Shortened tuberculosis treatment regimens: what is new?
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ABSTRACT:
SUBMITTER: Silva DR
PROVIDER: S-EPMC7462706 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The current treatment regimen against drug susceptible tuberculosis (DS-TB) was defined by the 1980s. Since then the emergence of the global HIV pandemic and the escalation of drug resistant (DR-) forms of TB have presented new challenges for therapeutic research. Priority goals include shortening DS-TB treatment, improving DR-TB treatment and making combined TB-HIV therapy easier. To help achieve these goals, a range of new drugs and treatment strategies are currently being evaluated. Phase IIb and III clinical trials are ongoing to assess combinations involving the high-dose rifamycins, the 8-methoxyquinolones, a diarylquinoline (bedaquiline) and the nitroimidazoles. Other compounds (e.g. novel oxazolidinones and ethylenediamines) are at earlier stages of clinical development. Overall, there are grounds for optimism that recent advances will contribute towards achievement of new treatment regimens in the foreseeable future. However, long-term investment, political commitment and scientific endeavour are crucial to ensure that progress is sustained and the benefits of recent advances reach those in the greatest need.
| S-EPMC3968807 | biostudies-literature
Project description:The emergence of drug-resistant tuberculosis (TB) is a growing problem worldwide. The lack of safe and effective drugs, together with the frequent development of adverse drug reactions can result in worse outcomes. Therefore, new TB drugs able to bolster the current TB treatment regimen are urgently required. Novel drugs that are effective and safe against Mycobacterium tuberculosis are required to reduce the number of drugs and the duration of treatment in both drug-susceptible TB and multi-drug-resistant (MDR)-TB. This review covers promising novel TB drugs and regimens that are currently under development. Bedaquiline and delamanid are the most promising novel drugs for the treatment of MDR-TB, each having a high efficacy and tolerability. However, the best regimen for achieving better outcomes and reducing adverse drug reactions remains yet to be determined, with safety concerns regarding cardiac events due to QT prolongation still to be addressed. Pretomanid is a novel drug that potentially shortens the duration of treatment in both drug-susceptible and drug-resistant TB. Many regimens consisting of injection free drugs with shorter treatment duration compared to the conventional treatment are now undergoing clinical trials. Therefore a simple and short treatment with higher efficacy, and lesser adverse drug reactions and drug-drug interaction is expected for patients with MDR-TB.
| S-EPMC5457944 | biostudies-literature
Project description:Over 480?000 cases of multidrug-resistant (MDR) tuberculosis (TB) occur every year globally, 9% of them being affected by extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis. The treatment of MDR/XDR-TB is unfortunately long, toxic and expensive, and the success rate largely unsatisfactory (<20% among cases with resistance patterns beyond XDR). The aim of this review is to summarise the available evidence-based updated international recommendations to manage MDR/XDR-TB, and to update the reader on the role of newly developed drugs (delamanid, bedaquiline and pretomanid) as well as repurposed drugs (linezolid and meropenem clavulanate, among others) used to treat these conditions within new regimens. A nonsystematic review based on historical trials results as well as on recent literature and World Health Organization (WHO) guidelines has been performed, with special focus on the approach to managing MDR/XDR-TB. The new, innovative global public health interventions, recently approved by WHO and known as the "End TB Strategy", support the vision of a TB-free world with zero death, disease and suffering due to TB. Adequate, universally accessed treatment is a pre-requisite to reach TB elimination. New shorter, cheap, safe and effective anti-TB regimens are necessary to boost TB elimination.
| S-EPMC5005131 | biostudies-literature
Project description:BACKGROUND:Pyrazinamide still may be a useful drug for treatment of rifampin-resistant (RR-TB) or multidrug-resistant tuberculosis (MDR-TB) in China while awaiting scale up of new drugs and regimens including bedaquiline and linezolid. The level of pyrazinamide resistance among MDR-TB patients in China is not well established. Therefore, we assessed pyrazinamide resistance in a representative sample and explored determinants and patterns of pncA mutations. METHODS:MDR-TB isolates from the 2007 national drug resistance survey of China were sub-cultured and examined for pyrazinamide susceptibility by BACTEC MGIT 960 method. pncA mutations were identified by sequencing. Characteristics associated with pyrazinamide resistance were analyzed using univariable and multivariable log-binominal regression. RESULTS:Of 401 MDR-TB isolates, 324 were successfully sub-cultured and underwent drug susceptibility testing. Pyrazinamide resistance was prevalent in 40.7% of samples, similarly among new and previously treated MDR-TB patients. Pyrazinamide resistance in MDR-TB patients was associated with lower age (adjusted OR 0.54; 95% CI, 0.34-0.87 for those aged ≧60 years compared to < 40 years). Pyrazinamide resistance was not associated with gender, residential area, previous treatment history and Beijing genotype. Of 132 patients with pyrazinamide resistant MDR-TB, 97 (73.5%) had a mutation in the pncA gene; with 61 different point mutations causing amino acid change, and 11 frameshifts in the pncA gene. The mutations were scattered throughout the whole pncA gene and no hot spot region was identified. CONCLUSIONS:Pyrazinamide resistance among MDR-TB patients in China is common, although less so in elderly patients. Therefore, pyrazinamide should only be used for treatment of RR/MDR-TB in China if susceptibility is confirmed. Molecular testing for detection of pyrazinamide resistance only based on pncA mutations has certain value for the rapid detection of pyrazinamide resistance in MDR-TB strains but other gene mutations conferring to pyrazinamide resistance still need to be explored to increase its predictive ability .
| S-EPMC6947908 | biostudies-literature
Project description:In the past 2 years, remarkable advances have been made in shortening tuberculosis (TB) treatment. In particular, four clinical trials (Study 31/A5349, Nix-TB, ZeNix and TB-PRACTECAL) have provided evidence of the efficacy of regimens based on new and repurposed drugs: the 4-month regimen for drug-susceptible TB, and the 6-month bedaquiline-pretomanid-linezolid regimen with or without moxifloxacin for multidrug-resistant/rifampicin-resistant TB. Even if the evidence at the basis of these new regimens is compelling, several questions remain open, particularly concerning linezolid dose finding, the upsurging threat of bedaquiline-resistant Mycobacterium tuberculosis and the feasibility of applying these results to the paediatric population. Several ongoing trials may fill the remaining gaps and produce further reliable evidence to address the outstanding questions in TB treatment shortening.
| S-EPMC10567072 | biostudies-literature
Project description:Treatment of latent tuberculosis in patients infected with the human immunodeficiency virus (HIV) is efficacious, but few patients around the world receive such treatment. We evaluated three new regimens for latent tuberculosis that may be more potent and durable than standard isoniazid treatment.We randomly assigned South African adults with HIV infection and a positive tuberculin skin test who were not taking antiretroviral therapy to receive rifapentine (900 mg) plus isoniazid (900 mg) weekly for 12 weeks, rifampin (600 mg) plus isoniazid (900 mg) twice weekly for 12 weeks, isoniazid (300 mg) daily for up to 6 years (continuous isoniazid), or isoniazid (300 mg) daily for 6 months (control group). The primary end point was tuberculosis-free survival.The 1148 patients had a median age of 30 years and a median CD4 cell count of 484 per cubic millimeter. Incidence rates of active tuberculosis or death were 3.1 per 100 person-years in the rifapentine-isoniazid group, 2.9 per 100 person-years in the rifampin-isoniazid group, and 2.7 per 100 person-years in the continuous-isoniazid group, as compared with 3.6 per 100 person-years in the control group (P>0.05 for all comparisons). Serious adverse reactions were more common in the continuous-isoniazid group (18.4 per 100 person-years) than in the other treatment groups (8.7 to 15.4 per 100 person-years). Two of 58 isolates of Mycobacterium tuberculosis (3.4%) were found to have multidrug resistance.On the basis of the expected rates of tuberculosis in this population of HIV-infected adults, all secondary prophylactic regimens were effective. Neither a 3-month course of intermittent rifapentine or rifampin with isoniazid nor continuous isoniazid was superior to 6 months of isoniazid. (Funded by the National Institute of Allergy and Infectious Diseases and others; ClinicalTrials.gov number, NCT00057122.).
| S-EPMC3407678 | biostudies-literature
Project description:One barrier to successful treatment of malignant glioma is resistance to alkylating agents such as temozolomide. The cytotoxic activity of temozolomide and other alkylating agents is believed to manifest largely by the formation of O(6)-methylguanine DNA adducts. Consequently, the primary mechanism of resistance to temozolomide is a function of the activity of the DNA repair enzyme O(6)-methylguanine DNA methyltransferase (MGMT). Fortuitously, MGMT is inactivated after each reaction (i.e., suicide enzyme). Therefore, if the rate of DNA alkylation were to outpace the rate of MGMT protein synthesis, the enzyme could, in theory, be depleted. Several studies have shown that prolonged exposure to temozolomide can deplete MGMT activity in blood cells, a process that could potentially increase the antitumor activity of the drug. To date, however, there are limited data demonstrating the depletion of MGMT activity in tumor tissue exposed to temozolomide. A variety of dosing schedules that increase the duration of exposure and the cumulative dose of temozolomide are currently being investigated for the treatment of glioma, with the goal of improving antitumor activity and overcoming resistance. These alternative dosing regimens have been shown to deplete MGMT activity in peripheral blood mononuclear cells, but the regimen that provides the best balance between enhanced antitumor activity and acceptable hematologic toxicity has yet to be determined.
| S-EPMC2718961 | biostudies-other
Project description:Tools for effective TB control have been available for years. Case finding, active medications, case management and directly observed therapy are the foundations for the management of TB. The current TB epidemic, centered in resource-limited settings is fueled by the HIV-1 epidemic. Lack of ability to diagnose and treat drug-resistant TB has led to development of more extensive patterns of resistance. Among the currently available drugs, there is reason to hope that rifamycins paired with fluoroquinolones will lead to shorter treatment regimens for drug-susceptible TB. As the result of novel public-private collaborations and investments of resources, new drugs are being developed. These include TMC207, already shown to have activity early in the treatment of multidrug-resistant TB and others that are likely to be active against persistor organisms, and have the prospect to dramatically shorten treatment courses for active and latent TB. Given that these drugs have novel mechanisms of action, combinations have the prospect to be highly active even against multidrug-resistant organisms.
| S-EPMC3647464 | biostudies-literature
Project description:Resistance to isoniazid (INH) is the most common form of drug resistance in pulmonary tuberculosis (TB). Although fluoroquinolones (FQs) are recommended to strengthen treatment regimens for INH-resistant pulmonary TB, few studies have evaluated the clinical efficacy of FQ-containing regimens in patients with INH-resistant pulmonary TB. A retrospective cohort study of 140 patients with INH-resistant pulmonary TB was performed between 2005 and 2012. We evaluated whether FQ-containing regimens yielded improved treatment outcomes for patients with INH-resistant pulmonary TB. Overall, favorable outcomes were achieved in 128 (91.4%) patients. Unfavorable outcomes occurred in 12 patients (8.6%), including 7 with treatment failure (5.0%) and 5 with relapse after initial treatment completion (3.6%). FQs, such as levofloxacin and moxifloxacin, were given to 75 (53.6%) patients. Favorable treatment outcomes were more frequent for patients who received FQs (97.3% [73/75 patients]) than for those who did not receive FQs (84.6% [55/65 patients]) (P = 0.007). Patients who did not receive FQs were more likely to develop treatment failure (9.2% [6/65 patients] versus 1.3% [1/75 patients]) (P = 0.049) than patients who received FQs. The adjusted proportion of unfavorable outcomes was significantly higher among patients who did not receive FQs (8.8%; 95% confidence interval [CI], 3.3 to 21.5%) than among those who did receive FQs (1.5%; 95% CI, 0.3 to 7.7%) (P = 0.037). These results suggest that the addition of FQs can improve treatment outcomes for patients with INH-resistant pulmonary TB.
| S-EPMC4704191 | biostudies-literature
Project description:BackgroundComprehensive and reliable drug susceptibility testing (DST) is urgently needed to provide adequate treatment regimens for patients with multidrug-resistant/rifampicin-resistant tuberculosis (MDR/RR-TB). We determined whether next-generation sequencing (NGS) analysis of Mycobacterium tuberculosis complex isolates and genes implicated in drug resistance can guide the design of effective MDR/RR-TB treatment regimens.MethodsNGS-based genomic DST predictions of M. tuberculosis complex isolates from MDR/RR-TB patients admitted to a TB reference center in Germany between 1 January 2015 and 30 April 2019 were compared with phenotypic DST results of mycobacteria growth indicator tubes (MGIT). Standardized treatment algorithms were applied to design individualized therapies based on either genomic or phenotypic DST results, and discrepancies were further evaluated by determination of minimal inhibitory drug concentrations (MICs) using Sensititre MYCOTBI and UKMYC microtiter plates.ResultsIn 70 patients with MDR/RR-TB, agreement among 1048 pairwise comparisons of genomic and phenotypic DST was 86.3%; 76 (7.2%) results were discordant, and 68 (6.5%) could not be evaluated due to the presence of polymorphisms with yet unknown implications for drug resistance. Importantly, 549 of 561 (97.9%) predictions of drug susceptibility were phenotypically confirmed in MGIT, and 27 of 64 (42.2%) false-positive results were linked to previously described mutations mediating a low or moderate MIC increase. Virtually all drugs (99.0%) used in combination therapies that were inferred from genomic DST were confirmed to be susceptible by phenotypic DST.ConclusionsNGS-based genomic DST can reliably guide the design of effective MDR/RR-TB treatment regimens.
| S-EPMC8492214 | biostudies-literature