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Updated: Feb 12, 2026
Growth of Mycobacterium tuberculosis Biofilms
Published on: February 15, 2012
Identifying optimal combination regimens for therapy of Mycobacterium tuberculosis with an algorithmic approach:
Arnold Louie1, Michael Neely2, Sarah Kim1,3
1Institute for Therapeutic Innovation, University of Florida College of Medicine Orlando, Florida, United States of America.
Background:
Mycobacterium tuberculosis resistance to standard-of-care agents is increasing. It is imperative to identify new combinations that increase the rate and depth of bacterial kill, shorten therapy and also suppress resistance. There has been little prior effort to identify combination regimens that employ new or repurposed drugs in a rational way.
Methods And Findings:
Our group developed a pathway to combine agents to achieve this end. This pathway starts with standard baseline evaluations (e.g., MIC), leverages information from in vitro assessments (hollow fiber infection model), then analyzes 2-agent combinations in a 96 well quantitative culture checkerboard format (Greco URSA model with simulation). Finally, development of a high dimensional mathematical model allowed evaluation of 2- and 3-drug regimens in multiple metabolic states to draw inferences regarding combination therapies. We prospectively evaluated these regimens in animal models. We showed that a prospectively chosen regimen of pretomanid, moxifloxacin plus bedaquiline performed as predicted. In the BALB/c murine model, this regimen produced sterilization in a cohort that was held for 12 weeks after therapy cessation, as it did in the C3HeB/FeJ ("Kramnik") murine model. Finally, this and other regimens were evaluated in a cynomolgus macaque model. The decrement of the 18F-deoxyglucose signal in Positron emission tomography (PET)- computed tomography (CT) evaluations was best with this regimen. Other endpoints such as necropsy score and colony counts in lung and lymph nodes also demonstrated that this regimen behaved as predicted from our pathway/algorithm.
Conclusions:
We conclude that this provides a way forward for the future to identify the most promising regimens to shorten therapy for tuberculosis and suppress emergence of resistance.
Insights
A new pathway combining drugs like pretomanid, moxifloxacin, and bedaquiline effectively treats tuberculosis. This combination therapy suppressed resistance and achieved bacterial sterilization in animal models, offering a promising approach for shorter tuberculosis treatment.
Area of Science:
- Drug discovery and development
- Infectious disease research
- Mathematical modeling in medicine
Background:
- Rising resistance of Mycobacterium tuberculosis to current treatments necessitates novel combination therapies.
- Existing efforts to rationally identify new drug combinations for tuberculosis are limited.
- Developing regimens that enhance bacterial kill, shorten treatment duration, and prevent resistance is crucial.
Purpose of the Study:
- To develop and validate a systematic pathway for identifying effective combination therapies against tuberculosis.
- To evaluate novel drug combinations, including those with new or repurposed agents.
- To assess the potential of these combinations to shorten treatment duration and suppress drug resistance.
Main Methods:
- Utilized a multi-step approach starting with baseline evaluations (e.g., MIC).
- Incorporated in vitro assessments using hollow fiber infection models.
- Employed quantitative culture checkerboard assays and mathematical modeling for regimen simulation.
- Prospectively validated promising regimens in BALB/c and C3HeB/FeJ murine models, and cynomolgus macaque models using PET-CT imaging.
Main Results:
- A combination regimen of pretomanid, moxifloxacin, and bedaquiline performed as predicted by the developed pathway.
- This regimen achieved bacterial sterilization in murine models, sustained post-therapy.
- Positron emission tomography (PET)-computed tomography (CT) evaluations in macaques showed the best signal decrement with this regimen, supported by necropsy and colony count data.
Conclusions:
- The developed pathway offers a viable strategy for identifying optimal combination regimens for tuberculosis treatment.
- This approach can lead to shorter therapy durations and effective suppression of drug resistance.
- The findings support the clinical potential of rationally designed drug combinations for combating tuberculosis.
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