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Nagar S, Nicholls D, Dawoud D. A systematic review of economic evaluations of pharmacological treatments for active tuberculosis. Front Public Health 2024; 12:1201512. [PMID: 38689771 PMCID: PMC11060080 DOI: 10.3389/fpubh.2024.1201512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 03/04/2024] [Indexed: 05/02/2024] Open
Abstract
Objectives The continuing spread of tuberculosis (TB) worldwide, especially drug-resistant TB, poses a major challenge to healthcare systems globally. Addressing this requires appraising the cost effectiveness of existing pharmacological interventions against TB to identify key drivers of cost effectiveness and value and guide pharmaceutical innovation and novel drug regimen development. Methods Studies were identified from a search of six database: MEDLINE MEDLINE-In Process, MEDLINE Epub Ahead of Print, EMBASE, Cochrane Database of Systematic Reviews, and Econlit in July 2022. Two reviewers independently assessed all identified studies and reports using pre-defined inclusion/exclusion criteria. Study methodological quality was assessed, data were extracted in standard tables, and results were narratively synthesized. Results Overall, 991 studies and 53 HTA reports were identified with 20 studies and 3 HTA reports meeting the inclusion criteria. Quality assessment of the 20 studies identified 4 with minor limitations, while the remainder were assessed as having potentially or very serious limitations. Sixteen studies conducted cost-utility analyses, 6 conducted cost-effectiveness analyses, and 2 conducted cost-comparison analyses with some studies performing multiple analyses. The majority (n = 16) were model-based. Eleven studies analyzed the cost-effectiveness of bedaquiline, 6 compared shorter to longer/standard duration regimens, 2 assessed ethambutol, and 1 assessed delamanid. Key drivers of cost effectiveness were drug costs, the number of TB cases, the portion of cases with sputum culture conversion, treatment delivery costs, and treatment efficacy. Common value elements considered included adverse events, drug resistance, and improving treatment adherence. Conclusion Our results suggest that out of the pharmacological treatments assessed, bedaquiline is likely a cost-effective addition to existing treatment regimens/background treatment regimens, while ethambutol is not likely to be. Newer shorter regimens, even if more costly, seem to be more cost-effective compared to longer regimens. These results illustrate the limited number of novel cost-effective pharmacological interventions and highlight a need to develop new drugs/regimens against TB to overcome resistance, taking into account the key drivers of cost effectiveness and other value attributes identified from this review.
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Affiliation(s)
- Sarosh Nagar
- National Institute for Health and Care Excellence (NICE), London, United Kingdom
- Department of Chemistry & Department of Economics, Harvard College, Harvard University, Boston, MA, United States
| | - David Nicholls
- National Institute for Health and Care Excellence (NICE), London, United Kingdom
| | - Dalia Dawoud
- National Institute for Health and Care Excellence (NICE), London, United Kingdom
- Faculty of Pharmacy, Cairo University, Cairo, Egypt
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Saha P, Das S, Indurthi HK, Kumar R, Roy A, Kalia NP, Sharma DK. Cytochrome bd oxidase: an emerging anti-tubercular drug target. RSC Med Chem 2024; 15:769-787. [PMID: 38516593 PMCID: PMC10953478 DOI: 10.1039/d3md00587a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 01/25/2024] [Indexed: 03/23/2024] Open
Abstract
Cytochrome bd (cyt-bd) oxidase, one of the two terminal oxidases in the Mycobacterium tuberculosis (Mtb) oxidative phosphorylation pathway, plays an indispensable role in maintaining the functionality of the metabolic pathway under stressful conditions. However, the absence of this oxidase in eukaryotic cells allows researchers to select it as a potential drug target for the synthesis of anti-tubercular (anti-TB) molecules. Cyt-bd inhibitors have often been combined with cytochrome bcc/aa3 super-complex inhibitors in anti-TB drug regimens to achieve a desired bactericidal response. The functional redundancy between both the terminal oxidases is responsible for this. The cryo-EM structure of cyt-bd oxidase from Mtb (PDB ID: 7NKZ) further accelerated the research to identify its inhibitor. Herein, we have summarized the reported anti-TB cyt-bd inhibitors, insight into the rationale behind targeting cyt-bd oxidase, and an outline of the architecture of Mtb cyt-bd oxidase.
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Affiliation(s)
- Pallavi Saha
- Department of Pharmaceutical Engg. and Tech, IIT-Banaras Hindu University Varanasi UP 221005 India
| | - Samarpita Das
- Department of Pharmaceutical Engg. and Tech, IIT-Banaras Hindu University Varanasi UP 221005 India
| | - Harish K Indurthi
- Department of Pharmaceutical Engg. and Tech, IIT-Banaras Hindu University Varanasi UP 221005 India
| | - Rohit Kumar
- Department of Pharmaceutical Engg. and Tech, IIT-Banaras Hindu University Varanasi UP 221005 India
| | - Arnab Roy
- Department of Pharmacology and Toxicology, NIPER-Hyderabad Hyderabad 500037 India
| | - Nitin Pal Kalia
- Department of Pharmacology and Toxicology, NIPER-Hyderabad Hyderabad 500037 India
| | - Deepak K Sharma
- Department of Pharmaceutical Engg. and Tech, IIT-Banaras Hindu University Varanasi UP 221005 India
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3
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Byun JY, Kim HL, Lee EK, Kwon SH. A Systematic Review of Economic Evaluations of Active Tuberculosis Treatments. Front Pharmacol 2021; 12:736986. [PMID: 34966276 PMCID: PMC8710595 DOI: 10.3389/fphar.2021.736986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 11/12/2021] [Indexed: 11/16/2022] Open
Abstract
Background: The disease burden of active tuberculosis (TB) is considerable, but systematic reviews of economic evaluations of active TB treatments are scarce. Methods: PubMed, EMBASE, and the Cochrane Library databases were used to search for articles on cost-effectiveness analysis or cost-utility analysis that economically evaluated active TB treatments, which were then systematically reviewed by two independent reviewers. We extracted vital components of the included studies, such as country, population, intervention/comparator, primary outcome, values of outcomes, thresholds, model type, time horizon, and health states included in the model. Results: Seventeen studies were included in this systematic review. Thirteen dealt with interventions of medications, and the remaining four compared care strategies. The Markov model was the most commonly used tool to compare medications, whereas studies on care plans mainly used decision trees. The most commonly used primary outcome was disability-adjusted life years, followed by quality-adjusted life years. For treatment-naïve TB, the 4-month regimen was more cost-effective than the 6-month regimen mainly in low- and middle-income countries. For multidrug-resistant TB, a bedaquiline-based regimen was cost-effective. For multidrug-resistant TB, decentralized care that employed the use of home or mobile devices was more cost-effective than hospital-based centralized care in low- and middle-income countries. Conclusion: New treatment strategies to improve therapeutic outcomes by enhancing treatment adherence, such as regimens with shorter durations (2 or 4 months) and decentralized care, or new anti-TB agents (e.g., bedaquiline) have been suggested as cost-effective interventions for active TB. This review provides information on the economic evaluation of active TB from good-quality studies, thus aiding the future economic evaluation of active TB.
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Affiliation(s)
- Joo-Young Byun
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
| | - Hye-Lin Kim
- College of Pharmacy, Sahmyook University, Seoul, South Korea
| | - Eui-Kyung Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
| | - Sun-Hong Kwon
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
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4
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Padmasawitri TIA, Saragih SM, Frederix GW, Klungel O, Hövels AM. Managing Uncertainties Due to Limited Evidence in Economic Evaluations of Novel Anti-Tuberculosis Regimens: A Systematic Review. PHARMACOECONOMICS - OPEN 2020; 4:223-233. [PMID: 31297751 PMCID: PMC7248140 DOI: 10.1007/s41669-019-0162-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
BACKGROUND Limited evidence for the implementation of new health technologies in low- and middle-income countries (LMICs) may lead to uncertainties in economic evaluations and cause the evaluations to produce inaccurate information for decision making. We performed a systematic review of economic evaluations on implementing new short-course regimens (SCR) for drug-sensitive and drug-resistant tuberculosis (TB), to explore how uncertainties due to the limited evidence in the studies were dealt with and to identify useful information for decision making from these studies. METHODS We searched in electronic databases PubMed, EMBASE, NHSEED, and CEA registry for economic evaluations addressing the implementation of new anti-TB SCRs in LMICs published until September 2018. We included studies addressing both the cost and outcomes of implementing a new regimen for drug-sensitive and drug-resistant TB with a shorter treatment duration than the currently used regimens. The quality of the included studies was assessed using The Consensus Health Economic Criteria checklist. We extracted information from the included studies on uncertainties and how they were managed. The management of uncertainties was compared with approaches used in early health technology assessments (HTAs), including sensitivity analyses and pragmatic scenario analyses. We extracted information that could be useful for decision making such as cost-effectiveness conclusions, and barriers to implementing the intervention. RESULTS Four of the 322 studies found in the search met the eligibility criteria. Three studies were model-based studies that investigated the cost effectiveness of a new first-line SCR. One study was an empirical study investigating the cost effectiveness of new regimens for drug-resistant TB. The model-based studies addressed uncertainties due to limited evidence through various sensitivity analyses as in early HTAs. They performed a deterministic sensitivity analysis and found the main drivers of the cost-effectiveness outcomes, that is, the rate of treatment default and treatment delivery costs. Additionally, two of the model-based studies performed a pragmatic scenario analysis and found a potential barrier to implementing the new first-line SCR, that is, a weak health system with a low TB care utilization rate. The empirical study only performed a few scenario analyses with different regimen prices and volumes of TB care utilization. Therefore, the study could only provide information on the main cost drivers. CONCLUSION Using an approach similar to that used in early HTAs, where uncertainties due to the limited evidence are rigorously explored upfront, the economic evaluations could inform not only the decision to implement the intervention but also how to manage risks and implementation barriers.
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Affiliation(s)
- T I Armina Padmasawitri
- Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht Institute of Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
- Pharmacology and Clinical Pharmacy Research Group, School of Pharmacy, Institut Teknologi Bandung, Bandung, Indonesia
| | - Sarah Maria Saragih
- Department of Health Policy and Health Economics, Faculty of Social Sciences, Eötvös Loránd University (ELTE), Budapest, Hungary
- Department of Public Health, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Gerardus W Frederix
- Julius Centre for Health Sciences and Primary Care, University Medical Centre, Utrecht, The Netherlands
| | - Olaf Klungel
- Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht Institute of Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.
| | - Anke M Hövels
- Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht Institute of Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
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Lin YJ, Lin HC, Yang YF, Chen CY, Lu TH, Liao CM. Shorter antibiotic regimens impact the control efforts in high tuberculosis burden regions of Taiwan. Int J Infect Dis 2020; 97:135-142. [PMID: 32474203 DOI: 10.1016/j.ijid.2020.05.082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 05/17/2020] [Accepted: 05/22/2020] [Indexed: 10/24/2022] Open
Abstract
OBJECTIVES To assess the potential epidemiological impact and cost-effectiveness of shorter antibiotic regimens in high tuberculosis (TB) burden regions of Taiwan. METHODS This study combined the TB population dynamic model and cost-effectiveness analysis with local data to simulate the disease burdens, effectiveness and costs of hypothetical 4-month, 2-month and 7-day regimens compared with the standard regimen. RESULTS The main outcomes were the potential of shorter regimens for averted incidence, mortality and disability-adjusted life years, incremental cost-effectiveness ratio and net monetary benefit. Shorter regimens would lower incidence rates and mortality cases in a high TB burden region by an average of 19-33% and 27-41%, respectively, with the potential for cost-effectiveness or cost-saving. The 2-month and 7-day regimens would be more cost-effective than the 4-month regimen. The threshold daily drug prices for achieving cost-effectiveness and cost-saving for 4-month, 2-month and 7-day regimens were $US1, $US2 and $US70, respectively. Such cost-effectiveness would remain, even if the willingness-to-pay threshold was less than one gross domestic product per capita. CONCLUSIONS The findings support the inclusion of shorter regimens in global guidelines and regional-scale TB control strategies, which would improve disease control, particularly in settings with high rates of incidence and poor treatment outcomes.
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Affiliation(s)
- Yi-Jun Lin
- Institute of Food Safety and Health Risk Assessment, National Yang-Ming University, Taipei, Taiwan
| | - Hsing-Chieh Lin
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan
| | - Ying-Fei Yang
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan
| | - Chi-Yun Chen
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan
| | - Tien-Hsuan Lu
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan
| | - Chung-Min Liao
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan.
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Saini V, Ammerman NC, Chang YS, Tasneen R, Chaisson RE, Jain S, Nuermberger E, Grosset JH. Treatment-Shortening Effect of a Novel Regimen Combining Clofazimine and High-Dose Rifapentine in Pathologically Distinct Mouse Models of Tuberculosis. Antimicrob Agents Chemother 2019; 63:e00388-19. [PMID: 30936097 PMCID: PMC6535519 DOI: 10.1128/aac.00388-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 03/22/2019] [Indexed: 01/09/2023] Open
Abstract
Clofazimine and high-dose rifapentine have each separately been associated with treatment-shortening activity when incorporated into tuberculosis (TB) treatment regimens. We hypothesized that both modifications, i.e., the addition of clofazimine and the replacement of rifampin with high-dose rifapentine, in the first-line regimen for drug-susceptible TB would significantly shorten the duration of treatment necessary for cure. We tested this hypothesis in a well-established BALB/c mouse model of TB chemotherapy and also in a C3HeB/FeJ mouse model in which mice can develop caseous necrotic lesions, an environment where rifapentine and clofazimine may individually be less effective. In both mouse models, replacing rifampin with high-dose rifapentine and adding clofazimine in the first-line regimen resulted in greater bactericidal and sterilizing activity than either modification alone, suggesting that a rifapentine- and clofazimine-containing regimen may have the potential to significantly shorten the treatment duration for drug-susceptible TB. These data provide preclinical evidence supporting the evaluation of regimens combining high-dose rifapentine and clofazimine in clinical trials.
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Affiliation(s)
- Vikram Saini
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Nicole C Ammerman
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Yong Seok Chang
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Rokeya Tasneen
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Richard E Chaisson
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Sanjay Jain
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Eric Nuermberger
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jacques H Grosset
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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7
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Impact of Clofazimine Dosing on Treatment Shortening of the First-Line Regimen in a Mouse Model of Tuberculosis. Antimicrob Agents Chemother 2018; 62:AAC.00636-18. [PMID: 29735562 DOI: 10.1128/aac.00636-18] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 04/30/2018] [Indexed: 01/17/2023] Open
Abstract
The antileprosy drug clofazimine was recently repurposed as part of a newly endorsed short-course regimen for multidrug-resistant tuberculosis. It also enables significant treatment shortening when added to the first-line regimen for drug-susceptible tuberculosis in a mouse model. However, clofazimine causes dose- and duration-dependent skin discoloration in patients, and the optimal clofazimine dosing strategy in the context of the first-line regimen is unknown. We utilized a well-established mouse model to systematically address the impacts of duration, dose, and companion drugs on the treatment-shortening activity of clofazimine in the first-line regimen. In all studies, the primary outcome was relapse-free cure (culture-negative lungs) 6 months after stopping treatment, and the secondary outcome was bactericidal activity, i.e., the decline in the lung bacterial burden during treatment. Our findings indicate that clofazimine activity is most potent when coadministered with first-line drugs continuously throughout treatment and that equivalent treatment-shortening results are obtained with half the dose commonly used in mice. However, our studies also suggest that clofazimine at low exposures may have negative impacts on treatment outcomes, an effect that was evident only after the first 3 months of treatment. These data provide a sound evidence base to inform clofazimine dosing strategies to optimize the antituberculosis effect while minimizing skin discoloration. The results also underscore the importance of conducting long-term studies to allow the full evaluation of drugs administered in combination over long durations.
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8
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Murugesan D, Ray PC, Bayliss T, Prosser GA, Harrison JR, Green K, Soares de Melo C, Feng TS, Street LJ, Chibale K, Warner DF, Mizrahi V, Epemolu O, Scullion P, Ellis L, Riley J, Shishikura Y, Ferguson L, Osuna-Cabello M, Read KD, Green SR, Lamprecht DA, Finin PM, Steyn AJC, Ioerger TR, Sacchettini J, Rhee KY, Arora K, Barry CE, Wyatt PG, Boshoff HIM. 2-Mercapto-Quinazolinones as Inhibitors of Type II NADH Dehydrogenase and Mycobacterium tuberculosis: Structure-Activity Relationships, Mechanism of Action and Absorption, Distribution, Metabolism, and Excretion Characterization. ACS Infect Dis 2018. [PMID: 29522317 PMCID: PMC5996347 DOI: 10.1021/acsinfecdis.7b00275] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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Mycobacterium tuberculosis (MTb) possesses
two nonproton pumping type II NADH dehydrogenase (NDH-2)
enzymes which are predicted to be jointly essential for respiratory
metabolism. Furthermore, the structure of a closely related bacterial
NDH-2 has been reported recently, allowing for the structure-based
design of small-molecule inhibitors. Herein, we disclose MTb whole-cell structure–activity relationships (SARs) for a series of 2-mercapto-quinazolinones which target the ndh encoded NDH-2 with nanomolar potencies. The compounds were inactivated by glutathione-dependent adduct formation as well as quinazolinone oxidation in microsomes. Pharmacokinetic studies demonstrated modest bioavailability and compound exposures. Resistance to the compounds in MTb was conferred by promoter mutations in the alternative nonessential NDH-2 encoded by ndhA in MTb. Bioenergetic analyses revealed a decrease in oxygen consumption rates in response to inhibitor in cells in which membrane potential was uncoupled from ATP production, while inverted membrane vesicles showed mercapto-quinazolinone-dependent inhibition of ATP production when NADH was the electron donor to the respiratory chain. Enzyme kinetic studies further demonstrated noncompetitive inhibition, suggesting binding of this scaffold to an allosteric site. In summary, while the initial MTb SAR showed limited improvement in potency, these results, combined with structural information on the bacterial protein, will aid in the future discovery of new and improved NDH-2 inhibitors.
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Affiliation(s)
- Dinakaran Murugesan
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, United Kingdom
| | - Peter C. Ray
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, United Kingdom
| | - Tracy Bayliss
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, United Kingdom
| | - Gareth A. Prosser
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Disease, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Justin R. Harrison
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, United Kingdom
| | - Kirsteen Green
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, United Kingdom
| | - Candice Soares de Melo
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch, 7701, South Africa
| | - Tzu-Shean Feng
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch, 7701, South Africa
| | - Leslie J. Street
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch, 7701, South Africa
| | - Kelly Chibale
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch, 7701, South Africa
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch, 7701, South Africa
- South African Medical Research Council Drug Discovery and Development Research Unit, Department of Chemistry, University of Cape Town, Rondebosch, 7701, South Africa
| | - Digby F. Warner
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch, 7701, South Africa
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Rondebosch, 7701, South Africa
| | - Valerie Mizrahi
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch, 7701, South Africa
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Rondebosch, 7701, South Africa
| | - Ola Epemolu
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, United Kingdom
| | - Paul Scullion
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, United Kingdom
| | - Lucy Ellis
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, United Kingdom
| | - Jennifer Riley
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, United Kingdom
| | - Yoko Shishikura
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, United Kingdom
| | - Liam Ferguson
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, United Kingdom
| | - Maria Osuna-Cabello
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, United Kingdom
| | - Kevin D. Read
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, United Kingdom
| | - Simon R. Green
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, United Kingdom
| | - Dirk A. Lamprecht
- Africa Health Research Institute (AHRI), K-RITH Tower Building Level 3, 719 Umbilo Road, Durban, 4001, South Africa
| | - Peter M. Finin
- Africa Health Research Institute (AHRI), K-RITH Tower Building Level 3, 719 Umbilo Road, Durban, 4001, South Africa
| | - Adrie J. C. Steyn
- Africa Health Research Institute (AHRI), K-RITH Tower Building Level 3, 719 Umbilo Road, Durban, 4001, South Africa
- Department of Microbiology, University of Alabama at Birmingham, 1720 Second Avenue South, Birmingham, Alabama 35294-2170, United States
| | - Thomas R. Ioerger
- Department of Computer Science and Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Jim Sacchettini
- Department of Computer Science and Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Kyu Y. Rhee
- Division of Infectious Diseases, Weill Department of Medicine, Weill Cornell Medical College, New York, New York 10065, United States
| | - Kriti Arora
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Disease, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Clifton E. Barry
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Disease, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch, 7701, South Africa
| | - Paul G. Wyatt
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, United Kingdom
| | - Helena I. M. Boshoff
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Disease, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
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9
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Gomez GB, Dowdy DW, Bastos ML, Zwerling A, Sweeney S, Foster N, Trajman A, Islam MA, Kapiga S, Sinanovic E, Knight GM, White RG, Wells WA, Cobelens FG, Vassall A. Cost and cost-effectiveness of tuberculosis treatment shortening: a model-based analysis. BMC Infect Dis 2016; 16:726. [PMID: 27905897 PMCID: PMC5131398 DOI: 10.1186/s12879-016-2064-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 11/08/2016] [Indexed: 12/05/2022] Open
Abstract
Background Despite improvements in treatment success rates for tuberculosis (TB), current six-month regimen duration remains a challenge for many National TB Programmes, health systems, and patients. There is increasing investment in the development of shortened regimens with a number of candidates in phase 3 trials. Methods We developed an individual-based decision analytic model to assess the cost-effectiveness of a hypothetical four-month regimen for first-line treatment of TB, assuming non-inferiority to current regimens of six-month duration. The model was populated using extensive, empirically-collected data to estimate the economic impact on both health systems and patients of regimen shortening for first-line TB treatment in South Africa, Brazil, Bangladesh, and Tanzania. We explicitly considered ‘real world’ constraints such as sub-optimal guideline adherence. Results From a societal perspective, a shortened regimen, priced at USD1 per day, could be a cost-saving option in South Africa, Brazil, and Tanzania, but would not be cost-effective in Bangladesh when compared to one gross domestic product (GDP) per capita. Incorporating ‘real world’ constraints reduces cost-effectiveness. Patient-incurred costs could be reduced in all settings. From a health service perspective, increased drug costs need to be balanced against decreased delivery costs. The new regimen would remain a cost-effective option, when compared to each countries’ GDP per capita, even if new drugs cost up to USD7.5 and USD53.8 per day in South Africa and Brazil; this threshold was above USD1 in Tanzania and under USD1 in Bangladesh. Conclusion Reducing the duration of first-line TB treatment has the potential for substantial economic gains from a patient perspective. The potential economic gains for health services may also be important, but will be context-specific and dependent on the appropriate pricing of any new regimen. Electronic supplementary material The online version of this article (doi:10.1186/s12879-016-2064-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- G B Gomez
- Amsterdam Institute for Global Health and Development and Department of Global Health, Academic Medical Center, University of Amsterdam, Trinity Building C, Pietersbergweg 17, Amsterdam, 1105 BM, The Netherlands. .,Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK.
| | - D W Dowdy
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
| | - M L Bastos
- Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Tuberculosis Scientific League, Rio de Janeiro, Brazil
| | - A Zwerling
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
| | - S Sweeney
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
| | - N Foster
- Health Economics Unit, School of Public Health & Family Medicine, University of Cape Town, Cape Town, South Africa
| | - A Trajman
- Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Tuberculosis Scientific League, Rio de Janeiro, Brazil.,McGill University, Montreal, Canada
| | - M A Islam
- BRAC Health Nutrition and Population Programme, BRAC Centre, Dhaka, Bangladesh
| | - S Kapiga
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
| | - E Sinanovic
- Health Economics Unit, School of Public Health & Family Medicine, University of Cape Town, Cape Town, South Africa
| | - G M Knight
- TB Modelling Group, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - R G White
- TB Modelling Group, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - W A Wells
- Global Alliance for TB Drug Development, New York, USA.,Present address: United States Agency for International Development, Washington, DC, USA
| | - F G Cobelens
- Amsterdam Institute for Global Health and Development and Department of Global Health, Academic Medical Center, University of Amsterdam, Trinity Building C, Pietersbergweg 17, Amsterdam, 1105 BM, The Netherlands.,KNCV Tuberculosis Foundation, The Hague, Netherlands
| | - A Vassall
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
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10
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Milstein M, Lecca L, Peloquin C, Mitchison D, Seung K, Pagano M, Coleman D, Osso E, Coit J, Vargas Vasquez DE, Sanchez Garavito E, Calderon R, Contreras C, Davies G, Mitnick CD. Evaluation of high-dose rifampin in patients with new, smear-positive tuberculosis (HIRIF): study protocol for a randomized controlled trial. BMC Infect Dis 2016; 16:453. [PMID: 27567500 PMCID: PMC5002098 DOI: 10.1186/s12879-016-1790-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 08/18/2016] [Indexed: 11/10/2022] Open
Abstract
Background Evidence has existed for decades that higher doses of rifampin may be more effective, but potentially more toxic, than standard doses used in tuberculosis treatment. Whether increased doses of rifampin could safely shorten treatment remains an open question. Methods/Design The HIRIF study is a phase II randomized trial comparing rifampin doses of 20 and 15 mg/kg/day to the standard 10 mg/kg/day for the first 2 months of tuberculosis treatment. All participants receive standard doses of companion drugs and a standard continuation-phase treatment (4 months, 2 drugs). They are followed for 6 months post treatment. Study participants are adults with newly diagnosed, previously untreated, smear positive (≥2+) pulmonary tuberculosis. The primary outcome is rifampin area under the plasma concentration-time curve (AUC0–24) after at least 14 days of study treatment/minimum inhibitory concentration. 180 randomized participants affords 90 % statistical power to detect a difference of at least 14 mcg/mL*hr between the 20 mg/kg group and the 10 mg/kg group, assuming a loss to follow-up of up to 17 %. Discussion Extant evidence suggests the potential for increased doses of rifampin to shorten tuberculosis treatment duration. Early studies that explored this potential using intermittent, higher dosing were derailed by toxicity. Given the continued large, global burden of tuberculosis with nearly 10 million new cases annually, shortened regimens with existing drugs would offer an important advantage to patients and health systems. Trial registration This trial was registered with clinicaltrials.gov (registration number: NCT01408914) on 2 August 2011.
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Affiliation(s)
| | - Leonid Lecca
- Partners In Health, Boston, MA, 02215, USA.,Socios En Salud, Sucursal-Peru, Lima, Peru
| | | | | | - Kwonjune Seung
- Partners In Health, Boston, MA, 02215, USA.,Brigham and Women's Hospital, Boston, MA, USA
| | | | | | - Elna Osso
- Harvard Medical School, Boston, MA, 02118, USA
| | - Julia Coit
- Harvard Medical School, Boston, MA, 02118, USA
| | | | | | - Roger Calderon
- Partners In Health, Boston, MA, 02215, USA.,Socios En Salud, Sucursal-Peru, Lima, Peru
| | - Carmen Contreras
- Partners In Health, Boston, MA, 02215, USA.,Socios En Salud, Sucursal-Peru, Lima, Peru
| | | | - Carole D Mitnick
- Harvard Medical School, Boston, MA, 02118, USA. .,Partners In Health, Boston, MA, 02215, USA.
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11
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Trajman A, Bastos ML, Belo M, Calaça J, Gaspar J, Dos Santos AM, Dos Santos CM, Brito RT, Wells WA, Cobelens FG, Vassall A, Gomez GB. Shortened first-line TB treatment in Brazil: potential cost savings for patients and health services. BMC Health Serv Res 2016; 16:27. [PMID: 26800677 PMCID: PMC4722708 DOI: 10.1186/s12913-016-1269-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 01/12/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Shortened treatment regimens for tuberculosis are under development to improve treatment outcomes and reduce costs. We estimated potential savings from a societal perspective in Brazil following the introduction of a hypothetical four-month regimen for tuberculosis treatment. METHODS Data were gathered in ten randomly selected health facilities in Rio de Janeiro. Health service costs were estimated using an ingredient approach. Patient costs were estimated from a questionnaire administered to 126 patients. Costs per visits and per case treated were analysed according to the type of therapy: self-administered treatment (SAT), community- and facility-directly observed treatment (community-DOT, facility-DOT). RESULTS During the last 2 months of treatment, the largest savings could be expected for community-DOT; on average USD 17,351-18,203 and USD 43,660-45,856 (bottom-up and top-down estimates) per clinic. Savings to patients could also be expected as the median (interquartile range) patient-related costs during the two last months were USD 108 (13-291), USD 93 (36-239) and USD 11 (7-126), respectively for SAT, facility-DOT and community-DOT. CONCLUSION Introducing a four-month regimen may result in significant cost savings for both the health service and patients, especially the poorest. In particular, a community-DOT strategy, including treatment at home, could maximise health services savings while limiting patient costs. Our cost estimates are likely to be conservative because a 4-month regimen could hypothetically increase the proportion of patients cured by reducing the number of patients defaulting and we did not include the possible cost benefits from the subsequent prevention of costs due to downstream transmission averted and rapid clinical improvement with less side effects in the last two months.
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Affiliation(s)
- Anete Trajman
- Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. .,McGill University, Montreal, Canada. .,Tuberculosis Scientific League, Rio de Janeiro, Brazil.
| | - Mayara Lisboa Bastos
- Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Tuberculosis Scientific League, Rio de Janeiro, Brazil
| | - Marcia Belo
- Tuberculosis Scientific League, Rio de Janeiro, Brazil.,Souza Marques Foundation, Rio de Janeiro, Brazil
| | | | - Júlia Gaspar
- Tuberculosis Scientific League, Rio de Janeiro, Brazil
| | | | | | | | - William A Wells
- Global Alliance for TB Drug Development, New York, USA.,Current address: United States Agency for International Development, Washington, DC, USA
| | - Frank G Cobelens
- Amsterdam Institute for Global Health and Development and Department of Global Health, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Anna Vassall
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
| | - Gabriela B Gomez
- Amsterdam Institute for Global Health and Development and Department of Global Health, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
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12
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The Impact and Cost-Effectiveness of a Four-Month Regimen for First-Line Treatment of Active Tuberculosis in South Africa. PLoS One 2015; 10:e0145796. [PMID: 26717007 PMCID: PMC4696677 DOI: 10.1371/journal.pone.0145796] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 12/08/2015] [Indexed: 01/26/2023] Open
Abstract
Background A 4-month first-line treatment regimen for tuberculosis disease (TB) is expected to have a direct impact on patient outcomes and societal costs, as well as an indirect impact on Mycobacterium tuberculosis transmission. We aimed to estimate this combined impact in a high TB-burden country: South Africa. Method An individual based M. tb transmission model was fitted to the TB burden of South Africa using a standard TB natural history framework. We measured the impact on TB burden from 2015–2035 of introduction of a non-inferior 4-month regimen replacing the standard 6-month regimen as first-line therapy. Impact was measured with respect to three separate baselines (Guidelines, Policy and Current), reflecting differences in adherence to TB and HIV treatment guidelines. Further scenario analyses considered the variation in treatment-related parameters and resistance levels. Impact was measured in terms of differences in TB burden and Disability Adjusted Life Years (DALYs) averted. We also examined the highest cost at which the new regimen would be cost-effective for several willingness-to-pay thresholds. Results It was estimated that a 4-month regimen would avert less than 1% of the predicted 6 million person years with TB disease in South Africa between 2015 and 2035. A similarly small impact was seen on deaths and DALYs averted. Despite this small impact, with the health systems and patient cost savings from regimen shortening, the 4-month regimen could be cost-effective at $436 [NA, 5983] (mean [range]) per month at a willingness-to-pay threshold of one GDP per capita ($6,618). Conclusion The introduction of a non-inferior 4-month first-line TB regimen into South Africa would have little impact on the TB burden. However, under several scenarios, it is likely that the averted societal costs would make such a regimen cost-effective in South Africa.
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13
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Abstract
Purine and pyrimidine nucleoside and nucleotide analogs have been extensively studied as anticancer and antiviral agents. In addition to this, they have recently shown great potential against Mycobacterium Tuberculosis, the causative agent of TB. TB ranks as the tenth most common cause of death in the world. The current treatment for TB infection is limited by side effects and cost of the drugs and most importantly by the development of resistance to the therapy. Therefore the development of novel drugs, capable of overcoming the drawbacks of the existing treatments, has become the focus of many research programs. In parallel to that, a tremendous effort has been made to elucidate the unique metabolism of this pathogen with the aim to identify new possible targets. This review presents the state of the art in nucleoside and nucleotide analogs in the treatment of TB. In particular, we report on the inhibitory activity of this class of compounds, both in enzymatic and whole-cell assays, providing a brief insight to which reported target these novel compounds are hitting.
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14
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A sterilizing tuberculosis treatment regimen is associated with faster clearance of bacteria in cavitary lesions in marmosets. Antimicrob Agents Chemother 2015; 59:4181-9. [PMID: 25941223 DOI: 10.1128/aac.00115-15] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 04/28/2015] [Indexed: 01/09/2023] Open
Abstract
Shortening the lengthy treatment duration for tuberculosis patients is a major goal of current drug development efforts. The common marmoset develops human-like disease pathology and offers an attractive model to better understand the basis for relapse and test regimens for effective shorter duration therapy. We treated Mycobacterium tuberculosis-infected marmosets with two drug regimens known to differ in their relapse rates in human clinical trials: the standard four-drug combination of isoniazid, rifampin, pyrazinamide, and ethambutol (HRZE) that has very low relapse rates and the combination of isoniazid and streptomycin that is associated with higher relapse rates. As early as 2 weeks, the more sterilizing regimen significantly reduced the volume of lung disease by computed tomography (P = 0.035) and also significantly reduced uptake of [(18)F]-2-fluoro-2-deoxyglucose by positron emission tomography (P = 0.049). After 6 weeks of therapy, both treatments caused similar reductions in granuloma bacterial load, but the more sterilizing, four-drug regimen caused greater reduction in bacterial load in cavitary lesions (P = 0.009). These findings, combined with the association in humans between cavitary disease and relapse, suggest that the basis for improved sterilizing activity of the four-drug combination is both its faster disease volume resolution and its stronger sterilizing effect on cavitary lesions. Definitive data from relapse experiments are needed to support this observation.
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15
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Novel dosing strategies increase exposures of the potent antituberculosis drug rifapentine but are poorly tolerated in healthy volunteers. Antimicrob Agents Chemother 2015; 59:3399-405. [PMID: 25824215 DOI: 10.1128/aac.05128-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 03/20/2015] [Indexed: 11/20/2022] Open
Abstract
Rifapentine is a potent antituberculosis drug currently in phase III trials. Bioavailability decreases with increasing dose, yet high daily exposures are likely needed to improve efficacy and shorten the tuberculosis treatment duration. Further, the limits of tolerability are poorly defined. The phase I multicenter trial in healthy adults described here investigated two strategies to increase rifapentine exposures: dividing the dose or giving the drug with a high-fat meal. In arm 1, rifapentine was administered at 10 mg/kg of body weight twice daily and 20 mg/kg once daily, each for 14 days, separated by a 28-day washout; the dosing sequence was randomized. In arm 2, 15 mg/kg rifapentine once daily was given with a high-fat versus a low-fat breakfast. Sampling for pharmacokinetic analysis was performed on days 1 and 14. Population pharmacokinetic analyses were performed. This trial was stopped early for poor tolerability and because of safety concerns. Of 44 subjects, 20 discontinued prematurely; 11 of these discontinued for protocol-defined toxicity (a grade 3 or higher adverse event or grade 2 or higher rifamycin hypersensitivity). Taking rifapentine with a high-fat meal increased the median steady-state area under the concentration-time curve from time zero to 24 h (AUC0-24ss) by 31% (relative standard error, 6%) compared to that obtained when the drug was taken with a low-fat breakfast. Dividing the dose increased exposures substantially (e.g., 38% with 1,500 mg/day). AUC0-24ss was uniformly higher in our study than in recent tuberculosis treatment trials, in which toxicity was rare. In conclusion, two strategies to increase rifapentine exposures, dividing the dose or giving it with a high-fat breakfast, successfully increased exposures, but toxicity was common in healthy adults. The limits of tolerability in patients with tuberculosis remain to be defined. (AIDS Clinical Trials Group study A5311 has been registered at ClinicalTrials.gov under registration no. NCT01574638.).
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16
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Fofana MO, Knight GM, Gomez GB, White RG, Dowdy DW. Population-level impact of shorter-course regimens for tuberculosis: a model-based analysis. PLoS One 2014; 9:e96389. [PMID: 24816692 PMCID: PMC4015982 DOI: 10.1371/journal.pone.0096389] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 04/07/2014] [Indexed: 11/19/2022] Open
Abstract
Despite current control efforts, global tuberculosis (TB) incidence is decreasing slowly. New regimens that can shorten treatment hold promise for improving treatment completion and success, but their impact on population-level transmission remains unclear. Earlier models projected that a four-month regimen could reduce TB incidence by 10% but assumed that an entire course of therapy must be completed to derive any benefit. We constructed a dynamic transmission model of TB disease calibrated to global estimates of incidence, prevalence, mortality, and treatment success. To account for the efficacy of partial treatment, we used data from clinical trials of early short-course regimens to estimate relapse rates among TB patients who completed one-third, one-half, two-thirds, and all of their first-line treatment regimens. We projected population-level incidence and mortality over 10 years, comparing standard six-month therapy to hypothetical shorter-course regimens with equivalent treatment success but fewer defaults. The impact of hypothetical four-month regimens on TB incidence after 10 years was smaller than estimated in previous modeling analyses (1.9% [95% uncertainty range 0.6-3.1%] vs. 10%). Impact on TB mortality was larger (3.5% at 10 years) but still modest. Transmission impact was most sensitive to the proportion of patients completing therapy: four-month therapy led to greater incidence reductions in settings where 25% of patients leave care ("default") over six months. Our findings remained robust under one-way variation of model parameters. These findings suggest that novel regimens that shorten treatment duration may have only a modest effect on TB transmission except in settings of very low treatment completion.
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Affiliation(s)
- Mariam O. Fofana
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- Medical Scientist Training Program, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Gwenan M. Knight
- TB Modelling Group, TB Centre and Centre for the Mathematical Modelling of Infectious Diseases, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Gabriela B. Gomez
- Department of Global Health, University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands
| | - Richard G. White
- TB Modelling Group, TB Centre and Centre for the Mathematical Modelling of Infectious Diseases, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - David W. Dowdy
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
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