Streptococcus Pyogenes PharyngitisEarly Phase 1CHIVAS-M1NCT06992141
A Strep Throat Controlled Human Infection Trial in Healthy Adults
A Early Phase 1 study testing Streptococcus pyogenes M1UK strain MCRI0102 in people with Streptococcus Pyogenes Pharyngitis and Streptococcus Infection, run by Murdoch Childrens Research Institute at 1 site in Australia.
Trial summary
This aim of this study is to further develop a new way to study the bacteria that causes pharyngitis (strep throat). The scientific name for this bacterium is Streptococcus pyogenes and it is commonly known as Strep A. Strep A is a common type of bacteria that can cause various infections. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Streptococcus Pyogenes Pharyngitis, Streptococcus Infection
- What is being tested?
- Streptococcus pyogenes M1UK strain MCRI0102
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteAustralia
- Study dates
- 24 Jul 2025to 16 Feb 2026
- Phase
- Early Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Males or females, aged 18 - 40 years (inclusive) on the day of informed consent.
- Medically healthy, which can be determined by medical history, physical examination, BMI, transthoracic echocardiogram, non-clinically significant laboratory profiles, vital signs, and 12-lead ECG at screening, as deemed necessary by the research physician or investigator.
- Systolic blood pressure (SBP) of 90 mmHg - 140 mmHg and diastolic blood pressure (DBP) of 60 mmHg - 90 mmHg. Vital signs can be repeated up to two times.
- Resting heart rate (HR) of 55-100 bpm (confirmed by one repeat at screening).
- Females must be non-pregnant, non-lactating, or postmenopausal for at least 1 year (as confirmed by follicle-stimulating hormone [FSH]), or surgically sterile for at least 6 months prior to dosing.
- Females of childbearing potential will be required to use an effective form of contraception from the time of signing informed consent until the second planned outpatient visit approximately 1 month following the inpatient challenge admission.
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- Males must not have a pregnant partner and must agree to use condoms as a method of contraception from the time of signing informed consent until the second planned outpatient visit approximately 1 month following the inpatient challenge admission.
- Must be willing and able to read, understand, and sign the participant information and consent form. Willing to comply with all study requirements, including the inpatient period and outpatient visits for the duration of the study (approx. 3 months).
- Willing to abstain from the use of mouthwash from the day of screening until the first outpatient visit at one week post discharge.
Who cannot join
- History of any clinically important cardiac, endocrinologic, hematologic, hepatic, immunologic, metabolic, urologic, pulmonary, neurologic, dermatologic, psychiatric, and renal, or other major disease, as determined by the Investigator.
- Significant history of hospitalisation for illness within the six months prior to enrolment into study, or major surgery within the 12 months prior to enrolment into study, as assessed by research physician or investigator.
- History of tonsillectomy, adenoidectomy or splenectomy.
- Known or suspected autoimmune disease or impairment/alteration of immune function resulting from:
- Congenital or acquired immunodeficiency (including immunoglobulin A [IgA] deficiency)
- Receipt of immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within the preceding 6 months.
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- History of a severe drug reaction or severe allergic reaction (eg. anaphylaxis, convulsions) or clinically significant allergic disease diagnosed by a physician.
- Personal or family history of severe S. pyogenes infection (toxic shock syndrome, necrotizing fasciitis, bloodstream infection, pleural empyema, meningitis) or post-infectious sequelae (such as acute rheumatic fever, rheumatic heart disease, post-streptococcal glomerulonephritis).
- Clinically significant disease or any condition or disease that might affect drug absorption, distribution or excretion, e.g. gastrectomy, diarrhoea.
- Any vaccination within the last 28 days or use of any antibiotic therapy during the 14 days before challenge.
- Presence of an acute infectious disease or febrile illness (e.g., sub-lingual temperature ≥ 38.5°C) within the five days prior to inoculation.
- Significant acute or chronic infection within 14 days prior to inoculation that the research physician or investigator deems may compromise participant safety.
- Any clinically significant abnormal finding on biochemistry or haematology blood tests, urine analysis, ECG or transthoracic echocardiogram.
- Positive serologic results for human immunodeficiency virus (HIV) antibodies, hepatitis B surface antigen (HBsAg), and/or hepatitis C virus (HCV) antibodies.
- Ex-smoker with a >10 pack per year smoking history or a current smoker who is unable to stop smoking for the duration of the study.
- History or presence of alcohol abuse (defined as regular alcohol consumption of more than 40g per day) or drug habituation, or any prior intravenous usage of an illicit substance.
- A positive alcohol breath test at screening or admission.
- A positive urine drug test at screening or admission (e.g., amphetamines, barbiturates, benzodiazepines, cocaine, methylenedioxymethamphetamine [MDMA], methamphetamine, methadone, opiates, phencyclidine [PCP] and tetrahydrocannabinol [THC]) unless there is an explanation acceptable to the Investigator (e.g. the participant has stated in advance that they consumed a prescription or over-the-counter product which contained the detected drug) and the participant has a negative urine drug screen on retest.
- A positive point of care (POC) test for S. pyogenes on screening or day -1 throat swab.
- Known hypersensitivity to more than two of the following antibiotics: penicillin, azithromycin, clindamycin, or other beta-lactam antibiotic(s).
- Known hypersensitivity to soya protein.
- Have participated in previous S. pyogenes challenge studies (with application of challenge agent).
- Intolerance of throat swab procedure (exaggerated gag reflex).
- Systemic corticosteroid in the 14 days prior to admission, or for more than seven consecutive days within the past 3 months, or anticipated use during the study period.
- Any chronic (more than 1 month) use of inhaled high potency corticosteroids (budesonide 800 μg or fluticasone 750 μg per day).
- Any intranasal corticosteroid use is not allowed in the 14 days prior to admission, during the inpatient period, and is discouraged prior to the first outpatient visit. Topical corticosteroid use is allowed.
- Any use of drugs which may suppress the hypothalamic-pituitary-adrenal (HPA) axis such as adrenocorticotrophic hormone (ACTH) within the previous 3 months.
- Any anti-inflammatory drugs (besides sporadic use of non-steroidal anti-inflammatory drugs), immunomodulators (such as monoclonal antibodies) or anticoagulants in the previous 3 months, or anticipated use of such drugs during the study period.
- Use of prescription or non-prescription drugs and herbal supplements (such as St John´s Wort) within 14 days or 5 half-lives (whichever is the longer) prior to the inoculation administration. Use of vitamin supplements taken at standard doses is allowed.
- Participation in a research study that involved blood sampling of more than 450 mL/1 unit of blood, received or donated blood, blood products and/or plasma derivatives or any parenteral immunoglobulin preparation within 3 months of informed consent.
- History of severe infections requiring hospitalisation for intravenous antibiotics (within the last 10 years). Exceptions to this would include a short course of intravenous antibiotics for appendicitis, biliary sepsis, diverticulitis and cellulitis or a similar non-severe infection.
- History of cancer (except adequately treated squamous cell or basal cell carcinoma of the skin and cervical intraepithelial neoplasia).
- Presence of implants or prosthesis (e.g. artificial joints, pacemakers) deemed significant for infective complications as assessed by research physician or investigator. Participants with cosmetic implants or prosthesis may be included, as per principal investigator's discretion.
- Participation in another research study within the 30 days prior to enrolment involving an investigational product or other intervention that might affect risk of invasive S. pyogenes infection or compromise the integrity of the study (e.g. significant volumes of blood already taken in previous study).
- Any significant disease or disorder which, in the opinion of the Investigator, may either put the participants at risk because of participation in the study, or may influence the results of the study, or the participant's ability to participate in the study.
- Any employee of the sponsor or research site personnel directly affiliated with this study or their immediate family members defined as a spouse, parent, sibling, or child whether biological or legally adopted.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: CHIVAS- M1 (Controlled Human Infection for Vaccination Against Streptococcus Pyogenes M1UK): Expanding the Scope of Experimental Human Streptococcus Pyogenes Pharyngitis
This aim of this study is to further develop a new way to study the bacteria that causes pharyngitis (strep throat). The scientific name for this bacterium is Streptococcus pyogenes and it is commonly known as Strep A. Strep A is a common type of bacteria that can cause various infections. These range from skin infections and strep throat to more serious conditions like rheumatic heart disease. In recent years there has been an increase in severe Strep A infections in most countries. Many of these cases have been reported in the news.
Human challenge models are studies which allow researchers to study organisms that cause infections in humans. In this human challenge model study, healthy participants will be carefully exposed to a specific type of Strep A under controlled conditions to cause sore throat and learn more about how Strep A causes infection. The study team has already developed a safe human challenge model using a strain of Strep A called M75. This study will use a different strain of Strep A, called M1.
Read more
The main goal of this study is to check if the procedure is safe for participants and to understand how the participant's body responds to M1 Strep A. The study will explore:
- How much M1 Strep A is required to cause an infection.
- How M1 Strep A grows in the body.
- How the body reacts to M1 Strep A.
The information the investigators will get about M1 Strep A from this study will help plan future research. It may also help in designing better studies to test vaccines against Strep A.
Read the detailed description
Streptococcus pyogenes infection is a major cause of death and disability globally, particularly in settings of disadvantage with a disproportionately high burden in Indigenous Australians and the Pacific region. Acute infections due to S. pyogenes range from very common superficial skin infections (>150 million prevalent cases worldwide) and pharyngitis (> 600 million incident cases) to life-threatening invasive disease (>600,000 incident cases). Post-infectious sequelae of S. pyogenes include acute rheumatic fever (ARF, ~500,000 incident cases) leading to rheumatic heart disease (RHD) (~40 million prevalent cases), and acute post-streptococcal glomerulonephritis (APSGN). The health services impact of S. pyogenes disease in all its forms is immense and strikes at every level from primary to intensive care, with associated direct and indirect costs (e.g. primary and hospital care, work and school absences, antibiotic use and misuse leading to antimicrobial resistance).
A vaccine against S. pyogenes would be a global game changer and is the only plausible way to prevent S. pyogenes infections and sequelae. Efforts to control S. pyogenes-related disease through primary prevention have proved expensive and ineffective. Animal models of S. pyogenes disease have not delivered a vaccine. S. pyogenes-related disease is an important global driver of broad-spectrum antibiotic use leading to increased antimicrobial resistance (AMR). Multiple economic analyses have shown that a vaccine against S. pyogenes would be economically viable and result in enormous healthcare savings. The World Health Organization (WHO) recognises the need for a vaccine against S. pyogenes and has prioritised vaccine development as well as adopting a resolution to end ARF and RHD at the 2018 World Health Assembly.
In the recent CHIVAS-M75 project, a diverse team of investigators developed the world's only modern S. pyogenes controlled human infection model (CHIM) using an M75 strain of S. pyogenes, following a careful and intensive approach to select and manufacture an initial challenge strain and produce a clinically relevant protocol to protect participants and maximise the model's strategic and scientific impact.
M1 strains are the leading cause of S. pyogenes infections globally and have been the principal focus of decades of 'wet' and 'dry' laboratory research that underlies current understanding of host-pathogen interactions. In 2019 a new M1 clone was described in the UK (M1UK) which has now established global dominance. M1UK is associated with outbreaks of invasive disease and scarlet fever as well as pharyngitis. Having shown the safety and reliability of human challenge using M75, an emm-type that is a relatively uncommon cause of complicated S. pyogenes disease, the M1UK strain provides a unique opportunity to study a leading emm-type associated with increasing rates of complicated S. pyogenes disease. An M1UK CHIM used in a vaccine efficacy trial could demonstrate reduced rates of pharyngitis (the most clinically relevant endpoint) that would be expected to translate to protection against invasive disease and post-streptococcal complications.
- Being tested
- Streptococcus pyogenes M1UK strain MCRI0102
- Keywords
- Streptococcus pyogenes, Streptococcus pyogenes pharyngitis, Controlled Human Infection Model, S. pyogenes M1UK
- Medical subject headings
- Streptococcal Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Streptococcus pyogenes M1UK strain MCRI0102Biological
Human challenge with S. pyogenes M1UK strain MCRI0102
| Study group | Role | What they receive |
|---|---|---|
| Human challenge participants | Experimental | Participants will be allocated a dose of M1 S. pyogenes sequentially by date of challenge based on the attack rate in the preceding participants. Up to 4 dose levels will be tested commencing at 1-5 x10^5 CFU/mL, increasing by 1 log to a maximum dose of 1-5 x 10^7 CFU/mL, or decreasing by 1 log to a minimum dose of 1-5 x 10^4 CFU/mL. Receives: Biological: Streptococcus pyogenes M1UK strain MCRI0102 |
What is being measured
The primary outcome is the main question the study is designed to answer.
The proportion of participants at each dose level of M1 S. pyogenes who reach the study pharyngitis endpoint
The proportion of participants at each M1 S. pyogenes dose level who develop pharyngitis, using a combined clinical-microbiological definition comprising sore throat, physical examination signs of pharyngitis and tonsillitis, and microbiological confirmation of S. pyogenes by culture and nucleic acid amplification test of throat swabs
Measured: Up to 5 days after the challenge dose of M1 S. pyogenes is administered
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 May 2025
- Study start24 Jul 2025
- Primary completion31 Oct 2025
- Study completion16 Feb 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Streptococcus Pyogenes PharyngitisStudies of the same condition, open and under way.
- More trials run by Murdoch Childrens Research InstituteThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- This is an observational, sequential, dose escalation/de-escalation study with 4 predetermined doses of bacteria for human challenge. The aim is to reliably and safely cause pharyngitis in greater than or equal to 60% of participants. The starting dose is based upon the successful dose from the previous human challenge study (CHIVAS- M75) and escalation/de-escalation decisions will be based upon the number of participants diagnosed with pharyngitis in each cohort of 10-20 participants.
- Masking
- None (open label)
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- Murdoch Childrens Research Institute
- Sponsor type
- University, hospital or other
- Collaborators
- University of Auckland, New Zealand, University of Melbourne, University of Wollongong, Université Libre de Bruxelles, University of California, San Diego, Leducq Foundation, National Health and Medical Research Council, Australia, Monash University, Duke University, The University of Queensland, Doherty Clinical Trials Ltd
- Responsible party
- Sponsor
- Investigators
- Joshua Osowicki, FRACP PhD, Principal investigator, Murdoch Childrens Research Institute
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06992141
- Sponsor's protocol ID
- CHIVAS-M1
- Acronym
- CHIVAS-M1
- Status last verified
- Mar 2026
- First submitted
- 19 May 2025
- Last updated
- 16 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data (IPD) will be shared by the sponsor with study collaborators upon request and as necessary to facilitate research collaborations and study publications. Planned sharing of de-identified IPD includes microbiological, immunologic and gene expression data gathered from study participants. De-identified IPD will be published in peer-reviewed journals.
Publications
Osowicki J, Azzopardi KI, Fabri L, Frost HR, Rivera-Hernandez T, Neeland MR, Whitcombe AL, Grobler A, Gutman SJ, Baker C, Wong JMF, Lickliter JD, Waddington CS, Pandey M, Schuster T, Cheng AC, Pollard AJ, McCarthy JS, Good MF, Dale JB, Batzloff M, Moreland NJ, Walker MJ, Carapetis JR, Smeesters PR, Steer AC. A controlled human infection model of Streptococcus pyogenes pharyngitis (CHIVAS-M75): an observational, dose-finding study. Lancet Microbe. 2021 Jul;2(7):e291-e299. doi: 10.1016/S2666-5247(20)30240-8. Epub 2021 Apr 15.
PubMed 35544165
Study at a glance
From the registry record, last updated by the sponsor on 16 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- CHIVAS- M1 (Controlled Human Infection for Vaccination Against Streptococcus Pyogenes M1UK): Expanding the Scope of Experimental Human Streptococcus Pyogenes Pharyngitis
- ClinicalTrials.gov ID
- NCT06992141
- Acronym / sponsor ID
- CHIVAS-M1 / CHIVAS-M1
- Keywords
- Streptococcus pyogenes, Streptococcus pyogenes pharyngitis, Controlled Human Infection Model, S. pyogenes M1UK
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 40 participants (actual)
- Lead sponsor
- Murdoch Childrens Research InstituteUniversity, hospital or other
- Collaborators
- University of Auckland, New Zealand, University of Melbourne, University of Wollongong, Université Libre de Bruxelles, University of California, San Diego, Leducq Foundation, National Health and Medical Research Council, Australia, Monash University, Duke University, The University of Queensland, Doherty Clinical Trials Ltd
- Study start
- 24 Jul 2025 (actual)
- Primary completion
- 31 Oct 2025 (actual)
- Study completion
- 16 Feb 2026 (actual)
- First posted
- 28 May 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This aim of this study is to further develop a new way to study the bacteria that causes pharyngitis (strep throat). The scientific name for this bacterium is Streptococcus pyogenes and it is commonly known as Strep A. Strep A is a common type of bacteria that can cause various infections. These range from skin infections and strep throat to more serious conditions like rheumatic heart disease. In recent years there has been an increase in severe Strep A infections in most countries. Many of these cases have been reported in the news.
Human challenge models are studies which allow researchers to study organisms that cause infections in humans. In this human challenge model study, healthy participants will be carefully exposed to a specific type of Strep A under controlled conditions to cause sore throat and learn more about how Strep A causes infection. The study team has already developed a safe human challenge model using a strain of Strep A called M75. This study will use a different strain of Strep A, called M1.
The main goal of this study is to check if the procedure is safe for participants and to understand how the participant's body responds to M1 Strep A. The study will explore:
- How much M1 Strep A is required to cause an infection.
- How M1 Strep A grows in the body.
- How the body reacts to M1 Strep A.
The information the investigators will get about M1 Strep A from this study will help plan future research. It may also help in designing better studies to test vaccines against Strep A.
Detailed description
Streptococcus pyogenes infection is a major cause of death and disability globally, particularly in settings of disadvantage with a disproportionately high burden in Indigenous Australians and the Pacific region. Acute infections due to S. pyogenes range from very common superficial skin infections (>150 million prevalent cases worldwide) and pharyngitis (> 600 million incident cases) to life-threatening invasive disease (>600,000 incident cases). Post-infectious sequelae of S. pyogenes include acute rheumatic fever (ARF, ~500,000 incident cases) leading to rheumatic heart disease (RHD) (~40 million prevalent cases), and acute post-streptococcal glomerulonephritis (APSGN). The health services impact of S. pyogenes disease in all its forms is immense and strikes at every level from primary to intensive care, with associated direct and indirect costs (e.g. primary and hospital care, work and school absences, antibiotic use and misuse leading to antimicrobial resistance).
A vaccine against S. pyogenes would be a global game changer and is the only plausible way to prevent S. pyogenes infections and sequelae. Efforts to control S. pyogenes-related disease through primary prevention have proved expensive and ineffective. Animal models of S. pyogenes disease have not delivered a vaccine. S. pyogenes-related disease is an important global driver of broad-spectrum antibiotic use leading to increased antimicrobial resistance (AMR). Multiple economic analyses have shown that a vaccine against S. pyogenes would be economically viable and result in enormous healthcare savings. The World Health Organization (WHO) recognises the need for a vaccine against S. pyogenes and has prioritised vaccine development as well as adopting a resolution to end ARF and RHD at the 2018 World Health Assembly.
In the recent CHIVAS-M75 project, a diverse team of investigators developed the world's only modern S. pyogenes controlled human infection model (CHIM) using an M75 strain of S. pyogenes, following a careful and intensive approach to select and manufacture an initial challenge strain and produce a clinically relevant protocol to protect participants and maximise the model's strategic and scientific impact.
M1 strains are the leading cause of S. pyogenes infections globally and have been the principal focus of decades of 'wet' and 'dry' laboratory research that underlies current understanding of host-pathogen interactions. In 2019 a new M1 clone was described in the UK (M1UK) which has now established global dominance. M1UK is associated with outbreaks of invasive disease and scarlet fever as well as pharyngitis. Having shown the safety and reliability of human challenge using M75, an emm-type that is a relatively uncommon cause of complicated S. pyogenes disease, the M1UK strain provides a unique opportunity to study a leading emm-type associated with increasing rates of complicated S. pyogenes disease. An M1UK CHIM used in a vaccine efficacy trial could demonstrate reduced rates of pharyngitis (the most clinically relevant endpoint) that would be expected to translate to protection against invasive disease and post-streptococcal complications.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- This is an observational, sequential, dose escalation/de-escalation study with 4 predetermined doses of bacteria for human challenge. The aim is to reliably and safely cause pharyngitis in greater than or equal to 60% of participants. The starting dose is based upon the successful dose from the previous human challenge study (CHIVAS- M75) and escalation/de-escalation decisions will be based upon the number of participants diagnosed with pharyngitis in each cohort of 10-20 participants.
| Arm | Type | Receives |
|---|---|---|
| Human challenge participants | Experimental | Biological: Streptococcus pyogenes M1UK strain MCRI0102Participants will be allocated a dose of M1 S. pyogenes sequentially by date of challenge based on the attack rate in the preceding participants. Up to 4 dose levels will be tested commencing at 1-5 x10^5 CFU/mL, increasing by 1 log to a maximum dose of 1-5 x 10^7 CFU/mL, or decreasing by 1 log to a minimum dose of 1-5 x 10^4 CFU/mL. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (9 listed)
- Males or females, aged 18 - 40 years (inclusive) on the day of informed consent.
- Medically healthy, which can be determined by medical history, physical examination, BMI, transthoracic echocardiogram, non-clinically significant laboratory profiles, vital signs, and 12-lead ECG at screening, as deemed necessary by the research physician or investigator.
- Systolic blood pressure (SBP) of 90 mmHg - 140 mmHg and diastolic blood pressure (DBP) of 60 mmHg - 90 mmHg. Vital signs can be repeated up to two times.
- Resting heart rate (HR) of 55-100 bpm (confirmed by one repeat at screening).
- Females must be non-pregnant, non-lactating, or postmenopausal for at least 1 year (as confirmed by follicle-stimulating hormone [FSH]), or surgically sterile for at least 6 months prior to dosing.
Key exclusion criteria (36 listed)
- History of any clinically important cardiac, endocrinologic, hematologic, hepatic, immunologic, metabolic, urologic, pulmonary, neurologic, dermatologic, psychiatric, and renal, or other major disease, as determined by the Investigator.
- Significant history of hospitalisation for illness within the six months prior to enrolment into study, or major surgery within the 12 months prior to enrolment into study, as assessed by research physician or investigator.
- History of tonsillectomy, adenoidectomy or splenectomy.
- Known or suspected autoimmune disease or impairment/alteration of immune function resulting from:
- History of a severe drug reaction or severe allergic reaction (eg. anaphylaxis, convulsions) or clinically significant allergic disease diagnosed by a physician.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Streptococcus pyogenes M1UK strain MCRI0102Human challenge with S. pyogenes M1UK strain MCRI0102 | Biological | Human challenge participants |
Primary outcome
The proportion of participants at each dose level of M1 S. pyogenes who reach the study pharyngitis endpoint
Time frame: Up to 5 days after the challenge dose of M1 S. pyogenes is administered
The proportion of participants at each M1 S. pyogenes dose level who develop pharyngitis, using a combined clinical-microbiological definition comprising sore throat, physical examination signs of pharyngitis and tonsillitis, and microbiological confirmation of S. pyogenes by culture and nucleic acid amplification test of throat swabs
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Mar 2026.
- Background: PubMed 35544165Osowicki J, Azzopardi KI, Fabri L, Frost HR, Rivera-Hernandez T, Neeland MR, Whitcombe AL, Grobler A, Gutman SJ, Baker C, Wong JMF, Lickliter JD, Waddington CS, Pandey M, Schuster T, Cheng AC, Pollard AJ, McCarthy JS, Good MF, Dale JB, Batzloff M, Moreland NJ, Walker MJ, Carapetis JR, Smeesters PR, Steer AC. A controlled human infection model of Streptococcus pyogenes pharyngitis (CHIVAS-M75): an observational, dose-finding study. Lancet Microbe. 2021 Jul;2(7):e291-e299. doi: 10.1016/S2666-5247(20)30240-8. Epub 2021 Apr 15.
- Individual participant dataSharing planned: Yes. De-identified individual participant data (IPD) will be shared by the sponsor with study collaborators upon request and as necessary to facilitate research collaborations and study publications. Planned sharing of de-identified IPD includes microbiological, immunologic and gene expression data gathered from study participants. De-identified IPD will be published in peer-reviewed journals.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Joshua Osowicki, FRACP PhD principal investigator
Murdoch Childrens Research Institute
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Streptococcus pyogenes M1UK strain MCRI0102 in people with Streptococcus Pyogenes Pharyngitis and Streptococcus Infection, run by Murdoch Childrens Research Institute at 1 site in Australia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 9 inclusion and 36 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 16 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Australia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The proportion of participants at each dose level of M1 S. pyogenes who reach the study pharyngitis endpoint (time frame: Up to 5 days after the challenge dose of M1 S. pyogenes is administered). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06992141, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 Mar 2026.