Oral Presentation 25th International Pathogenic Neisseria Conference 2026

Development of an ethically-approved first-in-human oropharyngeal gonorrhoea controlled human infection model (#067)

Eloise Williams 1 2 3 , Georgina L Pollock 1 4 , Tim Crocker-Buque 1 4 , Dana de Krester 1 , Euzebiusz Jamrozik 1 5 , Deborah Williamson 1 6 , James McCarthy 1 4 7
  1. Department of Infectious Diseases, University of Melbourne at the Peter Doherty Institute of Infection and Immunity, Melbourne, Victoria, Australia
  2. Victorian Infectious Diseases Reference Laboratory, The Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
  3. Department of Infectious Diseases and Immunology, Austin Health, Melbourne, Victoria, Australia
  4. The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria , Australia
  5. Ethox and Pandemic Sciences Institute, University of Oxford, Oxford, Oxfordshire, United Kingdom
  6. School of Medicine, University of St Andrews, Fife, Scotland, United Kingdom
  7. Victorian Infectious Diseases Service, The Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia

Background

Gonorrhoea, a sexually transmissible infection caused by Neisseria gonorrhoeae, causes a significant global burden of disease. Management of gonorrhoea is threatened by increasing antimicrobial resistance (AMR). Oropharyngeal gonorrhoea is usually asymptomatic, plays an important role in development of AMR and is a high-risk site for treatment failure. As such, an oropharyngeal gonorrhoea controlled human infection model (CHIM) could serve as an important platform for early-stage assessment of gonorrhoea prevention and treatment strategies at the most challenging anatomical site.

 

Methods and analysis

This dose-escalation oropharyngeal gonorrhoea CHIM study will enrol 20-35 healthy adult volunteers aged 18 to 50 years who were assigned male at birth and only have sex with people assigned male at birth. The primary objectives are to determine i) the safety and tolerability of an oropharyngeal gonorrhoea CHIM; and, ii) the minimum infectious dose of novel N. gonorrhoeae challenge isolate AUSMDU00053933 required for 60-80% of participants to develop oropharyngeal N. gonorrhoeae infection. Secondary and exploratory endpoints include description of clinical, immunological, microbiological and pharmacometric responses. Participants will be monitored daily as outpatients during the five-day experimental infection phase. All participants will be treated with 1g intramuscular ceftriaxone and followed up for three months. Statistical analysis and dose escalation/de-escalation decisions will follow a model-based continual reassessment method in a Bayesian statistical framework. Protocol development was informed by feedback from community engagement. Ethical approval for commencement of the study was obtained through the Bellberry Limited human research ethics committee.

 

Conclusion

This oropharyngeal gonorrhoea CHIM has been designed in collaboration with stakeholders, including community, to optimise safety and acceptability. This first proof-of-principle study aims to demonstrate that this CHIM can be used as a platform to accelerate novel therapeutics and vaccines for gonorrhoea treatment and prevention. It will provide unprecedented microbiological, immunological and pharmacometric data about early oropharyngeal gonorrhoea infection. Progress on the ongoing trial will be reported at the meeting.