Bedaquiline-containing Regimens Research Articles

Bedaquiline: A Novel Diarylquinoline for Multidrug-Resistant Pulmonary Tuberculosis.

A new drug Bedaquiline, a diarylquinoline agent has been approved by the Food and Drug Administration for the treatment of pulmonary multidrug-resistant tuberculosis. It has been given approval for use along with the basic regimen with only conditional access through the National Program for tuberculosis in India. The major problem with existing antitubercular drugs used for the treatment of multi-drug resistant tuberculosis is antimicrobial resistance, less efficacy, and poor side effect profile. Bedaquiline might be a solution to these issues. Bedaquiline is a first of its class drug with a unique and specific mechanism of action. It inhibits mycobacterial adenosine triphosphate (ATP) synthase's proton pump. There are many randomized clinical trials and cohort studies that reported a higher culture conversion rate with bedaquiline treatment as compared to the control group. Many meta-analyses and systematic reviews have reported higher culture conversion rate, higher cure rate, and lower mortality rate in patients with drug-resistant tuberculosis treated with a bedaquiline-containing regimen. Here is a detailed drug profile of bedaquiline to help health care workers treat tuberculosis patients.Keywords:

Effectiveness and safety of bedaquiline-containing regimens for treatment on patients with refractory RR/MDR/XDR-tuberculosis: a retrospective cohort study in East China

ObjectiveRefractory rifampicin-resistant/multidrug resistant/extensively-drug resistant tuberculosis (RR/MDR/XDR-TB) were defined as patients infected with Mycobacterium tuberculosis (MTB) resistant to rifampicin(RR-TB), or at least resistant to rifampicin and isoniazid (MDR-TB) or added resistant to fluoroquinolones (FQs) and one of second line injectable agents (XDR-TB), a patient for whom an effective regimen (fewer than 4 effective agents due to adverse events (AEs) or multiple drug resistances) cannot be developed. To compare the effectiveness and safety of bedaquiline (BDQ)-containing and BDQ-free regimens for treatment of patients with refractory RR/MDR/XDR-TB.MethodsPatients with refractory RR/MDR/XDR-TB receiving BDQ-containing regimens (BDQ group, n = 102) and BDQ-free regimens (non-BDQ group, n = 100) satisfied with included criteria were strictly included in this retrospective historical control study across East China. Culture conversion, treatment outcome, cavity closing rate, and AEs were compared between two groups.ResultsThe baseline characteristics involved all possible aspects of patients were well balanced between two groups (p > 0.05). Culture conversion rates in the BDQ group at month 3 (89.2% vs. 66.0%), month 6 (90.2% vs 72.0%), month 9 (91.2% vs. 66.0%), and month 12 (94.1% vs 65.0%) were all significantly higher than those in non-BDQ group (p < 0.001). Similar results were observed in the cavity closing rate at month 9 (19.6% vs 8.0%, p = 0.0) and month 12 (39.2% vs 15.0%, p < 0.001). Patients receiving BDQ-containing regimens had more treatment success than those receiving BDQ-free regimens (p < 0.001; cure rate, 69.6% vs. 45.0%; complete the treatment, 22.5% vs. 18.0%; treatment success, 92.2% vs. 63.0%); the use of BDQ and combined with Linezolid or Clofazimine or Cycloserine were identified as independent predictors of treatment success and no culture reversion (P < 0.05). AEs were similarly reported in 26.5% of patients in the BDQ group and 19.0% in the non-BDQ group (p = 0.2).ConclusionsBDQ-containing regimens resulted in better treatment outcomes and similar safety relative to BDQ-free regimens for patients with refractory pulmonary RR/MDR/XDR-TB.

Treatment outcomes 24 months after initiating short, all-oral bedaquiline-containing or injectable-containing rifampicin-resistant tuberculosis treatment regimens in South Africa: a retrospective cohort study

SummaryBackgroundThere is a need for short and safe all-oral treatment of rifampicin-resistant tuberculosis. We compared outcomes up to 24 months after treatment initiation for patients with rifampicin-resistant tuberculosis in South Africa treated with a short, all-oral bedaquiline-containing regimen (bedaquiline group), or a short, injectable-containing regimen (injectable group).MethodsPatients with rifampicin-resistant tuberculosis, aged 18 years or older, eligible for a short regimen starting treatment between Jan 1 and Dec 31, 2017, with a bedaquiline-containing or WHO recommended injectable-containing treatment regimen of 9–12 months, registered in the drug-resistant tuberculosis database (EDRWeb), and with known age, sex, HIV status, and national identification number were eligible for study inclusion; patients receiving linezolid, carbapenems, terizidone or cycloserine, delamanid, or para-aminosalicylic acid were excluded. Bedaquiline was given at a dose of 400 mg once daily for two weeks followed by 200 mg three times a week for 22 weeks. To compare regimens, patients were exactly matched on HIV and ART status, previous tuberculosis treatment history, and baseline acid-fast bacilli smear and culture result, while propensity score matched on age, sex, province of treatment, and isoniazid-susceptibility status. We did binomial linear regression to estimate adjusted risk differences (aRD) and 95% CIs for 24-month outcomes, which included: treatment success (ie, cure or treatment completion without evidence of recurrence) versus all other outcomes, survival versus death, disease free survival versus survival with treatment failure or recurrence, and loss to follow-up versus all other outcomes.FindingsOverall, 1387 (14%) of 10152 patients with rifampicin-resistant tuberculosis treated during 2017 met inclusion criteria; 688 in the bedaquiline group and 699 in the injectable group. Four patients (1%) had treatment failure or recurrence, 44 (6%) were lost to follow-up, and 162 (24%) died in the bedaquiline group, compared with 17 (2%), 87 (12%), and 199 (28%), respectively, in the injectable group. In adjusted analyses, treatment success was 14% (95% CI 8–20) higher in the bedaquiline group than in the injectable group (70% vs 57%); loss to follow-up was 4% (1–8) lower in the bedaquiline group (6% vs 12%); and disease-free survival was 2% (0–5) higher in the bedaquiline group (99% vs 97%). The bedaquiline group had 8% (4–11) lower risk of mortality during treatment (17·0% vs 22·4%), but there was no difference in mortality post-treatment.InterpretationPatients in the bedaquiline group experienced significantly higher rates of treatment success at 24 months. This finding supports the use of short bedaquiline-containing regimens in eligible patients.FundingWHO Global TB Programme.TranslationFor the French translation of the abstract see Supplementary Materials section.

Acquired bedaquiline resistance during the treatment of drug-resistant tuberculosis: a systematic review.

BackgroundDrug-resistant tuberculosis (DR-TB) is considered to be a public health threat and is difficult to cure, requiring a lengthy treatment with potent, potentially toxic drugs. The novel antimicrobial agent bedaquiline has shown promising results for patients with DR-TB, improving the rate of culture conversion and reducing TB-related mortality. However, increasing numbers of cases with acquired bedaquiline resistance (ABR) have been reported in recent years.MethodsThis systematic review aimed to assess the frequency of ABR and characteristics of patients acquiring it. Studies showing data on sequential bedaquiline drug-susceptibility testing in patients treated with a bedaquiline-containing regimen were included. The databases CENTRAL, PubMed and Embase were manually searched, and 866 unique records identified, eventually leading to the inclusion of 13 studies. Phenotypic ABR was assessed based on predefined MIC thresholds and genotypic ABR based on the emergence of resistance-associated variants.ResultsThe median (IQR) frequency of phenotypic ABR was 2.2% (1.1%–4.6%) and 4.4% (1.8%–5.8%) for genotypic ABR. Among the studies reporting individual data of patients with ABR, the median number of likely effective drugs in a treatment regimen was five, in accordance with WHO recommendations. In regard to the utilization of important companion drugs with high and early bactericidal activity, linezolid was included in the regimen of most ABR patients, whereas the usage of other group A (fluoroquinolones) and former group B drugs (second-line injectable drugs) was rare.ConclusionsOur findings suggest a relevant frequency of ABR, urging for a better protection against it. Therefore, treatment regimens should include drugs with high resistance-preventing capacity through high and early bactericidal activity.

Delamanid-containing regimens and multidrug-resistant tuberculosis: A systematic review and meta-analysis

IntroductionMultidrug-resistant tuberculosis (MDR-TB) is a life-threatening condition needing long poly-chemotherapy regimens. As no systematic reviews/meta-analysis is available to comprehensively evaluate the role of delamanid (DLM), we evaluated its effectiveness and safety. MethodsWe reviewed the relevant scientific literature published up to January 20, 2022. The pooled success treatment rate with 95% confidence intervals (CI) was assessed using a random-effect model. We assessed studies for quality and bias, and considered P<0.05 to be statistically significant. ResultsAfter reviewing 626 records, we identified 25 studies that met the inclusion criteria, 22 observational and 3 experimental, with 1276 and 411 patients, respectively. In observational studies the overall pooled treatment success rate of DLM-containing regimens was 80.9% (95% CI 72.6-87.2) with no evidence of publication bias (Begg's test; P >0.05). The overall pooled treatment success rate in DLM and bedaquiline-containing regimens was 75.2% (95% CI 68.1-81.1) with no evidence of publication bias (Begg's test; P >0.05). In experimental studies the pooled treatment success rate of DLM-containing regimens was 72.5 (95% CI 44.2-89.8, P <0.001, I2: 95.1%) with no evidence of publication bias (Begg's test; P >0.05). ConclusionsIn MDR-TB patients receiving DLM, culture conversion and treatment success rates were high despite extensive resistance with limited adverse events.

Interim Outcomes and Adverse Events among Drug-Resistant Tuberculosis Patients Treated with Bedaquiline in the Philippines

Objectives: This study aimed to assess the interim outcomes for drug-resistant tuberculosis (DR-TB) patients treated with bedaquiline regimen under the operational research conditions compared to DR-TB patients treated without bedaquiline in their regimen, and to describe the adverse events that occurred among patients treated with bedaquiline in the Philippines. Design: Patients who were treated with a bedaquiline-containing regimen from June 2016 to May 2017 were included in this study as the intervention group, while patients who were treated without bedaquiline regimen from January 2013 to May 2016 were included as the comparison group. The interim treatment outcomes were compared using Chi-square test. The analysis of time to culture conversion within 6 months of treatment was conducted. A Cox proportional hazard model was constructed to identify the variables associated with a favorable interim treatment outcome. The R program was used for statistical analysis. Results: On the 6th month of treatment, the culture conversion for patients treated with a bedaquiline-containing regimen was significantly higher than with the comparison group [63/75 (84.0%) vs 84/117 (71.8%), p = 0.012)]. Nearly 15% of the patients treated with bedaquiline were lost to follow-up. Frequent adverse events included vomiting, dizziness, nausea, joint pain, and abdominal pain. Conclusion: The patients who were treated with bedaquiline-containing regimen have better interim treatment outcomes than those treated without bedaquiline, but the proportion of patients who were lost to follow-up remains substantial.

The Introduction of Bedaquiline Regimen for Drug-Resistant Tuberculosis in the Philippines: An Operational Study

Objectives: Bedaquiline (BDQ) is the first new anti-tuberculosis (TB) drug introduced to the market after 45 years. Recent studies have shown the potential benefits of adding bedaquiline to regimens for drug-resistant TB (DR-TB). In search of more effective regimens for DR-TB, bedaquiline was introduced in the TB program in the Philippines under operational research to assess its effectiveness, safety, and tolerability when given with background regimens among patients with multi-or extensively DR-TB (MDR/XDR-TB). Design: A prospective cohort study of patients with MDR/XDR-TB was given with a bedaquiline-containing regimen from June 2016 to May 2017. Demographic data, presence of comorbidities, and microbiologic profile on entry were recorded. Bedaquiline was administered at the recommended dose of 400 mg once daily for 14 days, then 200 mg three times a week for 22 weeks together with World Health Organization (WHO)-compliant background regimen. The time to culture conversion, interim outcomes at the 6th month of treatment, end-of-treatment outcomes, and post-treatment follow-up outcomes after one year was determined. The frequency and severity of adverse events (SAE) were recorded as part of pharmacovigilance. Results: Seventy-five patients were given with bedaquiline-containing regimen during the study period. Forty-two (56.0%) had second-line injectable resistance, 23 (30.7%) had fluoroquinolone-resistance, 6 (8.0%) had MDR-TB, and 4 (5.3%) had XDR-TB. In the 6th month of post-enrolment, 79% were culture-negative. The treatment success rate was 65.3% (37 were cured and 12 completed treatment), 7 (9.3%) died, 17 (22.7%) lost to follow-up, and 2 (2.7%) were withdrawn from treatment. Adverse events included vomiting (80%), dizziness (69%), nausea (52%), cough (44%), and headache (36%). The post-treatment follow-up of 49 patients in the 12th month showed 92% were culture-negative while 8% of TBC were not done. Conclusion: Bedaquiline-containing regimens for patients with MDR/XDR-TB were highly effective with an acceptable safety profile and favorable treatment outcomes, but the proportion of patients who lost to follow-up remains substantial.

Pharmacodynamics and Bactericidal Activity of Bedaquiline in Pulmonary Tuberculosis.

Bedaquiline is a diarylquinoline antimycobacterial drug and a key component of several regimens in clinical development for the treatment of tuberculosis (TB) but with ongoing phase 3 trials that include assessment of simplified dosing. A pharmacokinetic-pharmacodynamic model of bedaquiline Mycobacterium tuberculosis-killing kinetics in adults with pulmonary TB was developed to inform dose selection of bedaquiline-containing regimens. The model parameters were estimated with data from the 14-day early bactericidal activity (EBA) study TMC207-CL001 conducted in Cape Town, South Africa. The study included 60 adult males and females with drug-susceptible pulmonary TB, who were administered bedaquiline with loading doses on the first 2 days followed by once-daily 100 mg, 200 mg, 300 mg, or 400 mg. The modeling results included expected values (means ± standard deviations [SDs]) for a maximum drug kill rate constant equal to 0.23 ± 0.03 log10 CFU/mL sputum/day, a half-maximum effective plasma concentration equal to 1.6 ± 0.3 mg/L, and an average time to onset of activity equal to 40 ± 7 h. Model simulations showed that once-daily 200 mg, 300 mg, and 400 mg (without loading doses) attained 40%, 50%, and 60%, respectively, of an expected maximum 14-day EBA equal to 0.18 log10 CFU/mL/day, or 10 h/day assessed by liquid culture time to positivity (TTP). Additional simulations illustrated efficacy outcomes during 8 weeks of treatment with the recommended and alternative dosages. The results demonstrate a general mathematical and statistical approach to the analysis of EBA studies with broad application to TB regimen development.

Emergence of bedaquiline resistance in a high tuberculosis burden country.

RationaleBedaquiline has been classified as a group A drug for the treatment of multidrug-resistant tuberculosis (MDR-TB) by the World Health Organization; however, globally emerging resistance threatens the effectivity of novel MDR-TB treatment regimens.ObjectivesWe analysed pre-existing and emerging bedaquiline resistance in bedaquiline-based MDR-TB therapies, and risk factors associated with treatment failure and death.MethodsIn a cross-sectional cohort study, we employed patient data, whole-genome sequencing (WGS) and phenotyping of Mycobacterium tuberculosis complex (MTBC) isolates. We could retrieve baseline isolates from 30.5% (62 out of 203) of all MDR-TB patients who received bedaquiline between 2016 and 2018 in the Republic of Moldova. This includes 26 patients for whom we could also retrieve a follow-up isolate.Measurements and main resultsAt baseline, all MTBC isolates were susceptible to bedaquiline. Among 26 patients with available baseline and follow-up isolates, four (15.3%) patients harboured strains which acquired bedaquiline resistance under therapy, while one (3.8%) patient was re-infected with a second bedaquiline-resistant strain. Treatment failure and death were associated with cavitary disease (p=0.011), and any additional drug prescribed in the bedaquiline-containing regimen with WGS-predicted resistance at baseline (OR 1.92 per unit increase, 95% CI 1.15–3.21; p=0.012).ConclusionsMDR-TB treatments based on bedaquiline require a functional background regimen to achieve high cure rates and to prevent the evolution of bedaquiline resistance. Novel MDR-TB therapies with bedaquiline require timely and comprehensive drug resistance monitoring.

Genetic variants and their association with phenotypic resistance to bedaquiline in Mycobacterium tuberculosis: a systematic review and individual isolate data analysis

SummaryBackgroundBedaquiline is a crucial drug for control of rifampicin-resistant tuberculosis. Molecular drug resistance assays could facilitate effective use of bedaquiline and surveillance of drug resistance emergence. To facilitate molecular assay development, we aimed to identify genomic markers of bedaquiline resistance.MethodsIn this systematic review and individual isolate analysis, we searched Europe PubMed Central and Scopus for studies published from the inception of each database until Oct 19, 2020, that assessed genotypic and phenotypic bedaquiline resistance in clinical or non-clinical Mycobacterium tuberculosis isolates. All studies reporting on the assessment of variants in the four genes of interest (Rv0678, atpE, pepQ, and Rv1979c) and phenotypic bedaquiline data in both clinical and non-clinical samples were included. We collated individual isolate data from eligible studies to assess the association between genomic variants with phenotypic bedaquiline resistance, using a standardised method endorsed by WHO. Risk of bias of the extracted data was independently assessed by two authors using the Quality Assessment of Diagnostic Accuracy Studies tool for clinical studies and Systematic Review Center for Laboratory Animal Experimentation tool for animal studies. The primary outcome was to identify mutations associated with resistance in four genes of interest (Rv0678, atpE, pepQ, and Rv1979c); for each genomic variant, the odds ratio (OR), 95% CI, and p value were calculated to identify resistance markers associated with bedaquiline resistance. This study is registered with PROSPERO, CRD42020221498.FindingsOf 1367 studies identified, 41 published between 2007 and 2020 were eligible for inclusion. We extracted data on 1708 isolates: 1569 (91·9%) clinical isolates and 139 (8·1%) non-clinical isolates. We identified 237 unique variants in Rv0678, 14 in atpE, 28 in pepQ, and 11 in Rv1979c. Most clinical isolates with a single variant reported in Rv0678 (229 [79%] of 287 variants), atpE (14 [88%] of 16 variants), pepQ (32 [100%] of 32 variants), or Rv1979c (115 [98%] of 119 variants) were phenotypically susceptible to bedaquiline. Except for the atpE 187G→C (OR ∞, [95% CI 13·28–∞]; p<0·0001) and Rv0678 138_139insG (OR 6·91 [95% CI 1·16–47·38]; p=0·016) variants, phenotypic–genotypic associations were not significant (p≥0·05) for any single variant in Rv0678, atpE, pepQ, and Rv1979c.InterpretationAbsence of clear genotypic–phenotypic associations for bedaquiline complicates the development of molecular drug susceptibility tests. A concerted global effort is urgently needed to assess the genotypic and phenotypic drug susceptibility of M tuberculosis isolates, especially in patients who have received unsuccessful bedaquiline-containing regimens. Treatment regimens should be designed to prevent emergence of bedaquiline resistance and phenotypic drug susceptibility tests should be used to guide and monitor treatment.FundingResearch Foundation Flanders, South African Medical Research Council, Department of Science and Innovation - National Research Foundation, National Institute of Health Institute of Allergy and Infectious Diseases, and Doris Duke Charitable Foundation.

Insignificant difference in culture conversion between bedaquiline-containing and bedaquiline-free all-oral short regimens for multidrug-resistant tuberculosis

BackgroundMultidrug-resistant tuberculosis (MDR-TB) patients have been suffering long, ineffective, and toxic treatment until short-course injectable-free regimens emerged. However, the new WHO-recommended regimens might be less feasible in the real-world setting. Here, we evaluated two optimized all-oral short-course regimens in China. MethodsFrom April 2019 to August 2020, we conducted a prospective nonrandomized controlled trial and consecutively included 103 MDR-TB patients diagnosed with pulmonary MDR-TB in Shenzhen, China. A 4-5 drug regimen of 9-12 months was tailored to the strain's resistance patterns, patients' affordability, and tolerance to drugs. This was an interim analysis, focusing on the early treatment period. Results53.4% (55/103) of patients were prescribed linezolid, fluoroquinolone (FQ), clofazimine, cycloserine, and pyrazinamide, followed by a regimen in which clofazimine was replaced by bedaquiline (35/103, 34.0%). The culture conversion rate was 83.1% and 94.4% at two and four months, respectively, with no significant difference between bedaquiline-free and bedaquiline-containing cases and between FQ-susceptible and FQ-resistant cases. Among 41 patients who completed treatment, 40 (97.6%) patients had a favorable outcome and no relapse was observed. Peripheral neuropathy and arthralgia/myalgia were the most frequent AEs (56.3%, 58/103). 18 AEs caused permanent discontinuation of drugs, mostly due to pyrazinamide and linezolid. ConclusionOptimized all-oral short-course regimens showed satisfactory efficacy and safety in early treatment stage. Further research is needed to confirm these results.

Twenty-four-week interim outcomes of bedaquiline-containing regimens in treatment of adolescents with rifampicin-resistant tuberculosis: A retrospective cohort study in China.

To evaluate the 24-week interim outcomes of bedaquiline-containing regimens in the treatment of adolescents with rifampicin-resistant tuberculosis (RR-TB) in China. Adolescents with RR-TB from two hospitals were included in this retrospective study. All patients received the longer regimen containing bedaquiline. Sputum culture, chest computed tomography, blood tests and electrocardiography were performed regularly, and the outcomes after 24 weeks of treatment were reported. Four male and six female adolescents aged 11 to 17 years old were included. Among them, four (40.0%), four (40.0%) and two (20.0%) were confirmed to have RR-TB, multidrug-resistant TB and extensively drug-resistant TB, respectively. The most common companion drugs included linezolid (100.0%), cycloserine (90.0%), pyrazinamide (80.0%), moxifloxacin (50.0%) and levofloxacin (40.0%). Culture conversion rates of 80.0%, 100.0% and 100.0% were observed at weeks 2, 4 and 24, respectively. The mean maximum drug concentration of bedaquiline at weeks 2, 12 and 24 was 3.29 ± 0.66, 1.78 ± 0.81 and 1.93 ± 0.74 μg/mL, respectively. Six adverse events including leukopenia (50.0%), Fridericia-corrected QT (QTcF) interval prolongation (16.7%), anaemia (16.7%) and peripheral neuropathy (16.7%) were observed in five (50.0%) patients. No patient discontinued bedaquiline owing to QTcF interval prolongation. Meanwhile, no deaths, reversions or serious adverse events were reported during 24 weeks of treatment. A longer regimen containing bedaquiline was effective and well tolerated in Chinese adolescents with RR-TB. The combination of bedaquiline and linezolid may be a favourable choice for this population.

Bedaquiline-containing regimens in patients with pulmonary multidrug-resistant tuberculosis in China: focus on the safety

BackgroundWorld Health Organization recommends countries introducing new drug and short treatment regimen for drug resistant tuberculosis (DR-TB) should develop and implement a system for active pharmacovigilance that allows for detection, reporting and management of adverse events. The aim of the study is to evaluate the frequency and severity of adverse events (AEs) of bedaquiline-containing regimen in a cohort of Chinese patients with multidrug-resistant (MDR)/extensively drug-resistant (XDR)-TB based on active drug safety monitoring (aDSM) system of New Drug Introduction and Protection Program (NDIP).MethodsAEs were prospectively collected with demographic, bacteriological, radiological and clinical data from 54 sites throughout China at patient enrollment and during treatment between February, 2018 and December, 2019. This is an interim analysis including patients who are still on treatment and those that have completed treatment. A descriptive analysis was performed on the patients evaluated in the cohort.ResultsBy December 31, 2019, a total of 1162 patients received bedaquiline-containing anti-TB treatment. Overall, 1563 AEs were reported, 66.9% were classified as minor (Grade 1–2) and 33.1% as serious (Grade 3–5). The median duration of bedaquiline treatment was 167.0 [interquartile range (IQR): 75–169] days. 86 (7.4%) patients received 36-week prolonged treatment with bedaquiline. The incidence of AEs and serious AEs was 47.1% and 7.8%, respectively. The most frequently reported AEs were QT prolongation (24.7%) and hepatotoxicity (16.4%). There were 14 (1.2%) AEs leading to death. Out of patients with available corrected QT interval by Fridericia's formula (QTcF) data, 3.1% (32/1044) experienced a post-baseline QTcF ≥ 500 ms, and 15.7% (132/839) had at least one change of QTcF ≥ 60 ms from baseline. 49 (4.2%) patients had QT prolonged AEs leading to bedaquiline withdrawal. One hundred and ninety patients reported 361 AEs with hepatotoxicity ranking the second with high occurrence. Thirty-four patients reported 43 AEs of hepatic injury referred to bedaquiline, much lower than that referred to protionamide, pyrazinamide and para-aminosalicylic acid individually.ConclusionsBedaquiline was generally well-tolerated with few safety concerns in this clinical patient population without any new safety signal identified. The mortality rate was generally low. These data inform significant positive effect to support the WHO recent recommendations for the wide use of bedaquiline.

Interim Effectiveness and Safety Comparison of Bedaquiline-Containing Regimens for Treatment of Diabetic Versus Non-Diabetic MDR/XDR-TB Patients in China: A Multicenter Retrospective Cohort Study.

IntroductionDiabetes mellitus (DM), a common tuberculosis (TB) comorbidity, is associated with delayed bacillary clearance during anti-TB treatment and unfavorable outcomes. Bedaquiline (BDQ), when used as part of multidrug regimen for multidrug-resistant/extensively drug-resistant tuberculosis (MDR/XDR-TB), has been shown to be effective and safe although treatment outcome and risks for patients with MDR/XDR-TB and DM are unknown. A multicenter retrospective study was conducted to compared the safety and effectiveness of 24-week BDQ-containing anti-TB treatment for patients with MDR/XDR-TB with and without DM.MethodsThe study of patients with MDR/XDR-TB with or without DM (enrolled February 2018–September 2019, 21 Chinese hospitals) was supervised by the New Drug Introduction and Protection Program (NDIP). Of 640 patients with MDR/XDR-TB receiving BDQ-containing anti-TB treatments, two propensity score-matched groups (107 DM/107 non-DM) were compared for cumulative culture conversion rate, time to culture conversion, adverse events, and corrected QT interval.ResultsBody mass index was higher in patients with DM than patients without DM (23.29 ± 3.9 vs. 20.5 ± 3.6, P < 0.001); lung cavity prevalence (86.9% vs. 72.9%, P = 0.037) was also higher in patients with DM; the non-DM group had higher hepatitis prevalence (29.0% vs. 15.9%, P = 0.022). No significant intergroup differences were found for sputum culture conversion rate at week 8 (80.0% vs. 81.4%, P = 0.884), at week 24 (95.6% vs. 98.2%, P = 0.629), or for median time to sputum culture conversion [56 days (IQR 28–63) vs. 56 days (IQR 28–84) (P = 0.687)]. Favorable post-24-week treatment outcomes were presented by 90.7% and 93.5% in the DM group and non-DM group, respectively, without significant intergroup differences (P = 0.448). The DM adverse event rate exceeded non-DM rate (77.6% vs. 64.5%, P = 0.035).ConclusionDespite some differences in baseline characteristics, Chinese patients with MDR/XDR-TB with or without DM had similar sputum culture conversion rates and favorable treatment outcomes post-24-week BDQ-containing anti-TB treatment. Low BMI but not DM is risk factor associated with unfavorable outcome of patients with MDR/XDR-TB.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40121-021-00396-9.

Effectiveness and safety of delamanid- or bedaquiline-containing regimens among children and adolescents with multidrug resistant or extensively drug resistant tuberculosis: A nationwide study from Belarus, 2015-19.

There is limited evidence describing the safety and effectiveness of bedaquiline and delamanid containing regimens in children and adolescents with Multidrug-Resistant Tuberculosis (MDR-TB) and Extensively Drug-Resistant Tuberculosis (XDR-TB) globally. In this nationwide descriptive cohort study from Belarus, we examined adverse drug events, time to culture conversion, treatment outcomes including post-treatment recurrence among children and adolescents (<18 years of age) treated with bedaquiline and/or delamanid containing regimens from 2015 to 2019. Of the 40 participants included (55% females; age range 10-17 years), 20 (50%) had XDR-TB and 15 (38%) had resistance to either fluoroquinolone or second-line injectable. Half of the patients received delamanid and another half received bedaquiline with one patient receiving both drugs. AEs were reported in all the patients. A total of 224 AEs were reported, most of which (76%) were mild in nature. Only 10 (5%) AEs were graded severe and one AE was graded life-threatening. A total of 7 AEs (3%) were classified as 'serious' and only one patient required permanent discontinuation of the suspected drug (linezolid). Most of the AEs (94%) were resolved before the end of treatment. All patients culture-positive at baseline (n=34) became culture-negative within three months of treatment. Median time to culture conversion was 1.1 months (interquartile range: 0.9-1.6). Two patients were still receiving treatment at the time of analysis. The remaining 38 patients successfully completed treatment. Among those eligible and assessed at 6 (n=32) and 12 months (n=27) post-treatment, no recurrences were detected. In conclusion, treatment of children and adolescents with MDR-TB and XDR-TB using bedaquiline and/or delamanid containing regimens was effective and had favourable safety profile. Achieving such excellent outcomes under programmatic settings is encouraging for other national tuberculosis programmes, which are in the process of introducing or scaling-up the use of these new drugs in their countries.

Acquisition of Cross-Resistance to Bedaquiline and Clofazimine following Treatment for Tuberculosis in Pakistan

Aims and objectives: In the present study, we report on the first seven cases of acquired bedaquiline and clofazimine resistance identified in Pakistan. The study was conducted within the framework of a retrospective surveillance project to monitor the acquisition of resistance to bedaquiline implemented by the National TB Reference Laboratory in Pakistan and TB Supranational Reference Laboratory. Methods: Seventy three sequential isolates from 31 drug-resistant-tuberculosis patients on bedaquiline-containing regimens were retrospectively tested for bedaquiline resistance by MIC testing in 7H11 medium, and for all isolates showing an increased MIC compared to the baseline isolate, further MIC testing for bedaquiline and clofazimine was conducted using the Bactec MGIT960 (BD, Franklin Lakes, NJ, USA). The H37Rv (ATCC 27294) strain was used as a susceptible control in MIC testing. Bedaquiline dry powder was supplied by Janssen-Pharmaceutica (Beerse, Belgium). WGS was carried out with the Illumina Nextera-XT DNA sample preparation kit to prepare paired-end libraries of 150-bp read length to sequence on an Illumina NextSeq platform. Data analysis and single nucleotide polymorphism (SNP) calling were performed using the MTBseq-Pipeline on low-frequency detection mode. Genes associated with resistance to bedaquiline and/or clofazimine (atpE, Rv0678, pepQ, and Rv1979c) were screened for mutations. Results: We studied 73 isolates from patients (n=31; 8 MDR, 16 pre-XDR, and 7 XDR) enrolled in bedaquiline-containing regimens. The sequential isolates tested included two strains from 22 patients, three from 7 patients, and four from 2 patients. All baseline strains included in the study were sensitive to bedaquiline. Seven patients developed an increase in bedaquiline MICs in 7H11 medium (range, 0.125 to &gt;0.5mg·liter−1) during therapy, and six of them became resistant to bedaquiline according to the current critical concentration proposed for the drug. In all seven patients we detected genetic variants in Rv0678 that were not present at baseline isolates. Moreover in five out of seven patients the treatment was ultimately failed. Conclusions: We documented cases failing therapy that developed specific mutations in Rv0678 and had increased MICs associated with cross-resistance to clofazimine during treatment. This study underlines the relevance of surveillance programs following the introduction of new drugs.

Treatment Outcomes 24 Months after Initiating Short Bedaquiline- or Injectable-Containing Rifampicin-Resistant Tuberculosis Treatment Regimens: A Retrospective Cohort Study in South Africa

Background: We compared outcomes up to 24 months after treatment initiation for rifampicin-resistant tuberculosis (RR-TB) patients in South Africa treated with a short, all-oral bedaquiline-containing regimen (bedaquiline group), or a short, injectable-containing regimen (injectable group). Methods: RR-TB patients eligible for a short regimen starting treatment between 1 January and 31 December 2017 with a bedaquiline-containing or WHO recommended injectable-containing treatment regimen of 9 to 12 months, registered with their national ID in the drug-resistant TB database and with known age, sex, and HIV status were eligible for study inclusion. To compare regimens, we exactly matched patients on HIV-infection, previous TB treatment history, baseline acid-fast bacilli smear and culture result, and propensity score matched patients on age, sex, and isoniazid susceptibility status, using logistic regression with generalized linear mixed models to estimate adjusted odds ratios (aOR) and 95% confidence intervals (95%CI). Results: Overall, 1,387 of the 10,152 RR-TB patients treated during 2017 met inclusion criteria, of whom 688 received the bedaquiline-containing regimen and 699 patients received the injectable-containing regimen. Four patients (0.6%) had treatment failure and/or recurrence, 44 (6.4%) were lost to follow-up, and 162 (23.5%) died in the bedaquiline group, compared to 17 (2.4%), 87 (12.4%), and 199 (28.5%), respectively, in the injectable group. Patients in the bedaquiline group had 1.8 (95%CI 1.4 to 2.4) times higher odds of treatment success at 24 months and 0.6 (0.4 to 0.8) times lower odds of loss to follow-up. This was consistent in stratified analyses on HIV-status, AFB smear positivity, and previous treatment history. The bedaquiline group had lower odds of mortality during treatment (0.5, 95%CI 0.4 to 0.7), but not post treatment (1.1, 95%CI 0.7 to 1.7). Conclusion: Patients in the bedaquiline group experienced significantly higher rates of treatment success at 24 months compared to the injectable group. The analysis supports the use of short bedaquiline-containing regimens in eligible patients. Funding: WHO Global TB Programme. Declaration of Interest: We declare no competing interests. Ethical Approval: This analysis was approved by Human Research Ethics Committee, Medical of University of Witwatersrand (#M150340, March 2015).

High frequency of bedaquiline resistance in programmatically treated drug-resistant TB patients with sustained culture-positivity in Cape Town, South Africa

Aims &amp; objectives: Potentially transformative new tuberculosis (TB) drugs like bedaquiline are undergoing roll-out, however, this is largely in the absence of programmatic drug susceptibility testing (DST). We lack information on how susceptibility changes during treatment in patients on bedaquiline-containing regimens, especially in at risk patients who have complex treatment histories, are in programmatic rather than trial environments, and have a delayed treatment response (defined here as sustained culture-positivity). Methods: Serial isolates from 51 patients with drug resistant (DR-)TB who were culture-positive after ≥4 months of a programmatically administered bedaquiline-containing regimen, were collected. Bedaquiline phenotypic DST in MGIT 960 (1μg/ml), targeted deep sequencing (Rv0678, atpE, pepQ) and whole genome sequencing was done on paired isolates (pre-bedaquiline initiation, post-four-month). Results: 24/51 (47%) patients were phenotypically and genotypically resistant (39% acquired resistance). Excluding one patient with an unknown history, prior clofazimine exposure was associated with bedaquiline-resistance [21/24 (88%) bedaquiline resistant cases had prior clofazimine vs. 12/26 (46%) susceptibles; p=0.002]. Diverse combinations of single nucleotide polymorphisms (SNPs) and indels were in the Rv0678 promoter region and the Rv0678 and atpE genes. Examples of newly described resistance associated variants (RAVs) include Rv0678 -8 T/G and atpE 223 C/T. RAVs were not in defined hotspots and sometimes occurred concurrently with atpE RAVs. Discussion: The rate of bedaquiline resistance acquisition in this population is alarmingly high and associated with prior clofazimine exposure. The diverse RAVs pose challenges to molecular test development. This study highlights the existence of a potentially infectious pool of bedaquiline-resistant patients present under programmatic conditions in a resource-constrained setting and illustrates the danger of starting patients with complex histories on a novel drug without routinely available DST.

Culture Conversion in Patients Treated with Bedaquiline and/or Delamanid. A Prospective Multicountry Study.

Rationale: Bedaquiline and delamanid offer the possibility of more effective and less toxic treatment for multidrug-resistant (MDR) tuberculosis (TB). With this treatment, however, some patients remain at high risk for an unfavorable treatment outcome. The endTB Observational Study is the largest multicountry cohort of patients with rifampin-resistant TB or MDR-TB treated in routine care with delamanid- and/or bedaquiline-containing regimens according to World Health Organization guidance.Objectives: We report the frequency of sputum culture conversion within 6 months of treatment initiation and the risk factors for nonconversion.Methods: We included patients with a positive baseline culture who initiated a first endTB regimen before April 2018. Two consecutive negative cultures collected 15 days or more apart constituted culture conversion. We used generalized mixed models to derive marginal predictions for the probability of culture conversion in key subgroups.Measurements and Main Results: A total of 1,109 patients initiated a multidrug treatment containing bedaquiline (63%), delamanid (27%), or both (10%). Of these, 939 (85%) experienced culture conversion within 6 months. In adjusted analyses, patients with HIV had a lower probability of conversion (0.73; 95% confidence interval [CI], 0.62–0.84) than patients without HIV (0.84; 95% CI, 0.79–0.90; P = 0.03). Patients with both cavitary disease and highly positive sputum smear had a lower probability of conversion (0.68; 95% CI, 0.57–0.79) relative to patients without either (0.89; 95% CI, 0.84–0.95; P = 0.0004). Hepatitis C infection, diabetes mellitus or glucose intolerance, and baseline resistance were not associated with conversion.Conclusions: Frequent sputum conversion in patients with rifampin-resistant TB or MDR-TB who were treated with bedaquiline and/or delamanid underscores the need for urgent expanded access to these drugs. There is a need to optimize treatment for patients with HIV and extensive disease.

New drugs and treatment recommendations - what are the consequences at the TB-laboratory?

Aims &amp; objectives: Resistance to TB drugs is a severe obstacle to effective TB control globally. Timely detection of multidrug-resistant TB (MDR-TB) is crucial to avoid poor cure rates and further development and transmission of increasingly drug-resistant strains of M. tuberculosis. Molecular rapid tests are recommended by WHO for the early detection of mutations associated with drug-resistance. When resistance to rifampicin and/or isoniazid is detected, additional DST should be performed for additional drugs. Optimally all drugs used in the therapy of MDR-TB should be tested, and regimens include only drugs to which the patient's isolate has documented susceptibility. The recent introduction of new anti-TB drugs made more effective and shorter treatment of MDR-TB possible. An example is the WHO recommended all-oral bedaquiline-containing MDR-TB regimen (WHO TB treatment handbook 2020) which contains bedaquiline, levofloxacin/moxifloxacin, clofazimine, ethionamide, ethambutol, isoniazid (high dose) and pyrazinamide for 4 months followed by 5 months of treatment with levofloxacin/moxifloxacin, clofazimine, ethambutol and pyrazinamide. The use of rapid diagnostic tests and more effective MDR-TB treatment regimens has the potential to improve treatment outcomes and reduce transmission of MDR-TB. Results: The introduction of new drugs and WHO recommendations for the therapy of MDR-TB put increased demands on TB-laboratories around the world to update their diagnostics algorithms to make sure they reflect new treatment regimens. If possible, DST should be performed for all drugs used in modern MDR-TB therapy. It is a challenge for TB laboratories to introduce DST for several compounds not earlier tested. On the other hand, DST of obsolete drugs such as the second line injectables, and especially kanamycin and capreomycin which are no longer recommended for use should be discontinued. Standardized protocols with critical concentrations for solid or liquid culture-based assays are needed to enable a successful re-focusing of DST at clinical TB laboratories. The possible added value of MIC determinations, as an alternative to just testing a single critical drug concentration, should be considered especially for the new drugs where we have more limited experience. Irrespectively of the method, there is a strong need for relevant drug-susceptible and drug-resistant control strains to ensure high quality when a new DST method is introduced. It is also of importance to develop and implement QC/EQA methods for all drugs tested. The need for knowledge transfer and training should not be neglected. Conclusions: Extended DST is initially a task of the NRL. In high drug-resistant TB burden areas, there might be a subsequent need for decentralization. To meet the demands of rapid detection of drug resistance there is a need for increased use of molecular tests. Such tests promise to be increasingly useful, but they can not be initiated for new drugs until we have a sufficient understanding of which genetic markers need to be examined to predict clinically relevant drug resistance in a reliable way. Research is ongoing to determine this for the new drugs and I expect to see such tests developed in the not so far future.