according to the results of clinical observations during the first 2 years of research.Conclusion. The use of the dynamic model of the patient state made it possible to refine the estimates of the effectiveness of the compared etiotropic chemotherapy regimens for tuberculosis with MDR/XDR pathogen. Based on the results of modeling the dynamics of patients in the interval of 2 to 10 years of treatment, the use of “new” regimens provides a significant increase in the proportion of treatment success (by 16.1–29.8% in different groups of patients and at different times), a decrease in mortality (by 6.1–11.0%), and in the proportion of those who interrupted treatment (by 8.0–21.8%) in comparison with OBR.

Population pharmacokinetics and model-based dosing evaluation of bedaquiline in multidrug-resistant tuberculosis patients.

Aims: Bedaquiline is now recommended to all patients in the treatment of multidrug-resistant tuberculosis (MDR-TB) using standard dosing regimens. As the ability to measure blood drug concentrations is very limited, little is known about drug exposure and treatment outcome. Thus, this study aimed to model the population pharmacokinetics as well as to evaluate the currently recommended dosage. Methodology: A bedaquiline population pharmacokinetic (PK) model was developed based on samples collected from the development cohort before and 1, 2, 3, 4, 5, 6, 8, 12, 18, and 24h after drug intake on week 2 and week 4 of treatment. In a prospective validation cohort of patients with MDR-TB, treated with bedaquiline-containing standardized regimen, drug exposure was assessed using the developed population PK model and thresholds were identified by relating to 2-month and 6-month sputum culture conversion and final treatment outcome using classification and regression tree analysis. In an exploratory analysis by the probability of target attainment (PTA) analysis, we evaluated the recommended dosage at different MIC levels by Middlebrook 7H11 agar dilution (7H11). Results: Bedaquiline pharmacokinetic data from 55 patients with MDR-TB were best described by a three-compartment model with dual zero-order input. Body weight was a covariate of the clearance and the central volume of distribution, albumin was a covariate of the clearance. In the validation cohort, we enrolled 159 patients with MDR-TB. The 7H11 MIC mode (range) of bedaquiline was 0.06mg (0.008-0.25mg/L). The study participants with AUC0-24h/MIC above 175.5 had a higher probability of culture conversion after 2-month treatment (adjusted relative risk, aRR:16.4; 95%CI: 5.3-50.4). Similarly, those with AUC0-24h/MIC above 118.2 had a higher probability of culture conversion after 6-month treatment (aRR:20.1; 95%CI: 2.9-139.4), and those with AUC0-24h/MIC above 74.6 had a higher probability of successful treatment outcome (aRR:9.7; 95%CI: 1.5-64.8). Based on the identified thresholds, simulations showed that the WHO recommended dosage (400mg once daily for 14 days followed by 200mg thrice weekly) resulted in PTA >90% for the majority of isolates (94%; MICs ≤0.125mg/L). Conclusion: We established a population PK model for bedaquiline in patients with MDR-TB in China. Based on the thresholds and MIC distribution derived in a clinical study, the recommended dosage of bedaquiline is sufficient for the treatment of MDR-TB.

Outcomes of patients undergoing lung resection for drug-resistant TB and the prognostic significance of pre-operative positron emission tomography/computed tomography (PET/CT) in predicting treatment failure.

Surgery remains an adjunctive treatment for drug-resistant tuberculosis (DR-TB) treatment failure despite the use of bedaquiline. However, there are few data about the role of surgery when combined with newer drugs. There are no outcome data from TB endemic countries, and the prognostic significance of pre-operative PET-CT remains unknown. We performed a prospective observational study of 57 DR-TB patients referred for surgery at Groote Schuur Hospital between 2010 and 2016. PET-CT was performed if there was nodal disease or disease outside the area of planned resection but did not influence treatment decisions. 24-month treatment success post-surgery (cure or treatment completion), including all-cause mortality, was determined. 35/57 (61.4%) patients (median age 40 years; 26% HIV-infected) underwent surgery and 22/57 (38.6%) did not (11 patients were deemed unsuitable due to bilateral cavitary disease and 11 patients declined surgery). Treatment failure was significantly lower in those who underwent surgery compared to those eligible but declined surgery [15/35 (43%) versus 11/11 (100%); relative risk 0.57 (0.42-0.76); p<0.01). In patients treated with surgery, a post-operative regimen containing bedaquiline was associated with a lower odds of treatment failure [OR (95%CI) 0.06 (0.00-0.48); p=0.007]. Pre-operative PET-CT (n=25) did not predict treatment outcome. Resectional surgery for DR-TB combined with chemotherapy was associated with significantly better outcomes than chemotherapy alone. A post-operative bedaquiline-containing regimen was associated with improved outcome; however, this finding may have been confounded by higher use of bedaquiline and less loss to follow-up in the surgical group. However, PET-CT had no prognostic value. These data inform clinical practice in TB-endemic settings. This work was supported by the South African MRC (RFA-EMU-02-2017) and the EDCTP (TMA-2015SF-1043 & TMA- 1051-TESAII).

Economic evaluation of shortened, bedaquiline-containing treatment regimens for rifampicin-resistant tuberculosis (STREAM stage 2): a within-trial analysis of a randomised controlled trial

The STREAM stage 2 trial assessed two bedaquiline-containing regimens for rifampicin-resistant tuberculosis: a 9-month all-oral regimen and a 6-month regimen containing an injectable drug for the first 2 months. We did a within-trial economic evaluation of these regimens. STREAM stage 2 was an international, phase 3, non-inferiority randomised trial in which participants with rifampicin-resistant tuberculosis were randomly assigned (1:2:2:2) to the 2011 WHO regimen (terminated early), a 9-month injectable-containing regimen (control regimen), a 9-month all-oral regimen with bedaquiline (oral regimen), or a 6-month regimen with bedaquiline and an injectable for the first 2 months (6-month regimen). We prospectively collected direct and indirect costs and health-related quality of life data from trial participants until week 76 of follow-up. Cost-effectiveness of the oral and 6-month regimens versus control was estimated in four countries (oral regimen) and two countries (6-month regimen), using health-related quality of life for cost-utility analysis and trial efficacy for cost-effectiveness analysis. This trial is registered with ISRCTN, ISRCTN18148631. 300 participants were included in the economic analyses (Ethiopia, 61; India, 142; Moldova, 51; Uganda, 46). In the cost-utility analysis, the oral regimen was not cost-effective in Ethiopia, India, Moldova, and Uganda from either a provider or societal perspective. In Moldova, the oral regimen was dominant from a societal perspective. In the cost-effectiveness analysis, the oral regimen was likely to be cost-effective from a provider perspective at willingness-to-pay thresholds per additional favourable outcome of more than US$4500 in Ethiopia, $1900 in India, $3950 in Moldova, and $7900 in Uganda, and from a societal perspective at thresholds of more than $15 900 in Ethiopia, $3150 in India, and $4350 in Uganda, while in Moldova the oral regimen was dominant. In Ethiopia and India, the 6-month regimen would cost tuberculosis programmes and participants less than the control regimen and was highly likely to be cost-effective in both cost-utility analysis and cost-effectiveness analysis. Reducing the bedaquiline price from $1·81 to $1·00 per tablet made the oral regimen cost-effective in the provider-perspective cost-utility analysis in India and Moldova and dominate over the control regimen in the provider-perspective cost-effectiveness analysis in India. At current costs, the oral bedaquiline-containing regimen for rifampicin-resistant tuberculosis is unlikely to be cost-effective in many low-income and middle-income countries. The 6-month regimen represents a cost-effective alternative if injectable use for 2 months is acceptable. USAID and Janssen Research & Development.

Costs and import costs of past, present, and future TB drug regimens: a case study for Karakalpakstan, Uzbekistan.

Tuberculosis (TB) drugs and their import are costly. We assessed how shorter TB drug regimens, which were non-inferior or superior in recent TB trials, can affect the costs for purchasing and importing TB drugs. We estimated the drug costs and import costs of 39 longer and shorter TB drug regimens using TB drug prices from the Global Drug Facility and import cost estimates for a TB program in Karakalpakstan, Uzbekistan. Drug regimens from recent TB trials were compared with TB drug regimens following present or past World Health Organization recommendations. We estimated an import cost of $4.19 and a drug cost of $43 per standard 6-month drug-sensitive (DS)-TB regimen. A new 17-week DS-TB regimen from the TBTC Study 31 currently requires more tablets and is more expensive to import ($6.08) and purchase ($233). The TB program can substantially decrease import costs ($2.26-14) and drug costs ($391-2308) per multidrug-resistant (MDR)-TB regimen when using new 6-month or shorter drug regimens from the Nix-TB, NExT, TB PRACTECAL, ZeNix, or BEAT TB trials instead of 9-20-month regimens with import costs of $9.96-507 and drug costs of $354-15028. For a commonly used 20-month all-oral, bedaquiline-containing MDR-TB regimen, we estimated costs of $41 for drug import and $1773 for drug purchase. The implementation of a new and shorter DS-TB regimen may increase the costs for drug purchase and import. The implementation of new and shorter MDR-TB regimens may decrease the costs for drug purchase and/or drug import.

Bedaquiline safety, efficacy, utilization and emergence of resistance following treatment of multidrug-resistant tuberculosis patients in South Africa: a retrospective cohort analysis

BackgroundThis retrospective cohort study assessed benefits and risks of bedaquiline treatment in multidrug-resistant-tuberculosis (MDR-TB) combination therapy by evaluating safety, effectiveness, drug utilization and emergence of resistance to bedaquiline.MethodsData were extracted from a register of South African drug-resistant-tuberculosis (DR-TB) patients (Electronic DR-TB Register [EDRWeb]) for newly diagnosed patients with MDR-TB (including pre-extensively drug-resistant [XDR]-TB and XDR-TB and excluding rifampicin-mono-resistant [RR]-TB, as these patients are by definition not multidrug-resistant), receiving either a bedaquiline-containing or non-bedaquiline-containing regimen, at 14 sites in South Africa. Total duration of treatment and follow-up was up to 30 months, including 6 months’ bedaquiline treatment. WHO treatment outcomes within 6 months after end-of-treatment were assessed in both patient groups. Longer term mortality (up to 30 months from treatment start) was evaluated through matching to the South African National Vital Statistics Register. Multivariable Cox proportional hazards analyses were used to predict association between receiving a bedaquiline-containing regimen and treatment outcome.ResultsData were extracted from EDRWeb for 5981 MDR-TB patients (N = 3747 bedaquiline-treated; N = 2234 non-bedaquiline-treated) who initiated treatment between 2015 and 2017, of whom 40.7% versus 80.6% had MDR-TB. More bedaquiline-treated than non-bedaquiline-treated patients had pre-XDR-TB (27.7% versus 9.5%) and XDR-TB (31.5% versus 9.9%) per pre-2021 WHO definitions. Most patients with treatment duration data (94.3%) received bedaquiline for 6 months. Treatment success (per pre-2021 WHO definitions) was achieved in 66.9% of bedaquiline-treated and 49.4% of non-bedaquiline-treated patients. Death was reported in fewer bedaquiline-treated (15.4%) than non-bedaquiline-treated (25.6%) patients. Bedaquiline-treated patients had increased likelihood of treatment success and decreased risk of mortality versus non-bedaquiline-treated patients. In patients with evaluable drug susceptibility testing data, 3.5% of bedaquiline-susceptible isolates at baseline acquired phenotypic resistance. Few patients reported bedaquiline-related treatment-emergent adverse events (TEAEs) (1.8%), TEAE-related bedaquiline discontinuations (1.4%) and QTcF values > 500 ms (2.5%) during treatment.ConclusionData from this large cohort of South African patients with MDR-TB showed treatment with bedaquiline-containing regimens was associated with survival and effectiveness benefit compared with non-bedaquiline-containing regimens. No new safety signals were detected. These data are consistent with the positive risk–benefit profile of bedaquiline and warrant continued implementation in combination therapy for MDR-TB treatment.

Evaluation of two short standardised regimens for the treatment of rifampicin-resistant tuberculosis (STREAM stage 2): an open-label, multicentre, randomised, non-inferiority trial

The STREAM stage 1 trial showed that a 9-month regimen for the treatment of rifampicin-resistant tuberculosis was non-inferior to the 20-month 2011 WHO-recommended regimen. In STREAM stage 2, we aimed to compare two bedaquiline-containing regimens with the 9-month STREAM stage 1 regimen. We did a randomised, phase 3, non-inferiority trial in 13 hospital clinics in seven countries, in individuals aged 15 years or older with rifampicin-resistant tuberculosis without fluoroquinolone or aminoglycoside resistance. Participants were randomly assigned 1:2:2:2 to the 2011 WHO regimen (terminated early), a 9-month control regimen, a 9-month oral regimen with bedaquiline (primary comparison), or a 6-month regimen with bedaquiline and 8 weeks of second-line injectable. Randomisations were stratified by site, HIV status, and CD4 count. Participants and clinicians were aware of treatment-group assignments, but laboratory staff were masked. The primary outcome was favourable status (negative cultures for Mycobacterium tuberculosis without a preceding unfavourable outcome) at 76 weeks; any death, bacteriological failure or recurrence, and major treatment change were considered unfavourable outcomes. All comparisons used groups of participants randomly assigned concurrently. For non-inferiority to be shown, the upper boundary of the 95% CI should be less than 10% in both modified intention-to-treat (mITT) and per-protocol analyses, with prespecified tests for superiority done if non-inferiority was shown. This trial is registered with ISRCTN, ISRCTN18148631. Between March 28, 2016, and Jan 28, 2020, 1436 participants were screened and 588 were randomly assigned. Of 517 participants in the mITT population, 133 (71%) of 187 on the control regimen and 162 (83%) of 196 on the oral regimen had a favourable outcome: a difference of 11·0% (95% CI 2·9-19·0), adjusted for HIV status and randomisation protocol (p<0·0001 for non-inferiority). By 76 weeks, 108 (53%) of 202 participants on the control regimen and 106 (50%) of 211 allocated to the oral regimen had an adverse event of grade 3 or 4; five (2%) participants on the control regimen and seven (3%) on the oral regimen had died. Hearing loss (Brock grade 3 or 4) was more frequent in participants on the control regimen than in those on the oral regimen (18 [9%] vs four [2%], p=0·0015). Of 134 participants in the mITT population who were allocated to the 6-month regimen, 122 (91%) had a favourable outcome compared with 87 (69%) of 127 participants randomly assigned concurrently to the control regimen (adjusted difference 22·2%, 95% CI 13·1-31·2); six (4%) of 143 participants on the 6-month regimen had grade 3 or 4 hearing loss. Both bedaquiline-containing regimens, a 9-month oral regimen and a 6-month regimen with 8 weeks of second-line injectable, had superior efficacy compared with a 9-month injectable-containing regimen, with fewer cases of hearing loss. USAID and Janssen Research & Development.

Development and Validation of a Nomogram for Prediction of QT Interval Prolongation in Patients Administered Bedaquiline-Containing Regimens in China: a Modeling Study.

Corrected QT duration (QTc) interval prolongation is the most frequent adverse event associated with bedaquiline (BDQ) use. It may affect the safety of antituberculosis therapy, which leads to the consequent demands of needing to monitor during therapy. Our objective was to establish and validate a prediction model for estimating the risk of QTc prolongation after initiation of BDQ-containing regimens to multidrug-resistant tuberculosis (MDR-TB) patients. We constructed an individualized nomogram model based on baseline demographic and clinical characteristics of each patient within a Chinese cohort during BDQ treatment. The generalizability of this model was further validated through use of externally acquired data obtained from Beijing Chest Hospital from 2019 to 2020. Overall, 1,215 and 165 patients were included in training and external validation cohorts, respectively, whereby during anti-TB drug treatment, QTc prolongation was observed in 273 (22.5%) and 29 (17.6%) patients within these respective cohorts, for whom QTc values were >500 ms in 86 (31.5%) and 10 (34.7%) patients, respectively. Next, a total of four Cox proportional hazards models were created and assessed; then, nomograms derived from the models were plotted based on independent predictors of clofazimine, baseline QTc interval, creatinine, extensive drug-resistance (XDR), moxifloxacin, levofloxacin, and sex. Nomogram analysis revealed concordance index values of 0.723 (95% confidence interval [CI], 0.695 to 0.750) for the training cohort and 0.710 (95% CI, 0.627 to 0.821) for the external validation cohort, thus indicating relatively fair agreement between predicted and observed probabilities of QTc prolongation occurrence based on data obtained during 8-week, 16-week, and 24-week anti-TB treatment of both cohorts. Taken together, results obtained using these models demonstrated that coadministration of clofazimine and abnormal baseline QTc interval significantly contributed to QTc prolongation development during MDR-TB patient treatment with a BDQ-containing anti-TB treatment regimen.