Explore the vast range of titles available.

Treatment for tuberculosis, a leading cause of death worldwide, typically involves 6 months of continuous therapy. In this trial, a strategy involving shorter initial treatment was noninferior to standard treatment.

[This corrects the article DOI: 10.1371/journal.pone.0241600.].

Pyrazinamide has been a mainstay in the multidrug regimens used to treat tuberculosis. It is active against the persistent, non-replicating mycobacteria responsible for the protracted therapy required to cure tuberculosis. Pyrazinamide is a pro-drug that is converted into pyrazinoic acid (POA) by pyrazinamidase, however, the exact target of the drug has been difficult to determine. Here we show the enzyme PanD binds POA in its active site in a manner consistent with competitive inhibition. The active site is not directly accessible to the inhibitor, suggesting the protein must undergo a conformational change to bind the inhibitor. This is consistent with the slow binding kinetics we determined for POA. Drug-resistant mutations cluster near loops that lay on top of the active site. These resistant mutants show reduced affinity and residence time of POA consistent with a model where resistance occurs by destabilizing the closed conformation of the active site. The important tuberculosis drug pyrazinamide (PZA) is converted to its active form pyrazinoic acid (POA) in Mycobacterium tuberculosis ( Mtb ). Here the authors identify the pantothenate biosynthesis pathway enzyme aspartate decarboxylase (PanD) as the target of PZA and determine the POA bound Mtb PanD crystal structure.

New drugs, but also shorter, better-tolerated regimens are needed to tackle the high global burden of tuberculosis complicated by drug resistance and retroviral disease. We investigated new multiple-agent combinations over the first 14 days of treatment to assess their suitability for future development. In this prospective, randomised, early bactericidal activity (EBA) study, treatment-naive, drug-susceptible patients with uncomplicated pulmonary tuberculosis were admitted to hospitals in Cape Town, South Africa, between Oct 7, 2010, and Aug 19, 2011. Patients were randomised centrally by computer-generated randomisation sequence to receive bedaquiline, bedaquiline-pyrazinamide, PA-824-pyrazinamide, bedaquiline-PA-824, PA-824-moxifloxacin-pyrazinamide, or unmasked standard antituberculosis treatment as positive control. The primary outcome was the 14-day EBA assessed in a central laboratory from the daily fall in colony forming units (CFU) of M tuberculosis per mL of sputum in daily overnight sputum collections. Bilinear regression curves were fitted for each group separately and groups compared with ANOVA for ranks, followed by pair-wise comparisons adjusted for multiplicity. Clinical staff were partially masked but laboratory personnel were fully masked. This study is registered, NCT01215851. The mean 14-day EBA of PA-824-moxifloxacin-pyrazinamide (n=13; 0·233 [SD 0·128]) was significantly higher than that of bedaquiline (14; 0·061 [0·068]), bedaquiline-pyrazinamide (15; 0·131 [0·102]), bedaquiline-PA-824 (14; 0·114 [0·050]), but not PA-824-pyrazinamide (14; 0·154 [0·040]), and comparable with that of standard treatment (ten; 0·140 [0·094]). Treatments were well tolerated and appeared safe. One patient on PA-824-moxifloxacin-pyrazinamide was withdrawn because of corrected QT interval changes exceeding criteria prespecified in the protocol. PA-824-moxifloxacin-pyrazinamide is potentially suitable for treating drug-sensitive and multidrug-resistant tuberculosis. Multiagent EBA studies can contribute to reducing the time needed to develop new antituberculosis regimens. The Global Alliance for TB Drug Development (TB Alliance).

Background Tuberculosis (TB) lymphadenitis is the most common form of extra-pulmonary TB, and the treatment duration is six months. This non-inferiority based randomized clinical trial in South India evaluated the efficacy and safety of a four-month ofloxacin containing regimen in tuberculosis lymphadenitis (TBL) patients. Methods New, adult, HIV-negative, microbiologically and or histopathologically confirmed superficial lymph node TB patients were randomized to either four-month oflaxacin containing test regimen [ofloxacin (O), isoniazid (H), rifampicin (R), pyrazinamide (Z) -2RHZO daily/ 2RHO thrice-weekly] or a six-month thrice-weekly control regimen (2HRZ, ethambutol/4RH). The treatment was directly observed. Clinical progress was monitored monthly during and up to 12 months post-treatment, and thereafter every three months up to 24 months. The primary outcome was determined by response at the end of treatment and TB recurrence during the 24 months post-treatment. Results Of the 302 patients randomized, 298 (98.7%) were eligible for modified intention-to-treat (ITT) analysis and 294 (97%) for per-protocol (PP) analysis. The TB recurrence-free favourable response in the PP analysis was 94.0% (95% CI: 90.1–97.8) and 94.5% (95% CI: 90.8–98.2) in the test and control regimen respectively, while in the ITT analysis, it was 92.7% and 93.2%. The TB recurrence-free favourable response in the test regimen was non-inferior to the control regimen 0.5% (95% CI: -4.8-5.9) in the PP analysis based on the 6% non-inferiority margin. Treatment was modified for drug toxicity in two patients in the test regimen, while one patient had a paradoxical reaction. Conclusion The 4-month ofloxacin containing regimen was found to be non-inferior and as safe as the 6-month thrice-weekly control regimen.

The rise of pyrazinamide (PZA)‐resistant strains of Mycobacterium tuberculosis (MTB) poses a major challenge to conventional tuberculosis (TB) treatments. PZA, a cornerstone of TB therapy, must be activated by the mycobacterial enzyme pyrazinamidase (PZase) to convert its active form, pyrazinoic acid, which targets the ribosomal protein S1. Resistance, often associated with mutations in the RpsA protein, complicates treatment and highlights a critical gap in the understanding of structural dynamics and mechanisms of resistance, particularly in the context of the G97D mutation. This study utilizes a novel integration of computational techniques, including multiscale biomolecular and molecular dynamics simulations, physicochemical and medicinal chemistry predictions, quantum computations and virtual screening from the ZINC and Chembridge databases, to elucidate the resistance mechanism and identify lead compounds that have the potential to improve treatment outcomes for PZA‐resistant MTB, namely ZINC15913786, ZINC20735155, Chem10269711, Chem10279789 and Chem10295790. These computational methods offer a cost‐effective, rapid alternative to traditional drug trials by bypassing the need for organic subjects while providing highly accurate insight into the binding sites and efficacy of new drug candidates. The need for rapid and appropriate drug development emphasizes the need for robust computational analysis to justify further validation through in vitro and in vivo experiments.

ObjectiveTo assess the pharmacokinetics and safety/tolerability of isoniazid, rifampicin and pyrazinamide in children and adolescents with tuberculous meningitis (TBM).DesignProspective observational pharmacokinetic study with an exploratory pharmacokinetic/pharmacodynamic analysis.SettingHasan Sadikin Hospital, Bandung, Indonesia.PatientsIndividuals aged 0–18 years clinically diagnosed with TBM and receiving first-line anti-tuberculosis drug dosages according to revised WHO-recommended treatment guidelines.InterventionsPlasma and cerebrospinal fluid (CSF) concentrations of isoniazid, rifampicin and pyrazinamide were assessed on days 2 and 10 of treatment.Main outcome measuresPlasma exposures during the daily dosing interval (AUC0–24), peak plasma concentrations (C max) and CSF concentrations.ResultsAmong 20 eligible patients, geometric mean AUC0–24 of isoniazid, rifampicin and pyrazinamide was 18.5, 66.9 and 315.5 hour∙mg/L on day 2; and 14.5, 71.8 and 328.4 hour∙mg/L on day 10, respectively. Large interindividual variabilities were observed in AUC0–24 and C max of all drugs. All patients had suboptimal rifampicin AUC0–24 for TBM treatment indication and very low rifampicin CSF concentrations. Four patients developed grade 2–3 drug-induced liver injury (DILI) within the first 4 weeks of treatment, in whom anti-tuberculosis drugs were temporarily stopped, and no DILI recurred after reintroduction of rifampicin and isoniazid. AUC0–24 of isoniazid, rifampicin and pyrazinamide along with C max of isoniazid and pyrazinamide on day 10 were higher in patients who developed DILI than those without DILI (p<0.05).ConclusionHigher rifampicin doses are strongly warranted in treatment of children and adolescents with TBM. The association between higher plasma concentrations of isoniazid, rifampicin and pyrazinamide and the development of DILI needs confirmatory studies.

Background. Drug-induced hepatotoxicity (DIH) is the most common adverse drug reaction leading to interruption of antituberculosis treatment. Worldwide, different reintroduction regimens have been advocated, but no consensus guidelines are available. Reintroduction of antituberculosis drugs in patients with DIH has never been studied systematically. We aimed to compare the safety of 3 different reintroduction regimens of antituberculosis drugs in patients with antituberculosis DIH. Methods. A total of 175 patients with a diagnosis of antituberculosis DIH were randomized to receive 1 of 3 different predefined reintroduction regimens of antituberculosis drugs and were evaluated prospectively. Patients in arm I were given isoniazid, rifampicin, and pyrazinamide simultaneously at full dosage from day 1. In arm II, drugs were administered in a manner similar to that recommended in the American Thoracic Society guidelines for reintroduction. In arm III, drugs were administered in accordance with British Thoracic Society guidelines. Results. Nineteen patients (10.9%) had recurrence of DIH during follow-up. Eight, 6, and 5 patients had recurrence of hepatitis in arms I, II, and III, respectively (P=.69). Of all the clinical and laboratory parameters, pretreatment serum albumin level was the only statistically significant predictor of future recurrence of DIH on reintroduction of antituberculosis drugs (Pµ.01). Conclusions. The recurrence rate of hepatotoxicity was not significantly different between the 3 groups. According to the findings of the present study, all 3 of the potentially hepatotoxic drugs (isoniazid, rifampicin, and pyrazinamide) can be reintroduced simultaneously at full dosage safely from day 1, especially for patients with bilateral extensive pulmonary tuberculosis, to halt disease transmission or to treat patients with life-threatening tuberculosis. Trial registration. ClinicalTrials.gov identifier number: NCT00405301.

WHO recommends a 2-month optimal duration for new drug regimens for rifampicin-susceptible tuberculosis. We aimed to investigate the efficacy and safety of the 8-week regimens that were assessed as part of the TRUNCATE management strategy of the TRUNCATE-TB trial. TRUNCATE-TB was a multi-arm, multi-stage, open-label, randomised controlled trial in which participants aged 18–65 years with rifampicin-susceptible pulmonary tuberculosis were randomly assigned via a web-based system, using permuted blocks, to 24-week standard treatment (rifampicin, isoniazid, pyrazinamide, and ethambutol) or the TRUNCATE management strategy comprising initial 8-week treatment, then post-treatment monitoring and re-treatment where needed. The four 8-week regimens comprised five drugs, modified from standard treatment: high-dose rifampicin and linezolid, or high-dose rifampicin and clofazimine, or bedaquiline and linezolid, all given with isoniazid, pyrazinamide, and ethambutol; and rifapentine, linezolid, and levofloxacin, given with isoniazid and pyrazinamide. Here, we report the efficacy (proportion with unfavourable outcome; and difference from standard treatment, assessed via Bayesian methods) and safety of the 8-week regimens, assessed in the intention-to-treat population. This prespecified exploratory analysis is distinct from the previously reported 96-week outcome of the strategy in which the regimens were deployed. This trial is registered with ClinicalTrials.gov (NCT03474198). Between March 21, 2018, and March 26, 2020, 675 participants (674 in the intention-to-treat population) were enrolled and randomly assigned to the standard treatment group or one of the four 8-week regimen groups. Two 8-week regimens progressed to full enrolment. An unfavourable outcome (mainly relapse) occurred in seven (4%) of 181 participants on standard treatment; 46 (25%) of 184 on the high-dose rifampicin and linezolid-containing regimen (adjusted difference 21·0%, 95% Bayesian credible interval [BCI] 14·3–28·1); and 26 (14%) of 189 on the bedaquiline and linezolid-containing regimen (adjusted difference 9·3% [4·3–14·9]). Grade 3–4 adverse events occurred in 24 (14%) of 181 participants on standard treatment, 20 (11%) of 184 on the rifampicin-linezolid regimen, and 22 (12%) of 189 on the bedaquiline-linezolid regimen. Efficacy was worse with 8-week regimens, although the difference from standard treatment varied between regimens. Even the best 8-week regimen (bedaquiline-linezolid) should only be used as part of a management strategy involving post-treatment monitoring and re-treatment if necessary. Singapore National Medical Research Council; UK Department of Health and Social Care; UK Foreign, Commonwealth, and Development Office; UK Medical Research Council; Wellcome Trust; and UK Research and Innovation Medical Research Council.

Pyrazinamide is a sterilizing first-line tuberculosis drug. Genetic, metabolomic and biophysical analyses previously demonstrated that pyrazinoic acid, the bioactive form of the prodrug pyrazinamide (PZA), interrupts biosynthesis of coenzyme A in Mycobacterium tuberculosis by binding to aspartate decarboxylase PanD. While most drugs act by inhibiting protein function upon target binding, we find here that pyrazinoic acid is only a weak enzyme inhibitor. We show that binding of pyrazinoic acid to PanD triggers degradation of the protein by the caseinolytic protease ClpC1-ClpP. Thus, the old tuberculosis drug pyrazinamide exerts antibacterial activity by acting as a target degrader, a mechanism of action that has recently emerged as a successful strategy in drug discovery across disease indications. Our findings provide the basis for the rational discovery of next generation PZA. It has been shown that the bioactive component of pyrazinamide, pyrazinoic acid (POA), blocks coenzyme A biosynthesis in M. tuberculosis by binding to the aspartate decarboxylase PanD. Here the authors show that pyrazinamide triggers degradation of PanD by stimulating its degradation by the caseinolytic protease Clp.