Unchaining diagnostic and therapeutic tools for syphilis in pregnancy, neurosyphilis and treatment failure

BREAKFREE-Sy

BREAKFREE-Sy is a five-year research project funded by the European Union’s Horizon Europe program under Grant Agreement No. 101171779. It aims to demonstrate that syphilis manifestations are linked to specific bacterial traits and host responses. We will identify biomarkers and repurpose antibiotics through two pioneering clinical trials targeting neurosyphilis and syphilis in pregnancy—both severe, neglected conditions needing alternatives to penicillin. Ultimately, the project will provide innovative diagnostic tools and potential vaccine antigens to reduce syphilis complications.

The project is led by the Research Unit for Infectious and Tropical Diseases at the Germans Trias i Pujol Research Institute, in collaboration with the University of Washington (UW), IrsiCaixa, and the Hospital for Skin Diseases, Chinese Academy of Medical Sciences. 

Why this research matters

For over 50 years, the tools for diagnosing, preventing, and treating syphilis have seen minimal progress, partly due to limitations in bacterial cultivation. Existing tools are largely based on research on early-stage syphilis and extrapolated to severe forms, leaving major unmet needs, including predictive markers for neurosyphilis and mother-to-child transmission, evidence-based treatments for these conditions, and tools to monitor treatment failure. This project aims to shift the paradigm by demonstrating that the diverse manifestations of syphilis are not random infections in different bodily compartments but are linked to specific bacterial traits and host responses that require tailored tools. Our goal is to discover manifestation-specific biomarkers, repurpose antibiotics for tailored treatments, and pioneer TPA isolation methods for treatment monitoring.

Leveraging a unique network of collaborators in areas with a high incidence of severe syphilis, we will examine how severe clinical manifestations relate to genomic variation in TPA strains and host humoral responses. A pan-proteomic array will identify markers linked to clinical phenotypes and potential new antigens as vaccine candidates. Building on our expertise in drug repurposing and randomized clinical trials, we will evaluate alternative antibiotics for neurosyphilis and syphilis in pregnancy. We will also pioneer the isolation of TPA from patient samples and antimicrobial resistance testing in treatment failures. These tools could help prevent neurological sequelae, stillbirth, congenital syphilis, and treatment failure, particularly in low- and middle-income countries where most complications occur.

 

Safety and Efficacy of Linezolid for Treating Neurosyphilis (NeuroTrep)

Neurosyphilis occurs when Treponema pallidum invades the central nervous system and can cause severe neurological, ocular and auditory complications. Current treatment requires a 14-day course of intravenous aqueous crystalline penicillin G because intramuscular benzathine penicillin does not achieve adequate concentrations in cerebrospinal fluid. This requires prolonged and intensive intravenous treatment, creating a substantial burden for patients and healthcare systems.

Linezolid combines potent anti-treponemal activity with good central nervous system penetration and oral administration, making it a promising candidate for a simpler treatment of neurosyphilis.

NeuroTrep aims to determine whether oral linezolid is non-inferior to standard intravenous penicillin for the treatment of neurosyphilis.

Implemented with the Hospital for Skin Diseases, Chinese Academy of Medical Sciences (China), NeuroTrep is a multicenter, randomized, open-label, two-arm non-inferiority clinical trial involving 120 participants with neurosyphilis. Participants will receive either oral linezolid (600 mg twice daily for 14 days) or standard intravenous aqueous crystalline penicillin G for 14 days and will be followed for 48 weeks. Clinical, cerebrospinal fluid and serological responses will be evaluated to determine treatment efficacy and safety.

The clinical trial is combined with translational studies designed to:

  • Characterize linezolid pharmacokinetics and its penetration into cerebrospinal fluid
  • Identify genomic traits of T. pallidum associated with specific neurosyphilis manifestations
  • Characterize T. pallidum antigens and host humoral responses
    associated with different clinical presentations
  • Isolate and characterize T. pallidum strains for genomic studies
 

Repurposing of antibiotics for syphilis in pregnancy (CELINE)

Syphilis during pregnancy can lead to severe adverse outcomes, including stillbirth, neonatal death and congenital syphilis. Benzathine penicillin G (BPG) remains the standard treatment, but its use presents important limitations, including penicillin allergy, the need for intramuscular administration and difficulties accessing treatment in some settings. Cefixime is an oral cephalosporin with demonstrated activity against Treponema pallidum and a favorable safety profile in pregnancy, making it a promising alternative treatment.

CELINE aims to determine whether oral cefixime can provide an effective and safe alternative to benzathine penicillin for treating syphilis during pregnancy, while preventing congenital syphilis.

Implemented together with the Institute of Dermatology, Chinese Academy of Medical Sciences & Peking Union Medical College (China), with the collaboration of the National Center for Women and Children’s Health (China), the London School of Hygiene & Tropical Medicine (UK), University College Dublin (Ireland) and the University of Texas (USA), CELINE is a Phase II, multicenter, open-label, randomized non-inferiority clinical trial involving 230 pregnant women with syphilis. Participants will receive either oral cefixime or standard BPG treatment and will be followed for up to 48 weeks after treatment, while infants will also be evaluated for congenital syphilis and other health outcomes.

Beyond the clinical trial, CELINE integrates translational research to:

  • Assess maternal and infant clinical and serological outcomes cerebrospinal fluid
  • Characterize cefixime pharmacokinetics during pregnancy
  • Investigate T. pallidum genomics and its association with treatment
    response and pregnancy outcomes
  • Characterize the maternal humoral response to T. pallidum antigens
  • Explore new approaches for diagnosing congenital syphilis, including
    neonatal TPA-IgM.
 

Publications

“Coming soon!”

Millat-Martínez, P; Katusele, M; Kasian, B; Omera, E; Jamea, E; Lorry, L (…); Baró, B.

Human and entomological determinants of malaria transmission in the Lihir Islands of Papua New Guinea: A cross-sectional study Journal Article

In: PLOS Neglected Tropical Diseases, vol. 19, iss. 1, 2025.

Abstract | Links | BibTeX

Handley, Becca; González-Beiras, Camila; Tchatchouang, Serges; Hugues, Kouadio Aboh; Basing, Laud Antony; Sylla, Aboubacar (…); Marks, Michael.

A loop-mediated isothermal amplification test for yaws: a multi-country diagnostic accuracy evaluation Journal Article

In: The Lancet Global Health, vol. 12, iss. 11, pp. e1891-e1898, 2024.

Abstract | Links | BibTeX

Tchatchouang, Serges; Basing, Laud Antony; Hugues, Kouadio Aboh; Handley, Becca; Gonzalez-Beiras, Camila; Amanor, Ivy (…); Marks, Michael.

An integrated active case detection and management of skin NTDs in yaws endemic health districts in Cameroon, Côte d'Ivoire and Ghana Journal Article

In: PLOS Neglected Tropical Diseases, vol. 18, iss. 10, 2024.

Abstract | Links | BibTeX

Medappa, Monica; Popisilova, Petra; John, Lucy N.; Gonzalez-Beiras, Camila; Vall-Mayans, Martí; Mitjà, Oriol; Smajs, David

Sequence typing of Haemophilus ducreyi isolated from patients in the Namatanai region of Papua New Guinea: Infections by Class I and Class II strain types differ in ulcer duration and resurgence of infection after azithromycin treatment Journal Article

In: PLOS Neglected Tropical Diseases, vol. 18, iss. 8, 2024.

Abstract | Links | BibTeX

González-Beiras, Camila; Adingra, Tano; Handley, Becca; Arhinful, Daniel; Tchatchouang, Serges; Houndji, Ahouansou (…); Marks, Michael.

Knowledge, attitudes and practices towards yaws in endemic areas of Ghana, Cameroon and Côte d'Ivoire Journal Article

In: PLOS Neglected Tropical Diseases, vol. 18, iss. 6, 2024.

Abstract | Links | BibTeX

Medappa, Monica; Popisilova, Petra; Madruga, María Paula; John, Lucy N.; Gonzalez-Beiras, Camila; Grillova, Linda (…); Smajs, David

Low genetic diversity of Treponema pallidum ssp. pertenue (TPE) isolated from patients' ulcers in Namatanai District of Papua New Guinea: Local human population is infected by three TPE genotypes Journal Article

In: PLOS Neglected Tropical Diseases, vol. 18, iss. 1, 2024.

Abstract | Links | BibTeX

Ndzomo, Philippe; Tchatchouang, Serges; Tabah, Ernest; Njamsshi, Theophilus; Tsanga, Mireille Victorine Noah; Bondi, Jules Alexis (…); Eyangoh, Sara

Prevalence and risk factors associated with Haemophilus ducreyi cutaneous ulcers in Cameroon Journal Article

In: PLOS Neglected Tropical Diseases, vol. 17, iss. 12, 2023.

Abstract | Links | BibTeX

Suñer, Clara; John, Lucy N; Houinei, Wendy; Ubals, Maria; Ouchi, Dan; Alemany, Andrea (…); González-Beiras, Camila

Rapid Serologic Test for Diagnosis of Yaws in Patients with Suspicious Skin Ulcers Journal Article

In: Emerging Infectious Diseases, vol. 29, iss. 8, 2023.

Abstract | Links | BibTeX

Alshehri, Abdullah; Chhonker, Yashpal S.; Bala, Veenu; Edi, Constant; Bjerum, Catherine M.; Koudou, Benjamin G (…); Murry, Daryl.

Population pharmacokinetic model of ivermectin in mass drug administration against lymphatic filariasis Journal Article

In: PLOS Neglected Tropical Diseases, vol. 17, no. 6, pp. 1-17, 2023.

Abstract | Links | BibTeX

John, Lucy N.; Beiras, Camila G.; Houinei, Wendy; Medappa, Monica; Sabok, Maria; Kolmau, Reman (…); Mitjà, Oriol.

Trial of Three Rounds of Mass Azithromycin Administration for Yaws Eradication Journal Article

In: New England Journal of Medicine, vol. 386, no. 1, pp. 47-56, 2022.

Abstract | Links | BibTeX

John, Lucy N.; Gonzalez-Beiras, Camila; Vall-Mayans, Marti; Kolmau, Reman; Houinei, Wendy; Wangi, James; Marks, Michael; Mitjà, Oriol

Safety of mass drug coadministration with ivermectin, diethylcarbamazine, albendazole, and azithromycin for the integrated treatment of neglected tropical diseases: a cluster randomized community trial Journal Article

In: The Lancet Regional Health – Western Pacific, 2021, ISSN: 2666-6065.

Abstract | Links | BibTeX

Grant, Jacob C; González-Beiras, Camila; Amick, Kristen M; Fortney, Kate R; Gangaiah, Dharanesh; Humphreys, Tricia L (…); Spinola, Stanley M.

Multiple Class I and Class II Haemophilus ducreyi Strains Cause Cutaneous Ulcers in Children on an Endemic Island Journal Article

In: Clinical Infectious Diseases, vol. 11, iss. 67, pp. 1768-1774, 2018.

Abstract | Links | BibTeX

Mitjà, Oriol; Godornes, Charmie; Houinei, Wendy; Kapa, August; Paru, Raymond; Abel, Haina (…); Lukehart, Sheila A.

Re-emergence of yaws after single mass azithromycin treatment followed by targeted treatment: a longitudinal study Journal Article

In: The Lancet, vol. 391, no. 10130, pp. 1599-1607, 2018, ISSN: 0140-6736.

Abstract | Links | BibTeX

Marks, Michael; Mitjà, Oriol; Bottomley, Christian; Kwakye, Cynthia; Houinei, Wendy; Bauri, Mathias (…); Wanaom, Augustine.

Comparative efficacy of low-dose versus standard-dose azithromycin for patients with yaws: a randomised non-inferiority trial in Ghana and Papua New Guinea Journal Article

In: The Lancet Global Health, vol. 6, no. 4, pp. e401-e410, 2018, ISSN: 2214-109X.

Abstract | Links | BibTeX

González-Beiras, Camila; Kapa, August; Vall-Mayans, Marti; Paru, Raymond; Gavilán, Sergi; Houinei, Wendy (…); Mitjà, Oriol.

Single-Dose Azithromycin for the Treatment of Haemophilus ducreyi Skin Ulcers in Papua New Guinea Journal Article

In: Clinical Infectious Diseases, vol. 65, iss. 12, pp. 2085–2090, 2017.

Abstract | Links | BibTeX

Mitjà, Oriol; González-Beiras, Camila; Godornes, Charmie; Kolmau, Reman; Houinei, Wendy; Abel, Haina (…); Bassat, Quique.

Effectiveness of single-dose azithromycin to treat latent yaws: a longitudinal comparative cohort study Journal Article

In: The Lancet Global Health, vol. 5, no. 12, pp. e1268-e1274, 2017, ISSN: 2214-109X.

Abstract | Links | BibTeX

Houinei, Wendy; Godornes, Charmie; Kapa, August; Knauf, Sascha; Mooring, Eric Q.; González-Beiras, Camila (…); Mitjà, Oriol.

Haemophilus ducreyi DNA is detectable on the skin of asymptomatic children, flies and fomites in villages of Papua New Guinea Journal Article

In: PLOS Neglected Tropical Diseases, vol. 11, no. 5, pp. 1-10, 2017.

Abstract | Links | BibTeX

González-Beiras, Camila; Marks, Michael; Chen, Cheng; Roberts, Sally; Mitjà, Oriol

Epidemiology of Haemophilus ducreyi Infections Journal Article

In: Emerging Infectious Diseases, vol. 22, no. 1, pp. 1-8, 2016.

Abstract | Links | BibTeX

Mitjà, Oriol; Houinei, Wendy; Moses, Penias; Kapa, August; Paru, Raymond; Hays, Russell (…); Bassat, Quique.

Mass Treatment with Single-Dose Azithromycin for Yaws Journal Article

In: New England Journal of Medicine, vol. 372, no. 8, pp. 703-710, 2015.

Abstract | Links | BibTeX

Marks, Michael; Mitjà, Oriol; Vestergaard, Lasse S.; Pillay, Allan; Knauf, Sascha; Chen, Cheng-Yen (…); Asiedu, Kingsley B.

Challenges and key research questions for yaws eradication Journal Article

In: The Lancet Infectious Diseases, vol. 15, no. 10, pp. 1220-1225, 2015, ISSN: 1473-3099.

Abstract | Links | BibTeX

Mitjà, Oriol; Marks, Michael; Konan, Diby J. P.; Ayelo, Gilbert; Gonzalez-Beiras, Camila; Boua, Bernard (…); Asiedu, Kingsley B.

Global epidemiology of yaws: a systematic review Journal Article

In: The Lancet Global Health, vol. 3, no. 6, pp. e324-e331, 2015, ISSN: 2214-109X.

Abstract | Links | BibTeX

Mitjà, Oriol; Lukehart, Sheila A.; Pokowas, Gideon; Moses, Penias; Kapa, August; Godornes, Charmie (…); Bassat, Quique.

Haemophilus ducreyi as a cause of skin ulcers in children from a yaws-endemic area of Papua New Guinea: a prospective cohort study Journal Article

In: The Lancet Global Health, vol. 2, no. 4, pp. e235-e241, 2014, ISSN: 2214-109X.

Abstract | Links | BibTeX

Ayove, Telek; Houniei, Wendy; Wangnapi, Regina; Bieb, Sibauk V.; Kazadi, Walter; Luke, Lisol-Nirau (…); Mitjà, Oriol.

Sensitivity and specificity of a rapid point-of-care test for active yaws: a comparative study Journal Article

In: The Lancet Global Health, vol. 2, no. 7, pp. e415-e421, 2014, ISSN: 2214-109X.

Abstract | Links | BibTeX

Mitjà, Oriol; Asiedu, Kingsley; Mabey, David

Yaws Journal Article

In: The Lancet, vol. 381, no. 9868, pp. 763-773, 2013, ISSN: 0140-6736.

Abstract | Links | BibTeX

Mitjà, Oriol; Hays, Russell; Ipai, Anthony; Penias, Moses; Paru, Raymond; Fagaho, David; Lazzari, Elisa; Bassat, Quique

Single-dose azithromycin versus benzathine benzylpenicillin for treatment of yaws in children in Papua New Guinea: an open-label, non-inferiority, randomised trial Journal Article

In: The Lancet, vol. 379, no. 9813, pp. 342-347, 2012, ISSN: 0140-6736.

Abstract | Links | BibTeX