Insights into the use of cytochrome bc1 inhibitors for future therapeutic strategies for tuberculosis

Insights into the use of cytochrome bc1 inhibitors for future therapeutic strategies for tuberculosis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Brief Communication Insights into the use of cytochrome bc1 inhibitors for future therapeutic strategies for tuberculosis Clara Aguilar Pérez, Anne Lenaerts, Cristina Villellas, Jerome Guillemont, and 32 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5331796/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 22 Oct, 2025 Read the published version in Nature Communications → Version 1 posted You are reading this latest preprint version Abstract Recent efforts to improve tuberculosis (TB) treatment options have focused on developing molecules with novel mechanisms of action and identifying optimal treatment regimens. Inhibition of Mycobacterium tuberculosis cytochrome bc1 oxidase has emerged as a promising therapeutic target that could potentially contribute to improved TB combination regimens. Using a relapsing mouse model, we demonstrate that cytochrome bc1 inhibitors could serve as effective partner drugs, enhancing regimen sterilisation. We propose several novel regimen strategies for both multidrug-resistant TB (MDR-TB) and drug-sensitive TB (DS-TB), where cytochrome bc1 inhibitors contribute to sterilisation and treatment shortening. Additionally, we show that clinical isolates exhibit heightened susceptibility to cytochrome bc1 inhibitors compared to laboratory-adapted strains, further supporting their translational potential. These findings suggest that cytochrome bc1 inhibitors have significant potential to improve TB treatment outcomes and highlight the need for further studies to evaluate their clinical contribution to novel treatment regimens. Health sciences/Diseases/Infectious diseases/Tuberculosis Biological sciences/Microbiology/Antimicrobials/Antibiotics Biological sciences/Microbiology/Antimicrobials/Antimicrobial resistance Figures Figure 1 Figure 2 Full Text The global response to the tuberculosis (TB) epidemic has been exacerbated by the emergence of multidrug-resistant TB (MDR-TB). Combination treatment for TB is essential to prevent drug resistance, ensure complete eradication of the bacteria, and improve treatment effectiveness; however, current regimens still require many months of treatment. The World Health Organisation’s consolidated guidelines include new recommendations for treatment shortening 1,2 . These recommendations suggest two six-month regimen options (compared to the previous 9 to 18-month duration): BPaLM (bedaquiline, pretomanid, linezolid and moxifloxacin) for ages 14 years and older, and BDLLfxC (bedaquiline, delamanid, linezolid, levofloxacin and clofazimine) for children, adolescents, adults and pregnant women. The central role that fluoroquinolones (FQ) and linezolid play in those regimens pose serious limitations due to drug resistance and toxicity, respectively. Moxifloxacin (M) or levofloxacin (Lfx) must be excluded in cases of fluoroquinolone resistance 3 , modifying the regimens to BPaL and BDLC, respectively. Furthermore, the use of linezolid in MDR-TB treatment is often associated with adverse events, such as myelosuppression and peripheral neuropathy, which may negatively impact patient adherence and require regimen modification 4 . While MDR-TB treatment options are diversifying and improving 5 , emerging drug resistance adds additional concerns, underscoring the urgent need to discover compounds with novel modes of action (MoA) and develop novel therapeutic approaches. The discovery of Q203 (telacebec, T; Supplementary Figure S1 ) and its successful Phase 2A Early Bactericidal Activity (EBA) trial has highlighted the inhibition of the cytochrome bc 1 complex of Mycobacterium tuberculosis as a promising new molecular target 6-8 . The cytochrome bc 1 complex is a crucial part of the electron transport chain, essential for ATP production, potentially making an inhibitor of cytochrome bc 1 a good partner drug for other inhibitors of oxidative phosphorylation such as bedaquiline. Despite this potential, currently, there is limited demonstration of the specific role cytochrome bc 1 inhibitors could play in future TB treatment regimens 9 . Here, using relapsing mouse models, we assessed the contribution of a validated cytochrome bc 1 inhibitor tool compound (JNJ-2901, J) in different treatment regimen strategies with special focus on combinations devoid of FQ-resistance liability or linezolid-associated toxicity ( Figure 1A , Supplementary Figure S1-2, Supplementary Table S1-3 ). In the TB-PRACTECAL trial, the BPaLC (bedaquiline, pretomanid, linezolid and clofazimine) regimen resulted in a higher proportion of MDR-TB patients with favourable outcomes (81%) compared to BPaL (77%) and standard of care (SoC; 52%), primarily due to early treatment discontinuation from adverse events in the SoC group 10 . Given the adverse effects associated with the use of linezolid in the treatment of MDR-TB, there is growing interest in identifying alternative partner drugs 11-13 .Here, using a mouse model, we show that a regimen including a cytochrome bc 1 inhibitor could serve as a promising alternative ( Figure 1B-C ; Supplementary Table S4-7 ;Studies A and B). Although BPaL, the regimen recommended for fluoroquinolone-resistant MDR-TB, led to a greater decrease in colony forming units (CFU) after 8 weeks compared to BPaJ, comparable relapse rates (measured after 3 months post treatment) were observed after 8 weeks (86.6%-100% for BPaL, 100% for BPaJ) and 12 weeks of treatment (26.6% for both regimens). Replacing linezolid with clofazimine resulted in a similar decrease in CFU after 8 weeks but led to fewer relapses post-treatment (86.6%-100% for BPaL, 26.6-66.6% for BPaC). BPaCJ demonstrated the best bactericidal effect, achieving an additional 1 log 10 decrease in CFU compared to BPaC after 8 weeks, translating to a 33% relapse rate. No relapses occurred after 12 weeks of treatment with either BPaC or BPaCJ, highlighting the potential for treatment shortening compared to the BPaL SoC ( Figure 1B-C; Supplementary Table S4-7 ). Interestingly, addition of JNJ-2901 to a moxifloxacin-containing regimen (BPaMJ) did not lead to a further decrease in bacterial burden or in relapse rate compared with BPaM ( Figure 1B; Supplementary Table S4-7 ). Our findings demonstrate that combining a cytochrome bc 1 inhibitor with BPaC increases the sterilising activity compared to BPaC alone, suggesting that cytochrome bc 1 inhibitors could play an important role in future MDR-TB regimens. In an additional study (Study C), JNJ-2901 reduced the relapse rate when combined with the BPaL regimen, despite an inability to rescue mice when administered as a monotherapy in an intravenous model using the H37Rv reference strain ( Supplementary Figure S3 ). There was a trend towards improvement of both the bacterial burden (BPaLJ: 0.95 ± 1.1 vs BPaL: 2.06 ± 1.3 log 10 CFU lung -1 , p =0.04) and a quantifiable improvement in relapse rates, that failed to reach statistical significance within the limitations of this trial design (50% vs 89%, p >0.05), while BPaLJ was comparable to BPaLM and BPaMZ ( Supplementary Table S8-10 ). This suggests that BPaLJ could be considered as a potential treatment regimen irrespective of fluoroquinolone susceptibility. In a further study, an alternative dosing strategy was used where mice were treated with BPaL for 8 weeks during an initial phase, followed by an additional 8 weeks of either BPa, BJ, B or no treatment in a continuation phase. The rationale for this study design was to reduce the time and overall amount of drug required to reach bacterial sterility. Bacterial burdens in lungs were assessed after 8, 12 and 16 weeks, and relapse rates were measured after 16 weeks of treatment plus 16 weeks following treatment cessation ( Figure 1D; Supplementary Table S11 ; Study D). Both the BPaL/BPa and BPaL/BJ regimens trended towards lower relapse rates compared to BPaL without continuation treatment, although this was not statistically significant ( p -value=0.09). No colonies were detected after 12 weeks of treatment with BPaL/BJ, whereas with BPaL/B, colonies were detected from 3/5 mice at the end of treatment. These results suggest that inclusion of a cytochrome bc 1 inhibitor could enhance regimen effectiveness during the continuation phase of treatment with fewer drugs and a reduced overall drug burden. Effective regimens require drugs with both bactericidal and sterilising activities to rapidly reduce bacterial loads and kill drug-tolerant bacilli. Drugs in the continuation phase must target drug-tolerant bacteria that survive the initial intensive phase 14 . A two-phase regimen, with an initial phase of drugs that rapidly reduce bacterial burdens, followed by sterilising drugs in a continuation phase, is a proven strategy for improving treatment outcomes for patients. The inclusion of a cytochrome bc 1 inhibitor in the continuation phase of the BPaL/BJ regimen demonstrated a sterilising effect similar to that of the BPaL/BPa regimen, suggesting that a cytochrome bc 1 inhibitor could serve as an effective alternative to pretomanid (Pa). Next, we focused on an ultra-short treatment strategy for drug sensitive-TB (DS-TB) based on drugs targeting the respiratory pathway. For this purpose, we assessed the efficacy of regimens containing telacebec alongside other drugs targeting the respiratory pathway, compared to the current DS-TB SoC; isoniazid, rifampicin, pyrazinamide, and ethambutol (HRZE; Study E). BCZ, CZT and BCZT regimens all demonstrated superior efficacy over HRZE after 8 weeks of treatment in reducing lung CFU burdens ( Figure 2A, Supplementary Tables S12-14 ; Study E). Both BCZ and BCZT regimens achieved 0% relapse rates 12 weeks after 6- and 8-weeks of treatment, whereas CZT required at least 12 weeks of treatment to achieve 0% relapse. One of the mice treated with HRZE remained culture positive even after 20 weeks of treatment. The benefit of adding telacebec to BCZ is highlighted by the relapse rates after 4 weeks treatment: BCZ (60%) vs. BCZT (36%), underscoring the treatment-shortening potential of cytochrome bc 1 inhibitors in combination with other drugs targeting the electron transport chain. Based on the TRUNCATE-TB trial strategy, a 2-month BZ-containing regimen could be as effective as the current 6-month standard (HRZE) 15 . Adding telacebec to the CZ core regimen reduced bacterial load by 2.2 log 10 CFU in this model and, including telacebec in CZ or BCZ regimens significantly shortened treatment compared to HRZE. These findings provide strong evidence that incorporating a cytochrome bc 1 inhibitor into new treatment regimens offers substantial benefits which should be further investigated. We found that the impact of cytochrome bc 1 inhibitors may be underrepresented depending on the M. tuberculosis strain selected for investigation. Here, using another cytochrome bc 1 inhibitor, JNJ-4052, we demonstrate that a diverse range of clinical isolates from infected patients exhibited increased susceptibility to cytochrome bc 1 inhibitors in both minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays when compared to the lab-adapted H37Rv strain( Figures 2B-E; Supplementary Table S15 ). This heightened susceptibility translated into increased in vivo efficacy in an acute mouse model, where a statistically significant CFU reduction (1.6 log 10 reduction; p <0.01) was observed following cytochrome bc 1 inhibitor (JNJ-4052) treatment in mice inoculated with a clinical isolate ( Figure 2F; Supplementary Tables S1-S3 ; Study F). Further work is needed to determine whether the routine use of clinical isolates should be incorporated into regimen design studies. Indeed, similar findings have recently been reported 16 , showing that the clinical isolate HN878 is more susceptible to cytochrome bc 1 inhibitors, with a notable contribution when added to BPaC, resulting in a 2-log reduction in lung bacterial burden between BPaC and BPaCT, after 4 weeks of treatment. These results further emphasise the relevance of clinical isolates for evaluating the in vivo efficacy of new compounds. Together, our findings suggest that cytochrome bc 1 inhibitors could play a crucial role in future TB treatment regimens. Specifically, cytochrome bc 1 inhibitors may serve as effective replacements for linezolid in SoC regimens for MDR- and fluoroquinolone-resistant MDR-TB. As this represents a novel MoA, it could also help raise the barrier to resistance development to other components of the regimen and could be use for treatment of DS-TB. Our experiments containing a treatment phase followed by a continuation phase may also benefit future formulation strategies such as long acting injectables (LAI) providing an alternative strategy to improve treatment outcomes. Finally, drug repurposing has proven to be an effective strategy for accelerating the discovery of new treatments; linezolid, for example, was originally developed for vancomycin-resistant enterococcal infections. Our data highlight the potential of both clofazimine- and cytochrome bc 1 inhibitor-containing regimens to significantly shorten treatment durations for both DS- and DR-TB. Declarations Acknowledgements The authors would like to thank: Amit Kaushik for technical support at Johns Hopkins University; AT Henze and PM Petrar for medical writing support at Janssen Pharmaceutica; Annelies Wouter and Lieve Lammens for toxicology input at Janssen Pharmaceutica; Nadia Neto for her feedback on WGS at Janssen Pharmaceutica; Gregory Bancroft for his intellectual input at the London School of Hygiene & Tropical Medicine; and Courtney I. Hastings at Colorado State University for technical support. Author contributions CAP, DAL, AJL, SS, GTR, NL, AU, NV, ELN, NCA AA, AC BB, LB, HP, JD and ASP were involved in the conception or the design of the study. JG and JMB designed and synthesised the compounds. AK, CV, DAL, BB, ASP and LBallell supervised the overall research programme. CAP, SS, ELN, AC, NCA, TCM, SW, NV, NW, HP, JD, AH, BS, LBrock, GG and GR participated in the collection or generation of the studies data. SS, EN, AC, TCM, SW, HP, JD, AH, VG and GTR performed the studies. CAP, SS, ELN, JE, TGC and GR contributed to the study with materials/analysis tools. CAP, AJL, NV, SW, GTR, SS, MC, ELN, NCA, LBallell, JD, HP, VC, BS, RJW and DAL were involved in the analysis or interpretation of the data. CAP, RJW and DAL wrote the manuscript. All authors reviewed and commented drafts of the manuscript for intellectual content and gave final approval to submit for publication. All authors attest they meet the ICMJE criteria for authorship. Data availability All data generated or analysed during this study are included in this published article (and its supplementary information files). Conflict of interest statement JG, CV and DAL have been named inventors in a patent application for JNJ-2901 and JNJ-4052 compounds. CAP, CV, JG, MC, JE, NL, BS, JMB, VC, LBallell, BB, AK, ASP and DAL were/are all full-time employees of Janssen, a Johnson & Johnson company, and/or potential stockholders of Johnson & Johnson. The other authors declare no competing interests. Funding statement This work was supported by Janssen Pharmaceutica NV, including all costs associated with the development and publishing of the manuscript. The work at the London School of Hygiene & Tropical Medicine was supported by funding from Janssen Pharmaceutica. This project has received funding from the Innovative Medicines Initiative 2 Joint Undertaking under grant agreement No 853903 (RespiriTB). This Joint Undertaking receives support from the European Union’s Horizon 2020 research and innovation programme and EFPIA. References World Health Organisation, WHO consolidated guidelines on tuberculosis. Module 4: treatment - drug-resistant tuberculosis treatment. (2022). World Health Organisation, Key updates to the treatment of drug-resistant tuberculosis - rapid communication. (2024). Nehru, V.J. , et al. Risk assessment and transmission of fluoroquinolone resistance in drug-resistant pulmonary tuberculosis: a retrospective genomic epidemiology study. Scientific Reports 14 , 19719 (2024). McKee, E.E., Ferguson, M., Bentley, A.T. & Marks, T.A. Inhibition of mammalian mitochondrial protein synthesis by oxazolidinones. Antimicrob Agents Chemother 50 , 2042-2049 (2006). Stop TB Partnership, Clinical Pipeline. (2024). de Jager, V.R. , et al. Telacebec (Q203), a New Antituberculosis Agent. N Engl J Med 382 , 1280-1281 (2020). Chandrasekera, N.S. , et al. Improved Phenoxyalkylbenzimidazoles with Activity against Mycobacterium tuberculosis Appear to Target QcrB. ACS Infectious Diseases 3 , 898-916 (2017). Pethe, K. , et al. Discovery of Q203, a potent clinical candidate for the treatment of tuberculosis. Nature Medicine 19 , 1157-1160 (2013). Wani, M.A. & Dhaked, D.K. Targeting the cytochrome bc(1) complex for drug development in M. tuberculosis: review. Mol Divers 26 , 2949-2965 (2022). Nyang’wa, B.-T. , et al. A 24-Week, All-Oral Regimen for Rifampin-Resistant Tuberculosis. New England Journal of Medicine 387 , 2331-2343 (2022). Eimer, J. , et al. Association Between Increased Linezolid Plasma Concentrations and the Development of Severe Toxicity in Multidrug-Resistant Tuberculosis Treatment. Clin Infect Dis 76 , e947-e956 (2023). Vengurlekar, D. , et al. Linezolid resistance in patients with drug-resistant TB. Int J Tuberc Lung Dis 27 , 567-569 (2023). Wasserman, S. , et al. Linezolid toxicity in patients with drug-resistant tuberculosis: a prospective cohort study. J Antimicrob Chemother 77 , 1146-1154 (2022). Sotgiu, G., Centis, R., D'Ambrosio, L. & Migliori, G.B. Tuberculosis treatment and drug regimens. Cold Spring Harb Perspect Med 5 , a017822 (2015). Paton, N.I. , et al. Treatment Strategy for Rifampin-Susceptible Tuberculosis. New England Journal of Medicine 388 , 873-887 (2023). Komm, O.D. , et al. Contribution of telacebec to novel drug regimens in a murine tuberculosis model. bioRxiv , 2024.2006.2027.601059 (2024). Li, S.Y. , et al. Evaluation of moxifloxacin-containing regimens in pathologically distinct murine tuberculosis models. Antimicrob Agents Chemother 59 , 4026-4030 (2015). Kort, F. , et al. Fully weekly antituberculosis regimen: a proof-of-concept study. Eur Respir J 56 (2020). Akester, J.N. , et al. Synthesis, Structure-Activity Relationship, and Mechanistic Studies of Aminoquinazolinones Displaying Antimycobacterial Activity. ACS Infect Dis 6 , 1951-1964 (2020). Ray, P.C. , et al. Spirocycle MmpL3 Inhibitors with Improved hERG and Cytotoxicity Profiles as Inhibitors of Mycobacterium tuberculosis Growth. ACS Omega 6 , 2284-2311 (2021). Lamprecht, D.A., et al . Targeting de novo purine biosynthesis for tuberculosis treatment. Pre-print https://www.researchsquare.com/article/rs-4913610/v1 (2024). Additional Declarations Yes there is potential Competing Interest. JG, CV and DAL have been named inventors in a patent application for JNJ-2901 and JNJ-4052 compounds. CAP, CV, JG, MC, JE, NL, BS, JMB, VC, LBallell, BB, AK, ASP and DAL were/are all full-time employees of Janssen, a Johnson & Johnson company, and/or potential stockholders of Johnson & Johnson. The other authors declare no competing interests Supplementary Files Insightsintotheuseofcytochromebc1inhibitorsforfuturetherapeuticstrategiesfortuberculosissupplementary.docx NMEDBC136846epc.pdf Editorial Policy Checklist NMEDBC136846rs.pdf Reporting Summary Onlinemethods.docx Cite Share Download PDF Status: Published Journal Publication published 22 Oct, 2025 Read the published version in Nature Communications → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5331796","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Brief Communication","associatedPublications":[],"authors":[{"id":371900537,"identity":"a9dca9cc-b234-43d6-bb42-e6d2ca39b682","order_by":0,"name":"Clara Aguilar 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CO","correspondingAuthor":false,"prefix":"","firstName":"Gregory","middleName":"","lastName":"Robertson","suffix":""},{"id":371900565,"identity":"16b15940-1956-44d2-b9be-f6842bd415d4","order_by":26,"name":"Nicolas Veziris","email":"","orcid":"","institution":"Sorbonne Université","correspondingAuthor":false,"prefix":"","firstName":"Nicolas","middleName":"","lastName":"Veziris","suffix":""},{"id":371900566,"identity":"26cd1fdb-65da-4f14-8330-a30707969e51","order_by":27,"name":"Anna Upton","email":"","orcid":"","institution":"Evotec","correspondingAuthor":false,"prefix":"","firstName":"Anna","middleName":"","lastName":"Upton","suffix":""},{"id":371900567,"identity":"d590c58d-7cb7-45b7-b0c3-893a24db1fa6","order_by":28,"name":"Eric Nuermberger","email":"","orcid":"https://orcid.org/0000-0003-1440-9889","institution":"Johns Hopkins University School of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Eric","middleName":"","lastName":"Nuermberger","suffix":""},{"id":371900568,"identity":"c02e90fd-4b7e-44ba-bad1-d9a8e97840c1","order_by":29,"name":"Vivian Cox","email":"","orcid":"","institution":"Janssen Pharmaceutica","correspondingAuthor":false,"prefix":"","firstName":"Vivian","middleName":"","lastName":"Cox","suffix":""},{"id":371900569,"identity":"fcb57073-834e-4873-b0c6-69884cf2f05b","order_by":30,"name":"Lluis Ballell","email":"","orcid":"","institution":"Janssen Pharmaceutica","correspondingAuthor":false,"prefix":"","firstName":"Lluis","middleName":"","lastName":"Ballell","suffix":""},{"id":371900570,"identity":"de880bf9-7a58-4595-9bc5-94297c85b030","order_by":31,"name":"Benny Baeten","email":"","orcid":"","institution":"Janssen Pharmaceutica","correspondingAuthor":false,"prefix":"","firstName":"Benny","middleName":"","lastName":"Baeten","suffix":""},{"id":371900571,"identity":"01c68e94-8636-406c-a66b-63e386e7e114","order_by":32,"name":"Anil Koul","email":"","orcid":"","institution":"Janssen Research and Development, Johnson and Johnson","correspondingAuthor":false,"prefix":"","firstName":"Anil","middleName":"","lastName":"Koul","suffix":""},{"id":371900572,"identity":"893a64fa-a703-44f3-9734-e83ff1e3abd2","order_by":33,"name":"Alexander Pym","email":"","orcid":"","institution":"Janssen Pharmaceutica","correspondingAuthor":false,"prefix":"","firstName":"Alexander","middleName":"","lastName":"Pym","suffix":""},{"id":371900573,"identity":"ba0d9a9f-767f-4c09-9b63-fb5b2d57ee70","order_by":34,"name":"Richard Wall","email":"","orcid":"","institution":"London School of Hygiene and Tropical Medicine","correspondingAuthor":false,"prefix":"","firstName":"Richard","middleName":"","lastName":"Wall","suffix":""},{"id":371900574,"identity":"690343e9-4e1f-424d-9a45-403d4e040838","order_by":35,"name":"Dirk Lamprecht","email":"","orcid":"","institution":"Janssen Pharmaceutica","correspondingAuthor":false,"prefix":"","firstName":"Dirk","middleName":"","lastName":"Lamprecht","suffix":""}],"badges":[],"createdAt":"2024-10-25 10:51:06","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5331796/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5331796/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41467-025-64427-6","type":"published","date":"2025-10-22T04:00:00+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":67949030,"identity":"564ffb1f-92ea-482d-b6cf-a2eed2089c40","added_by":"auto","created_at":"2024-10-31 15:01:29","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":183066,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eInvestigating alternative MDR-TB treatment regimens based on inclusion of a cytochrome \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003ebc\u003c/strong\u003e\u003c/em\u003e\u003csub\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e inhibitor in relapsing mouse models of TB \u003c/strong\u003e– (A) Schematic of the studies presented in this project. (B-D) Lung bacterial burden, proportions of mice with positive cultures at end of treatment and relapse in \u003cem\u003eM. tuberculosis\u003c/em\u003e-infected mice from Studies A, B and D. CFU data is shown for week 8 (panels B-C) and week 12 (panel D). Details of treatment doses can be found in \u003cstrong\u003eSupplementary Tables S4 and S11\u003c/strong\u003e. Bedaquiline: B; pretomanid: Pa; clofazimine: C; linezolid: L; moxifoxacin: M; JNJ-2901: J. SoT: Start of treatment. *: relapse rate; 12 or 16 weeks after treatment cessation (\u003cem\u003e+12\u003c/em\u003e or \u003cem\u003e16\u003c/em\u003e wks). Relapse rate (n/N).\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5331796/v1/874a554b66d3c9f14f60e00a.png"},{"id":67949032,"identity":"c8126c17-80d4-4b10-a73b-a2363e9ec983","added_by":"auto","created_at":"2024-10-31 15:01:29","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":135796,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eInvestigating alternative DS-TB treatment regimens based on inclusion of a cytochrome \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003ebc\u003c/strong\u003e\u003c/em\u003e\u003csub\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e inhibitor and bactericidal activity using a clinical isolate\u003c/strong\u003e\u003cem\u003e\u003cstrong\u003e \u003c/strong\u003e\u003c/em\u003e– (A) Lung bacterial burden and relapse in \u003cem\u003eM. tuberculosis\u003c/em\u003e-infected mice from Study E. Details of treatment doses can be found in \u003cstrong\u003eSupplementary Table S12. \u003c/strong\u003eLimit of detection (dotted line) was 0.4 log\u003csub\u003e10\u003c/sub\u003e CFU lung\u003csup\u003e-1\u003c/sup\u003e. Bedaquiline: B; clofazimine: C; rifampicin: R; ethambutol: E; isoniazid: H; telacebec: T; pyrazinamide: Z. (B) Distribution of MIC\u003csub\u003e90\u003c/sub\u003e (concentration achieving 90% inhibition) values for a diverse selection of clinical isolates (black) compared with the lab-adapted WT H37Rv (cyan) for JNJ-4052 and bedaquiline (BDQ) (\u003cstrong\u003eSupplementary Table S15\u003c/strong\u003e). Clinical isolate N1283 (orange) is indicated. n =2 technical replicates.\u0026nbsp; Impact of (C) JNJ-4052, (D) JNJ-2901 and (E) telecebec on CFU counts in WT H37Rv compared to N1283 clinical isolate. n = ≥2 biological replicates. (F) \u003cem\u003eIn vivo\u003c/em\u003e efficacy (Study F) of JNJ-4052 (50 mg kg\u003csup\u003e-1\u003c/sup\u003e; PO) in H37Rv and N1283 after 2 weeks of treatment. SoT: Start of treatment, 7 days after inoculum with 300 CFU. n = 3 mice. ** = p\u0026lt;0.01.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-5331796/v1/48127ea6c6f756e91cff3e0e.png"},{"id":94169311,"identity":"39e19b75-680a-465b-b295-0df4a1d34f57","added_by":"auto","created_at":"2025-10-23 07:07:05","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1208399,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5331796/v1/ce1c2fbb-1c1f-4248-85d6-a48468ed9753.pdf"},{"id":67949035,"identity":"8f3f691b-a72f-4016-8d00-b62374fc39ef","added_by":"auto","created_at":"2024-10-31 15:01:30","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":2467151,"visible":true,"origin":"","legend":"","description":"","filename":"Insightsintotheuseofcytochromebc1inhibitorsforfuturetherapeuticstrategiesfortuberculosissupplementary.docx","url":"https://assets-eu.researchsquare.com/files/rs-5331796/v1/045aa797e3191eab648f3236.docx"},{"id":67949034,"identity":"df9f4e53-7cff-4c7d-b86c-1f03bf8d845c","added_by":"auto","created_at":"2024-10-31 15:01:29","extension":"pdf","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":1549475,"visible":true,"origin":"","legend":"Editorial Policy Checklist","description":"","filename":"NMEDBC136846epc.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5331796/v1/1f15afef80e4398c9fb41b66.pdf"},{"id":67949648,"identity":"b805b498-53ae-48d6-bddd-0c4d05ae07c5","added_by":"auto","created_at":"2024-10-31 15:09:30","extension":"pdf","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":2075793,"visible":true,"origin":"","legend":"Reporting Summary","description":"","filename":"NMEDBC136846rs.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5331796/v1/edf20985be44a6cb91bd3f8d.pdf"},{"id":67949033,"identity":"4b3ccd63-eaa3-436c-8e9b-4679661e008d","added_by":"auto","created_at":"2024-10-31 15:01:29","extension":"docx","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":181047,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinemethods.docx","url":"https://assets-eu.researchsquare.com/files/rs-5331796/v1/efbf5392c0efe4c3df2d1c76.docx"}],"financialInterests":"\u003cb\u003eYes\u003c/b\u003e there is potential Competing Interest.\nJG, CV and DAL have been named inventors in a patent application for JNJ-2901 and JNJ-4052 compounds. CAP, CV, JG, MC, JE, NL, BS, JMB, VC, LBallell, BB, AK, ASP and DAL were/are all full-time employees of Janssen, a Johnson \u0026 Johnson company, and/or potential stockholders of Johnson \u0026 Johnson. The other authors declare no competing interests","formattedTitle":"Insights into the use of cytochrome bc1 inhibitors for future therapeutic strategies for tuberculosis","fulltext":[{"header":"Full Text","content":"\u003cp\u003eThe global response to the tuberculosis (TB) epidemic has been exacerbated by the emergence of multidrug-resistant TB (MDR-TB). Combination treatment for TB is essential to prevent drug resistance, ensure complete eradication of the bacteria, and improve treatment effectiveness; however, current regimens still require many months of treatment.\u0026nbsp;The World Health Organisation\u0026rsquo;s consolidated guidelines include new recommendations for treatment shortening\u003csup\u003e1,2\u003c/sup\u003e. These recommendations suggest two six-month regimen options (compared to the previous 9 to 18-month duration): BPaLM (bedaquiline, pretomanid, linezolid and moxifloxacin) for ages 14 years and older, and BDLLfxC (bedaquiline, delamanid, linezolid, levofloxacin and clofazimine) for children, adolescents, adults and pregnant women. The central role that fluoroquinolones (FQ) and linezolid play in those regimens pose serious limitations due to drug resistance and toxicity, respectively. Moxifloxacin (M) or levofloxacin (Lfx) must be excluded in cases of fluoroquinolone resistance\u003csup\u003e3\u003c/sup\u003e, modifying the regimens to BPaL and BDLC, respectively. Furthermore, the use of linezolid in MDR-TB treatment is often associated with adverse events, such as myelosuppression and peripheral neuropathy, which may negatively impact patient adherence and require regimen modification\u003csup\u003e4\u003c/sup\u003e. While\u0026nbsp;MDR-TB treatment options are diversifying and improving\u003csup\u003e5\u003c/sup\u003e, emerging drug resistance adds additional concerns, underscoring the urgent need to discover compounds with novel modes of action (MoA) and develop novel therapeutic approaches. The discovery of Q203 (telacebec, T; \u003cstrong\u003eSupplementary Figure S1\u003c/strong\u003e) and its successful Phase 2A Early Bactericidal Activity (EBA) trial has highlighted the inhibition of the cytochrome\u0026nbsp;\u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003ecomplex of\u003cem\u003e\u0026nbsp;Mycobacterium tuberculosis\u003c/em\u003e as a promising new molecular target\u003csup\u003e6-8\u003c/sup\u003e. The cytochrome \u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e complex is a crucial part of the electron transport chain, essential for ATP production, potentially making an inhibitor of cytochrome \u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e a good partner drug for other inhibitors of oxidative phosphorylation such as bedaquiline. Despite this potential, currently, there is limited demonstration of the specific role cytochrome\u0026nbsp;\u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitors could play in future TB treatment regimens\u003csup\u003e9\u003c/sup\u003e. Here, using relapsing mouse models, we\u0026nbsp;assessed the contribution of a validated cytochrome\u0026nbsp;\u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitor tool compound (JNJ-2901, J) in different treatment regimen strategies with special focus on combinations devoid of FQ-resistance liability or linezolid-associated toxicity (\u003cstrong\u003eFigure 1A\u003c/strong\u003e,\u0026nbsp;\u003cstrong\u003eSupplementary\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;Figure S1-2,\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eSupplementary\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;Table S1-3\u003c/strong\u003e).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn the TB-PRACTECAL trial, the BPaLC (bedaquiline, pretomanid, linezolid and clofazimine)\u0026nbsp;regimen resulted in a higher proportion of MDR-TB patients with favourable outcomes (81%) compared to BPaL (77%) and standard of care (SoC; 52%), primarily due to early treatment discontinuation from adverse events in the SoC group\u003csup\u003e10\u003c/sup\u003e. Given the adverse effects associated with the use of linezolid in the treatment of MDR-TB, there is growing interest in identifying alternative partner drugs\u003csup\u003e11-13\u003c/sup\u003e.Here, using a mouse model, we show that a regimen including a cytochrome \u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitor could serve as a promising alternative (\u003cstrong\u003eFigure 1B-C\u003c/strong\u003e; \u003cstrong\u003eSupplementary\u003c/strong\u003e \u003cstrong\u003eTable S4-7\u003c/strong\u003e;Studies A and B).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAlthough BPaL, the regimen recommended for fluoroquinolone-resistant MDR-TB, led to a greater decrease in colony forming units (CFU) after 8 weeks compared to BPaJ, comparable relapse rates (measured after 3 months post treatment) were observed after 8 weeks (86.6%-100% for BPaL, 100% for BPaJ) and 12 weeks of treatment (26.6% for both regimens). Replacing linezolid with clofazimine resulted in a similar decrease in CFU after 8 weeks but led to fewer relapses post-treatment (86.6%-100% for BPaL, 26.6-66.6% for BPaC). BPaCJ demonstrated the best bactericidal effect, achieving an additional 1 log\u003csub\u003e10\u003c/sub\u003e decrease in CFU compared to BPaC after 8 weeks, translating to a 33% relapse rate. No relapses occurred after 12 weeks of treatment with either BPaC or BPaCJ,\u0026nbsp;highlighting the potential for treatment shortening compared to the BPaL SoC (\u003cstrong\u003eFigure 1B-C; Supplementary Table S4-7\u003c/strong\u003e). Interestingly, addition of JNJ-2901 to a moxifloxacin-containing regimen (BPaMJ) did not lead to a further decrease in bacterial burden or in relapse rate compared with BPaM (\u003cstrong\u003eFigure 1B; Supplementary Table S4-7\u003c/strong\u003e). Our findings demonstrate that combining a cytochrome \u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitor with BPaC increases the sterilising activity compared to BPaC alone, suggesting that cytochrome \u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitors could play an important role in future MDR-TB regimens. In an additional study (Study C), JNJ-2901\u0026nbsp;reduced the relapse rate when combined with the BPaL regimen, despite an inability to rescue mice when administered as a monotherapy in an intravenous model using the H37Rv reference strain (\u003cstrong\u003eSupplementary Figure S3\u003c/strong\u003e). There was a trend towards improvement of both the bacterial burden (BPaLJ: 0.95 \u0026plusmn; 1.1 vs BPaL: 2.06 \u0026plusmn; 1.3 log\u003csub\u003e10\u003c/sub\u003e CFU lung\u003csup\u003e-1\u003c/sup\u003e, \u003cem\u003ep\u003c/em\u003e=0.04) and a quantifiable improvement in relapse rates, that failed to reach statistical significance within the limitations of this trial design (50% vs 89%, \u003cem\u003ep\u003c/em\u003e\u0026gt;0.05), while BPaLJ was comparable to BPaLM and BPaMZ (\u003cstrong\u003eSupplementary\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;Table S8-10\u003c/strong\u003e). This suggests that BPaLJ could be considered as a potential treatment regimen irrespective of fluoroquinolone susceptibility.\u003c/p\u003e\n\u003cp\u003eIn a further study, an alternative dosing strategy was used where mice were treated with BPaL for 8 weeks during an initial phase, followed by an additional 8 weeks of either BPa, BJ, B or no treatment in a continuation phase. The rationale for this study design was to reduce the time and overall amount of drug required to reach bacterial sterility. Bacterial burdens in lungs were assessed after 8, 12 and 16 weeks, and relapse rates were measured after 16 weeks of treatment plus 16 weeks following treatment cessation (\u003cstrong\u003eFigure 1D;\u003c/strong\u003e \u003cstrong\u003eSupplementary Table S11\u003c/strong\u003e; Study D). Both the BPaL/BPa and BPaL/BJ regimens trended towards lower relapse rates compared to BPaL without continuation treatment, although this was not statistically significant (\u003cem\u003ep\u003c/em\u003e-value=0.09). No colonies were detected after 12 weeks of treatment with BPaL/BJ, whereas with BPaL/B, colonies were detected from 3/5 mice at the end of treatment. These results suggest that inclusion of a cytochrome \u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitor could enhance regimen effectiveness during the continuation phase of treatment with fewer drugs and a reduced overall drug burden. Effective regimens require drugs with both bactericidal and sterilising activities to rapidly reduce bacterial loads and kill drug-tolerant bacilli. Drugs in the continuation phase must target drug-tolerant bacteria that survive the initial intensive phase\u003csup\u003e14\u003c/sup\u003e. A two-phase regimen, with an initial phase of drugs that rapidly reduce bacterial burdens, followed by sterilising drugs in a continuation phase, is a proven strategy for improving treatment outcomes for patients. The inclusion of a cytochrome \u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitor in the continuation phase of the BPaL/BJ regimen demonstrated a sterilising effect similar to that of the BPaL/BPa regimen, suggesting that a cytochrome \u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitor could serve as an effective alternative to pretomanid (Pa).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eNext, we focused on an ultra-short treatment strategy for drug sensitive-TB (DS-TB) based on drugs targeting the respiratory pathway. For this purpose, we assessed the efficacy of regimens containing telacebec alongside other drugs targeting the respiratory pathway, compared to the current DS-TB SoC; isoniazid, rifampicin, pyrazinamide, and ethambutol (HRZE; Study E). BCZ, CZT and BCZT regimens all demonstrated superior efficacy over HRZE after 8 weeks of treatment in reducing lung CFU burdens (\u003cstrong\u003eFigure 2A, Supplementary Tables S12-14\u003c/strong\u003e; Study E). Both BCZ and BCZT regimens achieved 0% relapse rates 12 weeks after 6- and 8-weeks of treatment, whereas CZT required at least 12 weeks of treatment to achieve 0% relapse. One of the mice treated with HRZE remained culture positive even after 20 weeks of treatment. The benefit of adding telacebec to BCZ is highlighted by the relapse rates after 4 weeks treatment: BCZ (60%) vs. BCZT (36%), underscoring the treatment-shortening potential of cytochrome\u0026nbsp;\u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitors in combination with other drugs targeting the electron transport chain. Based on the TRUNCATE-TB trial strategy, a 2-month BZ-containing regimen could be as effective as the current 6-month standard (HRZE)\u003csup\u003e15\u003c/sup\u003e.\u0026nbsp;Adding telacebec to the CZ core regimen reduced bacterial load by 2.2 log\u003csub\u003e10\u003c/sub\u003e CFU in this model and, including telacebec in CZ or BCZ regimens significantly shortened treatment compared to HRZE. These findings provide strong evidence that incorporating a cytochrome\u0026nbsp;\u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitor into new treatment regimens offers substantial benefits which should be further investigated.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWe found that the impact of cytochrome \u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitors may be underrepresented depending on the \u003cem\u003eM. tuberculosis\u003c/em\u003e strain selected for investigation. Here, using another cytochrome \u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitor, JNJ-4052, we demonstrate that a diverse range of clinical isolates from infected patients exhibited increased susceptibility to cytochrome \u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitors in both minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays when compared to the lab-adapted H37Rv strain(\u003cstrong\u003eFigures 2B-E; Supplementary Table S15\u003c/strong\u003e). This heightened susceptibility translated into increased \u003cem\u003ein vivo\u003c/em\u003e efficacy in an acute mouse model, where a statistically significant CFU reduction (1.6 log\u003csub\u003e10\u003c/sub\u003e reduction; \u003cem\u003ep\u003c/em\u003e\u0026lt;0.01) was observed following cytochrome \u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitor (JNJ-4052) treatment in mice inoculated with a clinical isolate (\u003cstrong\u003eFigure 2F; Supplementary Tables S1-S3\u003c/strong\u003e; Study F). Further work is needed to determine whether the routine use of clinical isolates should be incorporated into regimen design studies. Indeed, similar findings have recently been reported\u003csup\u003e16\u003c/sup\u003e, showing that the clinical isolate HN878 is more susceptible to cytochrome \u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitors, with a notable contribution when added to BPaC, resulting in a 2-log reduction in lung bacterial burden between BPaC and BPaCT, after 4 weeks of treatment. These results further emphasise the relevance of clinical isolates for evaluating the \u003cem\u003ein vivo\u003c/em\u003e efficacy of new compounds.\u003c/p\u003e\n\u003cp\u003eTogether, our findings suggest that cytochrome \u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitors could play a crucial role in future TB treatment regimens. Specifically, cytochrome \u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitors may serve as effective replacements for linezolid in SoC regimens for MDR- and fluoroquinolone-resistant MDR-TB. As this represents a novel MoA, it could also help raise the barrier to resistance development to other components of the regimen and could be use for treatment of DS-TB. Our experiments containing a treatment phase followed by a continuation phase may also benefit future formulation strategies such as long acting injectables (LAI) providing an alternative strategy to improve treatment outcomes. Finally, drug repurposing has proven to be an effective strategy for accelerating the discovery of new treatments; linezolid, for example, was originally developed for vancomycin-resistant enterococcal infections. Our data highlight the potential of both clofazimine- and cytochrome \u003cem\u003ebc\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e inhibitor-containing regimens to significantly shorten treatment durations for both DS- and DR-TB.\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors would like to thank: Amit Kaushik for technical support at\u0026nbsp;Johns Hopkins University; AT Henze and PM Petrar for medical writing support at Janssen Pharmaceutica; Annelies Wouter and Lieve Lammens for toxicology input at Janssen Pharmaceutica; Nadia Neto for her feedback on WGS at Janssen Pharmaceutica; Gregory Bancroft for his intellectual input at the London School of Hygiene \u0026amp; Tropical Medicine; and Courtney I. Hastings at Colorado State University for technical support.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCAP, DAL, AJL, SS, GTR, NL, AU, NV, ELN, NCA AA, AC BB, LB, HP, JD and ASP were involved in the conception or the design of the study. JG and JMB designed and synthesised the compounds. AK, CV, DAL, BB, ASP and LBallell supervised the overall research programme. CAP, SS, ELN, AC, NCA, TCM, SW, NV, NW, HP, JD, AH, BS, \u0026nbsp;LBrock, GG and GR participated in the collection or generation of the studies data. SS, EN, AC, TCM, SW, HP, JD, AH, VG and GTR performed the studies. CAP, SS, ELN, JE, TGC and GR contributed to the study with materials/analysis tools. CAP, AJL, NV, SW, GTR, SS, MC, ELN, NCA, LBallell, JD, HP, VC, BS, RJW and DAL were involved in the analysis or interpretation of the data. CAP, RJW and DAL wrote the manuscript. All authors reviewed and commented drafts of the manuscript for intellectual content and gave final approval to submit for publication. All authors attest they meet the ICMJE criteria for authorship.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data generated or analysed during this study are included in this published article (and its supplementary information files).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest statement\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eJG, CV and DAL have been named inventors in a patent application for JNJ-2901 and JNJ-4052 compounds. CAP, CV, JG, MC, JE, NL, BS, JMB, VC, LBallell, BB, AK, ASP and DAL were/are all full-time employees of Janssen, a Johnson \u0026amp; Johnson company, and/or potential stockholders of Johnson \u0026amp; Johnson. The other authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by Janssen Pharmaceutica NV, including all costs associated with the development and publishing of the manuscript. The work at the London School of Hygiene \u0026amp; Tropical Medicine was supported by funding from Janssen Pharmaceutica. This project has received funding from the Innovative Medicines Initiative 2 Joint Undertaking under grant agreement No 853903 (RespiriTB). This Joint Undertaking receives support from the European Union\u0026rsquo;s Horizon 2020 research and innovation programme and EFPIA.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eWorld Health Organisation, WHO consolidated guidelines on tuberculosis. Module 4: treatment - drug-resistant tuberculosis treatment. 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Targeting de novo purine biosynthesis for tuberculosis treatment. \u003cem\u003ePre-print \u003c/em\u003ehttps://www.researchsquare.com/article/rs-4913610/v1 (2024).\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"nature-portfolio","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Nature Portfolio","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"ejp","reportingPortfolio":"","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-5331796/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5331796/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Recent efforts to improve tuberculosis (TB) treatment options have focused on developing molecules with novel mechanisms of action and identifying optimal treatment regimens. Inhibition of Mycobacterium tuberculosis cytochrome bc1 oxidase has emerged as a promising therapeutic target that could potentially contribute to improved TB combination regimens. Using a relapsing mouse model, we demonstrate that cytochrome bc1 inhibitors could serve as effective partner drugs, enhancing regimen sterilisation. We propose several novel regimen strategies for both multidrug-resistant TB (MDR-TB) and drug-sensitive TB (DS-TB), where cytochrome bc1 inhibitors contribute to sterilisation and treatment shortening. Additionally, we show that clinical isolates exhibit heightened susceptibility to cytochrome bc1 inhibitors compared to laboratory-adapted strains, further supporting their translational potential. These findings suggest that cytochrome bc1 inhibitors have significant potential to improve TB treatment outcomes and highlight the need for further studies to evaluate their clinical contribution to novel treatment regimens.","manuscriptTitle":"Insights into the use of cytochrome bc1 inhibitors for future therapeutic strategies for tuberculosis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-10-31 15:01:24","doi":"10.21203/rs.3.rs-5331796/v1","editorialEvents":[],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"nature-communications","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"NCOMMS","sideBox":"Learn more about [Nature Communications](http://www.nature.com/ncomms/)","snPcode":"","submissionUrl":"https://mts-ncomms.nature.com/","title":"Nature Communications","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature Communications","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"2346ca40-7b92-4aef-a599-6a7c455bddec","owner":[],"postedDate":"October 31st, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":39580086,"name":"Health sciences/Diseases/Infectious diseases/Tuberculosis"},{"id":39580087,"name":"Biological sciences/Microbiology/Antimicrobials/Antibiotics"},{"id":39580088,"name":"Biological sciences/Microbiology/Antimicrobials/Antimicrobial resistance"}],"tags":[],"updatedAt":"2025-10-23T07:06:57+00:00","versionOfRecord":{"articleIdentity":"rs-5331796","link":"https://doi.org/10.1038/s41467-025-64427-6","journal":{"identity":"nature-communications","isVorOnly":false,"title":"Nature Communications"},"publishedOn":"2025-10-22 04:00:00","publishedOnDateReadable":"October 22nd, 2025"},"versionCreatedAt":"2024-10-31 15:01:24","video":"","vorDoi":"10.1038/s41467-025-64427-6","vorDoiUrl":"https://doi.org/10.1038/s41467-025-64427-6","workflowStages":[]},"version":"v1","identity":"rs-5331796","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5331796","identity":"rs-5331796","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}