RESUMEN
BACKGROUND: TBAJ-876 is a next-generation diarylquinoline. In vivo, diarylquinoline metabolites are formed with activity against Mycobacterium tuberculosis. Species-specific differences in parent drug-to-metabolite ratios might impact the translational value of animal model-based predictions. This study investigates the contribution of TBAJ-876 and its major active metabolite, TBAJ-876-M3 (M3), to the total bactericidal activity in a mouse tuberculosis model. METHODS: In vitro activity of TBAJ-876 and M3 was investigated and compared to bedaquiline. Subsequently, a dose-response study was conducted in M. tuberculosis-infected BALB/c mice treated with TBAJ-876 (1.6/6.3/25 mg/kg) or M3 (3.1/12.5/50 mg/kg). Colony-forming units in the lungs and TBAJ-876 and M3 plasma concentrations were determined. M3's contribution to TBAJ-876's bactericidal activity was estimated based on M3-exposure following TBAJ-876 treatment and corresponding M3-activity observed in M3-treated animals. RESULTS: TBAJ-876 and M3 demonstrated profound bactericidal activity. Lungs of mice treated for 4 weeks with 50 mg/kg M3 were culture-negative. Following TBAJ-876 treatment, M3-exposures were 2.2-3.6x higher than for TBAJ-876. TBAJ-876 activity was substantially attributable to M3, given its high exposure and potent activity. CONCLUSION: These findings emphasize the need to consider metabolites and their potentially distinct exposure and activity profiles compared to parent drugs to enhance the translational value of mouse model-driven predictions.
RESUMEN
BACKGROUND: Given the persistently high global burden of tuberculosis, effective and shorter treatment options are needed. We explored the relationship between relapse and treatment length as well as interregimen differences for 2 novel antituberculosis drug regimens using a mouse model of tuberculosis infection and mathematical modeling. METHODS: Mycobacterium tuberculosis-infected mice were treated for up to 13 weeks with bedaquiline and pretomanid combined with moxifloxacin and pyrazinamide (BPaMZ) or linezolid (BPaL). Cure rates were evaluated 12 weeks after treatment completion. The standard regimen of isoniazid, rifampicin, pyrazinamide, and ethambutol (HRZE) was evaluated as a comparator. RESULTS: Six weeks of BPaMZ was sufficient to achieve cure in all mice. In contrast, 13 weeks of BPaL and 24 weeks of HRZE did not achieve 100% cure rates. Based on mathematical model predictions, 95% probability of cure was predicted to occur at 1.6, 4.3, and 7.9 months for BPaMZ, BPaL, and HRZE, respectively. CONCLUSION: This study provides additional evidence for the treatment-shortening capacity of BPaMZ over BPaL and HRZE. To optimally use preclinical data for predicting clinical outcomes, and to overcome the limitations that hamper such extrapolation, we advocate bundling of available published preclinical data into mathematical models.
Asunto(s)
Mycobacterium tuberculosis , Tuberculosis , Antituberculosos/farmacología , Antituberculosos/uso terapéutico , Quimioterapia Combinada , Humanos , Pirazinamida/uso terapéutico , Rifampin/farmacología , Rifampin/uso terapéutico , Tuberculosis/tratamiento farmacológico , Tuberculosis/microbiologíaRESUMEN
Analogues of the anti-tuberculosis drug bedaquiline, bearing a 3,5-dimethoxy-4-pyridyl C-unit, retain high anti-bacterial potency yet exert less inhibition of the hERG potassium channel, in vitro, than the parent compound. Two of these analogues (TBAJ-587 and TBAJ-876) are now in preclinical development. The present study further explores structure-activity relationships across a range of related 3,5-disubstituted-4-pyridyl C-unit bedaquiline analogues of greatly varying lipophilicity (clogP from 8.16 to 1.89). This broader class shows similar properties to the 3,5-dimethoxy-4-pyridyl series, being substantially more potent in vitro and equally active in an in vivo (mouse) model than bedaquiline, while retaining a lower cardiovascular risk profile through greatly attenuated hERG inhibition.
Asunto(s)
Antituberculosos/farmacología , Diarilquinolinas/farmacología , Mycobacterium tuberculosis/efectos de los fármacos , Animales , Antituberculosos/síntesis química , Antituberculosos/química , Diarilquinolinas/síntesis química , Diarilquinolinas/química , Relación Dosis-Respuesta a Droga , Humanos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Mycobacterium tuberculosis/crecimiento & desarrollo , Relación Estructura-ActividadRESUMEN
A series of 5,8-disubstituted tetrahydroisoquinolines were shown to be effective inhibitors of M. tb in culture and modest inhibitors of M. tb ATP synthase. There was a broad general trend of improved potency with higher lipophilicity. Large substituents (e.g., Bn) at the tetrahydroquinoline 5-position were well-tolerated, while N-methylpiperazine was the preferred 8-substituent. Structure-activity relationships for 7-linked side chains showed that the nature of the 7-linking group was important; -CO- and -COCH2- linkers were less effective than -CH2- or -CONH- ones. This suggests that the positioning of a terminal aromatic ring is important for target binding. Selected compounds showed much faster rates of microsomal clearance than did the clinical ATP synthase inhibitor bedaquiline, and modest inhibition of mycobacterial ATP synthase.
Asunto(s)
Antituberculosos/farmacología , Mycobacterium tuberculosis/efectos de los fármacos , Tetrahidroisoquinolinas/farmacología , Antituberculosos/síntesis química , Antituberculosos/química , Relación Dosis-Respuesta a Droga , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Relación Estructura-Actividad , Tetrahidroisoquinolinas/síntesis química , Tetrahidroisoquinolinas/químicaRESUMEN
Bedaquiline is a new drug of the diarylquinoline class that has proven to be clinically effective against drug-resistant tuberculosis, but has a cardiac liability (prolongation of the QT interval) due to its potent inhibition of the cardiac potassium channel protein hERG. Bedaquiline is highly lipophilic and has an extremely long terminal half-life, so has the potential for more-than-desired accumulation in tissues during the relatively long treatment durations required to cure TB. The present work is part of a program that seeks to identify a diarylquinoline that is as potent as bedaquiline against Mycobacterium tuberculosis, with lower lipophilicity, higher clearance, and lower risk for QT prolongation. Previous work led to the identification of compounds with greatly-reduced lipophilicity compounds that retain good anti-tubercular activity in vitro and in mouse models of TB, but has not addressed the hERG blockade. We now present compounds where the C-unit naphthalene is replaced by a 3,5-dialkoxy-4-pyridyl, demonstrate more potent in vitro and in vivo anti-tubercular activity, with greatly attenuated hERG blockade. Two examples of this series are in preclinical development.
Asunto(s)
Antituberculosos/farmacología , Diarilquinolinas/farmacología , Canales de Potasio Éter-A-Go-Go/antagonistas & inhibidores , Mycobacterium tuberculosis/efectos de los fármacos , Bloqueadores de los Canales de Potasio/farmacología , Piridinas/farmacología , Antituberculosos/síntesis química , Antituberculosos/química , Diarilquinolinas/síntesis química , Diarilquinolinas/química , Relación Dosis-Respuesta a Droga , Canales de Potasio Éter-A-Go-Go/metabolismo , Humanos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Bloqueadores de los Canales de Potasio/síntesis química , Bloqueadores de los Canales de Potasio/química , Piridinas/síntesis química , Piridinas/química , Relación Estructura-ActividadRESUMEN
The ATP-synthase inhibitor bedaquiline is effective against drug-resistant tuberculosis but is extremely lipophilic (clogP 7.25) with a very long plasma half-life. Additionally, inhibition of potassium current through the cardiac hERG channel by bedaquiline, is associated with prolongation of the QT interval, necessitating cardiovascular monitoring. Analogues were prepared where the naphthalene C-unit was replaced with substituted pyridines to produce compounds with reduced lipophilicity, anticipating a reduction in half-life. While there was a direct correlation between in vitro inhibitory activity against M. tuberculosis (MIC90) and compound lipophilicity, potency only fell off sharply below a clogP of about 4.0, providing a useful lower bound for analogue design. The bulk of the compounds remained potent inhibitors of the hERG potassium channel, with notable exceptions where IC50 values were at least 5-fold higher than that of bedaquiline. Many of the compounds had desirably higher rates of clearance than bedaquiline, but this was associated with lower plasma exposures in mice, and similar or higher MICs resulted in lower AUC/MIC ratios than bedaquiline for most compounds. The two compounds with lower potency against hERG exhibited similar clearance to bedaquiline and excellent efficacy in vivo, suggesting further exploration of C-ring pyridyls is worthwhile.
Asunto(s)
Antituberculosos/farmacología , Diarilquinolinas/farmacología , Canales de Potasio Éter-A-Go-Go/antagonistas & inhibidores , Mycobacterium tuberculosis/efectos de los fármacos , Bloqueadores de los Canales de Potasio/farmacología , Piridinas/farmacología , Animales , Antituberculosos/síntesis química , Antituberculosos/química , Diarilquinolinas/síntesis química , Diarilquinolinas/química , Relación Dosis-Respuesta a Droga , Canales de Potasio Éter-A-Go-Go/metabolismo , Humanos , Ratones , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Bloqueadores de los Canales de Potasio/síntesis química , Bloqueadores de los Canales de Potasio/química , Piridinas/síntesis química , Piridinas/química , Relación Estructura-ActividadRESUMEN
Replacing the naphthalene C-unit of the anti-tuberculosis drug bedaquiline with a range of bicyclic heterocycles of widely differing lipophilicity gave analogs with a 4.5-fold range in clogP values. The biological results for these compounds indicate on average a lower clogP limit of about 5.0 in this series for retention of potent inhibitory activity (MIC90s) against M.tb in culture. Some of the compounds also showed a significant reduction in inhibition of hERG channel potassium current compared with bedaquiline, but there was no common structural feature that distinguished these.
Asunto(s)
Antituberculosos/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Diarilquinolinas/farmacología , Mycobacterium tuberculosis/efectos de los fármacos , Naftalenos/farmacología , Antituberculosos/síntesis química , Antituberculosos/química , Compuestos Bicíclicos Heterocíclicos con Puentes/síntesis química , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Línea Celular Tumoral , Diarilquinolinas/química , Relación Dosis-Respuesta a Droga , Humanos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Naftalenos/química , Relación Estructura-ActividadRESUMEN
Analogues of bedaquiline where the phenyl B-unit was replaced with monocyclic heterocycles of widely differing lipophilicity (thiophenes, furans, pyridines) were synthesised and evaluated. While there was an expected broad positive correlation between lipophilicity and anti-TB activity, the 4-pyridyl derivatives appeared to have an additional contribution to antibacterial potency. The majority of the compounds were (desirably) more polar and had higher rates of clearance than bedaquiline, and showed acceptable oral bioavailability, but there was only limited (and unpredictable) improvement in their hERG liability.
Asunto(s)
Antituberculosos/síntesis química , Diarilquinolinas/química , Compuestos Heterocíclicos/química , Administración Oral , Animales , Antituberculosos/farmacocinética , Antituberculosos/farmacología , Diarilquinolinas/farmacocinética , Diarilquinolinas/farmacología , Canal de Potasio ERG1/antagonistas & inhibidores , Canal de Potasio ERG1/metabolismo , Semivida , Humanos , Concentración 50 Inhibidora , Pruebas de Sensibilidad Microbiana , Microsomas Hepáticos/metabolismo , Mycobacterium tuberculosis/efectos de los fármacos , Ratas , Relación Estructura-ActividadRESUMEN
Drug resistant tuberculsosis (TB) is global health crisis that demands novel treatment strategies. Bacterial ATP synthase inhibitors such as bedaquiline and next-generation analogues (such as TBAJ-876) have shown promising efficacy in patient populations and preclinical studies, respectively, suggesting that selective targeting of this enzyme presents a validated therapeutic strategy for the treatment of TB. In this work, we report tetrahydronaphthalene amides (THNAs) as a new class of ATP synthase inhibitors that are effective in preventing the growth of Mycobacterium tuberculosis (M.tb) in culture. Design, synthesis and comprehensive structure-activity relationship studies for approximately 80 THNA analogues are described, with a small selection of compounds exhibiting potent (in some cases MIC90 <1 µg/mL) in vitro M.tb growth inhibition taken forward to pharmacokinetic and off-target profiling studies. Ultimately, we show that some of these THNAs possess reduced lipophilic properties, decreased hERG liability, faster mouse/human liver microsomal clearance rates and shorter plasma half-lives compared with bedaquiline, potentially addressing of the main concerns of persistence and phospholipidosis associated with bedaquiline.