Dataset Information

Comparative Efficacy of the Novel Diarylquinoline TBAJ-587 and Bedaquiline against a Resistant Rv0678 Mutant in a Mouse Model of Tuberculosis.

ABSTRACT: Since its conditional approval in 2012, bedaquiline (BDQ) has been a valuable tool for treatment of drug-resistant tuberculosis. More recently, a novel short-course regimen combining BDQ with pretomanid and linezolid won approval to treat highly drug-resistant tuberculosis. Clinical reports of emerging BDQ resistance have identified mutations in Rv0678 that derepress the expression of the MmpL5/MmpS5 efflux transporter as the most common cause. Because the effect of these mutations on bacterial susceptibility to BDQ is relatively small (e.g., 2 to 8× MIC shift), increasing the BDQ dose would increase antibacterial activity but also pose potential safety concerns, including QTc prolongation. Substitution of BDQ with another diarylquinoline with superior potency and/or safety has the potential to overcome these limitations. TBAJ-587 has greater in vitro potency than BDQ, including against Rv0678 mutants, and may offer a larger safety margin. Using a mouse model of tuberculosis and different doses of BDQ and TBAJ-587, we found that against wild-type M. tuberculosis H37Rv and an isogenic Rv0678 mutant, TBAJ-587 has greater efficacy against both strains than BDQ, whether alone or in combination with pretomanid and either linezolid or moxifloxacin and pyrazinamide. TBAJ-587 also reduced the emergence of resistance to diarylquinolines and pretomanid.

SUBMITTER: Xu J

PROVIDER: S-EPMC8097419 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Mycobacterium tuberculosis develops spontaneous resistance mutants to virtually every drug in use. Courses of therapy select for these mutants and drug-resistant organisms emerge. The development of drug-resistant organisms has reached the point that drug resistance now threatens to undermine global success against tuberculosis (TB). New drugs are needed. The last new class of drugs specifically developed for treatment of TB was the rifamycins over 40 years ago. New funding sources and the development of product development partnerships have energized the TB drug development effort. There are now more TB drugs in development than at any time in the past. The first of these drugs to be developed and marketed was bedaquiline. Bedaquiline has an entirely novel mechanism of action and so should be active against otherwise highly resistant organisms. It acts on the transmembrane component of adenosine triphosphate synthase and acts by preventing electron transport. This raises the exciting possibility that bedaquiline may be active against less metabolically active organisms. Drug-drug interactions between rifamycins and the cytochrome P450-3A system will limit bedaquiline's utility and create complexity in treatment regimens. In clinical trials, treatment with bedaquiline added to a background multidrug-resistant TB regimen was associated with earlier culture conversion and higher cure rates, but there were unexplained excess deaths in the bedaquiline arms of these trials. Food and Drug Administration approved bedaquiline for the treatment of multidrug-resistant TB when an effective treatment regimen cannot otherwise be provided. They required a black box warning about excess deaths and require that a phase III trial be completed. A planned Phase III trial is being reorganized. While bedaquiline is an exciting drug and marks a dramatic moment in the history of TB treatment, its ultimate place in the anti-TB drug armamentarium is unclear pending the Phase III trial and the development of other new drugs that are in the pipeline.

Project description:Bedaquiline (BDQ), which is recommended for the treatment of drug-resistant tuberculosis (DR-TB), was introduced in Taiwan in 2014. Due to the alarming emergence of BDQ resistance, we conducted BDQ resistance analyses to strengthen our DR-TB management program. This retrospective population-based study included initial Mycobacterium tuberculosis isolates from 898 rifampicin-resistant (RR) or multidrug-resistant (MDR) TB cases never exposed to BDQ during 2008–2019. We randomly selected 65 isolates and identified 28 isolates with BDQ MIC<0.25μg/ml and MIC≥0.25μg/ml as the control and study groups, respectively. BDQ drug susceptibility testing (DST) using the MGIT960 system and Sanger sequencing of the atpE, Rv0678, and pepQ genes was conducted. Notably, 18 isolates with BDQ MIC=0.25μg/ml, 38.9% (7/18), and 61.1% (11/18) isolates were MGIT-BDQ resistant and susceptible, respectively. Consequently, we recommended redefining MIC=0.25μg/ml as an intermediate-susceptible category to resolve discordance between different DST methods. Of the 93 isolates, 22 isolates were MGIT-BDQ-resistant and 77.3% (17/22) of MGIT-BDQ-resistant isolates harbored Rv0678 mutations. After excluding 2 MGIT-BDQ-resistant isolates with borderline resistance (GU400growth control-GU100BDQ≤1day), 100% (15/15) harbored Rv0678 gene mutations, including seven novel mutations [g-14a, Ile80Ser (N=2), Phe100Tyr, Ala102Val, Ins g 181–182 frameshift mutation (N=2), Del 11–63 frameshift mutation, and whole gene deletion (N=2)]. Since the other 22.7% (5/22) MGIT-BDQ-resistant isolates with borderline resistance (GU400growth control-GU100BDQ≤1day) had no mutation in three analyzed genes. For isolates with phenotypic MGIT-BDQ borderline resistance, checking for GU differences or conducting genotypic analyses are suggested for ruling out BDQ resistance. In addition, we observed favorable outcomes among patients with BDQ-resistant isolates who received BDQ-containing regimens regardless of Rv0678 mutations. We concluded that based on MIC≥0.25μg/ml, 3.1% (28/898) of drug-resistant TB cases without BDQ exposure showed BDQ resistance, Rv0678 was not a robust marker of BDQ resistance, and its mutations were not associated with treatment outcomes.

Dataset Information

Comparative Efficacy of the Novel Diarylquinoline TBAJ-587 and Bedaquiline against a Resistant Rv0678 Mutant in a Mouse Model of Tuberculosis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure