Combination Therapy Modeling for M tuberculosis Resistance Suppression and Kill

描述(申请人提供)：结核分枝杆菌(Mtb)每年感染全球20多亿人，导致140万人死亡。由药物敏感的结核分枝杆菌引起的结核病的标准治疗包括2个月的利福平(RIF)、异烟肼(INH)、吡津酰胺(PZA)和乙胺丁醇(EMB)，然后是4个月的RIF和INH。在临床结核病患者中，结核分枝杆菌存在3种代谢状态：对数生长期、半休眠酸性相和非复制持久性(NRP)状态。NRP Mtb需要长期治疗才能杀死，并且是疾病复发的罪魁祸首。RIF、INH和EMB杀死对数相生长的Mtb，而PZA杀死酸性相Mtb。RIF还可以杀死NRP Mtb。因此，标准方案中只有一种药物对酸性相和NRP Mtb有效。耐多药结核杆菌(MDR-TB)的流行正在上升，原因是对结核病使用了经验性抗生素组合，这些结核病是由预先对方案中的一种或多种药物产生耐药性的微生物引起的，即使在直接观察疗法下也是如此，给药错误，以及患者不遵守长疗程的治疗。在对药物敏感的结核分枝杆菌和耐多药结核病的标准方案中加入具有新作用机制的新抗生素的研究中，动物模型的细菌灭菌时间和临床试验中痰菌阴转的时间都缩短了，这表明由标准一线和二线结核病药物组成的方案没有优化来杀死结核分枝杆菌。我们的长期目标是开发改进的结核病治疗方案。最重要的假设是，药效学(PD)优化的结核病方案可以在所有3种代谢状态下杀死结核分枝杆菌，并防止不太敏感的细菌亚群的扩大，这将提供一种有效的较短疗程的结核病方案，将改善治疗结果并减少耐药性。我们将验证这一假设，并通过完成以下特定目标来开发高效的短程方案：特定目标#1.在体外中空纤维感染模型(HFIM)中模拟临床相关剂量的3种在所有代谢状态下都具有活性的新型结核病抗生素的游离肺PK曲线，确定每种药物的P指数、药物暴露和给药间隔，以优化DS-Mtb在三种代谢状态下的杀死速度和程度。确定这些单一药物方案是否可以防止耐药性。具体目的#2。利用HFIM，比较DS-Mtb在3种代谢状态下的杀伤率和杀伤率，以及当在特定目的#1中开发的PD优化方案作为2种和3种药物组合使用时，这些抗生素对较不敏感的结核分枝杆菌人群的影响。使用创新的数学模型来确定3种药物方案中每种抗生素的剂量和给药频率，预计该方案通过优化每种代谢状态下结核杆菌的杀灭和防止耐药性，为人类结核病的治疗提供更短的疗程和高效的方案。具体目标#3.使用HFIM，表征PD优化的3种药物方案对耐药的菌株在3种代谢状态下对结核分枝杆菌的杀伤率和杀灭程度的有效性。 具体目标#4：前瞻性地验证创新的PD优化的药物方案在一种新型的小鼠肺结核模型中的性能，在该模型中，结核分枝杆菌处于对数期、酸性相和NRP状态共存，以及在另一种创新的结核病体内模型中，使用最先进的剂量算法，使动物产生的PK曲线“人性化”。使用新的小鼠模型来表征该方案在杀死DS-TB和MDR-TB方面的相对有效性。

DESCRIPTION (provided by applicant): Mycobacterium tuberculosis (Mtb) infects over 2 billion people worldwide and causes 1.4 million deaths annually. The standard treatment for tuberculosis (TB) due to drug-susceptible Mtb consists of 2 months of rifampin (RIF), isoniazid (INH), pyrazinamide (PZA) and ethambutol (EMB) followed by 4 months of RIF and INH. In patients with clinical TB, Mtb exists in 3 metabolic states: log phase growth, semi-dormant acidic phase, and a non-replicating persister (NRP) state. NRP Mtb requires prolonged therapy to kill and is responsible for disease relapse. RIF, INH and EMB kill log phase growth Mtb, while PZA kills acidic phase Mtb. RIF also kills NRP Mtb. Thus, only one drug in the standard regimen is active against acidic phase and NRP Mtb. The prevalence of multidrug resistant Mtb (MDR-TB) is rising due to the use of empiric antibiotic combinations for TB caused by microbes that are resistant to one or more drugs in the regimen a priori, errors in the administration of the medications even under Direct Observed Therapy, and patient non-compliance with the long treatment course. In studies in which new antibiotics with novel mechanisms of action are added to the standard regimen for drug-susceptible Mtb and MDR-TB the time to bacterial sterilization in animal models and the time for sputum conversion to negative in clinical trials are shortened, showing that regimens consisting of the standard first and second line TB drugs are not optimized to kill Mtb. Our long term objective is to develop improved TB regimens. The overarching hypothesis is that TB regimens that are pharmacodynamically (PD) optimized to kill Mtb in all 3 metabolic states and to prevent amplification of less-susceptible bacterial subpopulations will provide a potent shorter course TB regimen that will improve treatment outcomes and reduce resistance. We will test this hypothesis and develop a highly effective short course regimen by completing the following Specific Aims: Specific Aim #1. Simulating in an in vitro hollow fiber infection model (HFIM) the free pulmonary PK profiles for clinically relevant doses of 3 novel TB antibiotics that have activity in all metabolic states, identify the P-indices, drug exposures, and dosing intervals of each drug that PD-optimizes the rapidity and extent of killing of DS-Mtb in each of the 3 metabolic states. Determine if these single drug regimens can prevent resistance. Specific Aim #2. With the HFIM, compare the rates and extents of killing of DS-Mtb in the 3 metabolic states and the effect of these antibiotics on the less susceptible Mtb population when the PD-optimized regimens developed in Specific Aim #1 are used as 2 and 3 drug combinations. Employ innovative mathematical models to identify the dose and frequency of administration of each antibiotic in a 3 drug regimen that is predicted to provide a shorter course, highly effective regimen for the treatment of human TB by optimizing the killing of Mtb in each metabolic state and by preventing resistance. Specific Aim #3. Using the HFIM, characterize the efficacy of the PD-optimized 3 drug regimen on the rate and extent of killing of Mtb in 3 metabolic states for strains that are resistant to 1 of the drug components. Specific Aim #4. Prospectively validate the performance of the innovative PD-optimized 3 drug regimen in a novel murine model of pulmonary TB in which Mtb in log phase, acidic phase, and NRP state co-exist and in another innovative in vivo model of TB using state-of-the-art dosing algorithms that "humanize" the PK profiles generated in the animals. Use the novel murine model to characterize the relative efficacy of this regimen for the killing of DS- and MDR-TB.