Cryptosporidium Infection, CryptosporidiosisPhase 1NCT05036668
Study of Efficacy and Safety of ABO809 in Healthy Participants
A Phase 1 study testing Cryptosporidium parvum oocysts (ABO809) in people with Cryptosporidium Infection, Cryptosporidiosis, run by Novartis Pharmaceuticals at 1 site in United States.
Trial summary
The purpose of this Phase I controlled human infection model (CHIM) study was to determine if oral administration of a good manufacturing practice (GMP) supply of Cryptosporidium parvum oocysts (ABO809) to healthy volunteers resulted in a Cryptosporidium infection and diarrheal illness. Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Cryptosporidium Infection, Cryptosporidiosis
- What is being tested?
- Cryptosporidium parvum oocysts (ABO809)
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteUnited States
- Study dates
- 7 Apr 2022to 27 Dec 2022
- Phase
- Phase 1
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Demonstrated understanding of Cryptosporidium disease, safety measures and transmission risks
- Good health
- Ability to communicate well with the Investigator
Who cannot join
- History of Cryptosporidium infection, gastrointestinal conditions (including diarrheal syndromes, gastroenteritis and gastrointestinal tract surgery), immunodeficiency, infections, significant medical concerns, hypersensitivity to nitazoxanide or other specified antibiotics.
- Other protocol-defined inclusion/exclusion criteria may apply.
Trial locations and contacts
1 site in 1 country.
United States1 site
Novartis Investigative Site
Baltimore, Maryland, 21201
About this study
Official title: An Open Label Cryptosporidium Controlled Human Infection Model (CHIM) to Assess the Efficacy and Safety of ABO809 in Healthy Participants
The purpose of this Phase I controlled human infection model (CHIM) study was to determine if oral administration of a good manufacturing practice (GMP) supply of Cryptosporidium parvum oocysts (ABO809) to healthy volunteers resulted in a Cryptosporidium infection and diarrheal illness. The study measured fecal oocysts (parasitological endpoint) as well as diarrhea and associated signs and symptoms (clinical endpoint).
Read the detailed description
This study was funded by the Wellcome Trust. This Phase 1 Cryptosporidium controlled human infection model (CHIM) study employed a single-center, open-label design to characterize the incidence of infection and associated symptoms following the administration of single doses of Cryptosporidium parvum oocysts (CE).
Healthy volunteers were enrolled in cohorts of approximately 10 participants who received ABO809 on the same day (Day 1). The study consisted of three sequential cohorts which were dosed one after the other for a total of 30 participants. A dose level group received the same ABO809 dose and could be comprised of multiple cohorts. The first dose level group started with a cohort of 10 participants who received ABO809 at a dose of 1x10^4 oocysts. The study continued to enroll participants in the same dose level group if the desired incidences of infection and diarrheal illness were observed, up to a total of approximately 30 participants. If the desired incidences of infection and diarrheal illness were not observed, a new dose level group, receiving ABO809 at a dose of 1x10^6 oocysts, could be initiated. If needed to optimize the model, intermediate ABO809 doses could be evaluated.
- Being tested
- Cryptosporidium parvum oocysts (ABO809)
- Keywords
- Controlled Human Infection Model, safety, tolerability, healthy volunteers, cryptosporidiosis, ABO809
- Medical subject headings
- Cryptosporidiosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Cryptosporidium parvum oocysts (ABO809)Biological
ABO809 3x10^6 CE/3mL concentrate for oral suspension, single dose at Day 1
| Study group | Role | What they receive |
|---|---|---|
| ABO809 | Experimental | Participants will receive ABO809 at a single oral dose of 1x10^4 oocysts. Other doses such as 1x10^6 oocysts may be considered to optimize the model Receives: Biological: Cryptosporidium parvum oocysts (ABO809) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of Participants With Cryptosporidium Infection From 72 Hours to 10 Days Post ABO809 Oral Administration
Cryptosporidium infection was measured by examining the presence of a Cryptosporidium antigen in stool using a commercially available diagnostic Enzyme Immunoassay (EIA) test. Up to 3 stool samples per day were collected, each separated by approximately 4-hour intervals, were analyzed by EIA for parasitological assessment of oocyst shedding.
Measured: At ≥72 hours post-administration (or sooner if associated with symptoms suggestive of diarrheal illness) up to Day 10 (inclusive).
Secondary outcomes (12)
Percentage of Participants Showing Clinical Diarrheal Illness From Day 1 to Day 28 Post ABO809 Oral Administration
Clinical diarrheal illness was defined as the occurrence of at least two diarrheal bowel events within 24 hours on at least two days after the administration of ABO809. Diarrhea is defined as at least one stool sample grading 3-5 on the Stool Grading system in one day. Grades 1 and 2 are considered normal stool and Grades 3-5 are considered diarrheal stool.
Grade 1 stool is defined as formed stool which does not take the shape of the container.
Grade 2 stool is defined as soft stool which does not easily take the shape of the container.
Grade 3 diarrheal stool is defined as thick liquid stool taking the shape of the container.
Grade 4 diarrheal stool is defined as opaque watery stool. Grade 5 diarrheal stool is defined as rice water or clear watery stools.
Measured: From Day 1 up to Day 28
Number of Diarrhea Stools Per Participant
Diarrhea is defined as at least one stool sample grading 3-5 on the Stool Grading system in one day. Grades 1 and 2 are considered normal stool and Grades 3-5 are considered diarrheal stool.
Grade 1 stool is defined as formed stool which does not take the shape of the container.
Grade 2 stool is defined as soft stool which does not easily take the shape of the container.
Grade 3 diarrheal stool is defined as thick liquid stool taking the shape of the container.
Grade 4 diarrheal stool is defined as opaque watery stool. Grade 5 diarrheal stool is defined as rice water or clear watery stools.
Measured: From Day 1 up to Day 28
Overall Diarrheal Stool Weight
Stool weight in grams of each stool from each participant were measured during inpatient period from Day 1 up to Day 10. Stool weight in grams of stool collected 24 hours prior to outpatient visit from each participant were measured during outpatient period from Day 14 to Day 28.
Measured: From Day 1 up to Day 28
Maximum Stool Grade by Stool Grade Category
All collected stool samples were graded according to the Stool Grading system. Grades 1 and 2 are considered normal stool and Grades 3-5 are considered diarrheal stool. Grades 3-5 stools are defined as thick liquid diarrhea taking the shape of the container, opaque watery, rice water or clear watery stools. The maximum stool grade is the highest stool grade of all episodes in a participant.
Measured: From Day 1 up to Day 28
Time to Onset of Clinical Diarrheal Illness
Clinical diarrheal illness was defined as the occurrence of at least two diarrheal bowel events within 24 hours on at least two days after the administration of ABO809. The time to onset is the number of days until the start diarrheal illness.
Measured: From Day 1 up to Day 28
Time to Resolution of Clinical Diarrheal Illness
Clinical diarrheal illness was defined as the occurrence of at least two diarrheal bowel events within 24 hours on at least two days after the administration of ABO809. The time to resolution is the number of days until the resolution of diarrheal illness, which is defined as 2 or more consecutive days with no diarrheal stools (stool grades 1 or 2).
Measured: From Day 1 up to Day 28
Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal Illness
Clinical signs and symptoms associated with clinical diarrheal illness such as: abdominal pain, abdominal cramping, nausea, vomiting, fever, electrolyte disbalance, dehydration.
Measured: From Day 1 up to Day 28
Percentage of Participants With Cryptosporidium Infection From 72 Hours to Day 28 Post ABO809 Oral Administration
Percentage of participants with Cryptosporidium infection following an oral administration of ABO809. Cryptosporidium infection were measured by examining the presence of a Cryptosporidium antigen in stool using a commercially available diagnostic Enzyme Immunoassay (EIA) test.
Measured: From 72 hours post-administration up to Day 28
Percentage of Participants With Fecal Shedding of Cryptosporidium Parvum Oocysts
Percentage of participants with fecal shedding of Cryptosporidium parvum oocysts following an oral administration of ABO809. Fecal shedding will be measured by examining the presence of a Cryptosporidium antigen in stool using a commercially available diagnostic Enzyme Immunoassay (EIA) test.
Measured: From 72 hours post-administration up to Day 28
Time to Onset of Cryptosporidium Infection
Time to onset is the number of days until the start of Cryptosporidium infection which were measured by examining the presence of a Cryptosporidium antigen in stool using a commercially available diagnostic Enzyme Immunoassay (EIA) test.
Measured: From Day 1 up to Day 10
Time to Resolution of Cryptosporidium Infection
Time to resolution is the number of days until the resolution of Cryptosporidium infection in participants who developed an infection following an oral administration of ABO809. Resolution of Cryptosporidium infection is defined as no evidence of Cryptosporidium in stool samples collected over ≥2 consecutive days.
Measured: From Day 1 up to Day 28
Number of Participants With Adverse Events of Special Interest (AESIs)
The following adverse events associated with Cryptosporidium infection are considered AESIs in this trial: Gastroenteritis in the absence of Cryptosporidium infection, extraintestinal cryptosporidiosis, persistent or recurrent cryptosporidiosis, persistent cryptosporidium shedding, moderate or severe dehydration and non-intestinal sequelae including eye pain or joint pain.
Measured: Adverse events were reported from oral administration of ABO809 up to a maximum duration of 56 days.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Sep 2021
- Study start7 Apr 2022
- Primary completion7 Nov 2022
- Study completion27 Dec 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Cryptosporidium Infection, CryptosporidiosisStudies of the same condition, open and under way.
- More trials run by Novartis PharmaceuticalsThe 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
- Phase 1
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Cryptosporidium controlled human infection model
- Masking
- None (open label)
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- Novartis Pharmaceuticals
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Mohamed Al-Ibrahim, Principal investigator, Pharmaron CPC, Inc.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05036668
- Sponsor's protocol ID
- CABO809A02101
- Status last verified
- Jun 2024
- First submitted
- 31 Aug 2021
- Last updated
- 2 Oct 2024
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Stuart BD, Stevenson K, Tillmann HC, Middleton C, Nguyen A, Jumani RS, Zhao X, Blais J, Braud-Perez S, Zhang Y, Etse J, Arora K, Aziz N, Mohamed AI, Diagana TT, Manjunatha UH. Development of a Phase 1 Cryptosporidiosis Controlled Human Challenge Model in Healthy Volunteers Using Current Good Manufacturing Practice Cryptosporidium Parvum Oocysts and Conducted Under an Investigational New Drug Application. J Infect Dis. 2026 May 27:jiag246. doi: 10.1093/infdis/jiag246. Online ahead of print.
PubMed 42201116
Study at a glance
From the registry record, last updated by the sponsor on 2 Oct 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open Label Cryptosporidium Controlled Human Infection Model (CHIM) to Assess the Efficacy and Safety of ABO809 in Healthy Participants
- ClinicalTrials.gov ID
- NCT05036668
- Acronym / sponsor ID
- CABO809A02101
- Keywords
- Controlled Human Infection Model, safety, tolerability, healthy volunteers, cryptosporidiosis, ABO809
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- Novartis PharmaceuticalsIndustry (pharma, biotech, devices)
- Study start
- 7 Apr 2022 (actual)
- Primary completion
- 7 Nov 2022 (actual)
- Study completion
- 27 Dec 2022 (actual)
- First posted
- 5 Sep 2021 (actual)
- Results
- Posted 2 Oct 2024
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this Phase I controlled human infection model (CHIM) study was to determine if oral administration of a good manufacturing practice (GMP) supply of Cryptosporidium parvum oocysts (ABO809) to healthy volunteers resulted in a Cryptosporidium infection and diarrheal illness. The study measured fecal oocysts (parasitological endpoint) as well as diarrhea and associated signs and symptoms (clinical endpoint).
Detailed description
This study was funded by the Wellcome Trust. This Phase 1 Cryptosporidium controlled human infection model (CHIM) study employed a single-center, open-label design to characterize the incidence of infection and associated symptoms following the administration of single doses of Cryptosporidium parvum oocysts (CE).
Healthy volunteers were enrolled in cohorts of approximately 10 participants who received ABO809 on the same day (Day 1). The study consisted of three sequential cohorts which were dosed one after the other for a total of 30 participants. A dose level group received the same ABO809 dose and could be comprised of multiple cohorts. The first dose level group started with a cohort of 10 participants who received ABO809 at a dose of 1x10^4 oocysts. The study continued to enroll participants in the same dose level group if the desired incidences of infection and diarrheal illness were observed, up to a total of approximately 30 participants. If the desired incidences of infection and diarrheal illness were not observed, a new dose level group, receiving ABO809 at a dose of 1x10^6 oocysts, could be initiated. If needed to optimize the model, intermediate ABO809 doses could be evaluated.
Study design
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Cryptosporidium controlled human infection model
| Arm | Type | Receives |
|---|---|---|
| ABO809 | Experimental | Biological: Cryptosporidium parvum oocysts (ABO809)Participants will receive ABO809 at a single oral dose of 1x10^4 oocysts. Other doses such as 1x10^6 oocysts may be considered to optimize the model |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Demonstrated understanding of Cryptosporidium disease, safety measures and transmission risks
- Good health
- Ability to communicate well with the Investigator
Key exclusion criteria (2 listed)
- History of Cryptosporidium infection, gastrointestinal conditions (including diarrheal syndromes, gastroenteritis and gastrointestinal tract surgery), immunodeficiency, infections, significant medical concerns, hypersensitivity to nitazoxanide or other specified antibiotics.
- Other protocol-defined inclusion/exclusion criteria may apply.
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 |
|---|---|---|
| Cryptosporidium parvum oocysts (ABO809)ABO809 3x10^6 CE/3mL concentrate for oral suspension, single dose at Day 1 | Biological | ABO809 |
Primary outcome
Percentage of Participants With Cryptosporidium Infection From 72 Hours to 10 Days Post ABO809 Oral Administration
Time frame: At ≥72 hours post-administration (or sooner if associated with symptoms suggestive of diarrheal illness) up to Day 10 (inclusive).
Cryptosporidium infection was measured by examining the presence of a Cryptosporidium antigen in stool using a commercially available diagnostic Enzyme Immunoassay (EIA) test. Up to 3 stool samples per day were collected, each separated by approximately 4-hour intervals, were analyzed by EIA for parasitological assessment of oocyst shedding.
12 secondary outcomes
Percentage of Participants Showing Clinical Diarrheal Illness From Day 1 to Day 28 Post ABO809 Oral Administration
Time frame: From Day 1 up to Day 28
Number of Diarrhea Stools Per Participant
Time frame: From Day 1 up to Day 28
Overall Diarrheal Stool Weight
Time frame: From Day 1 up to Day 28
Maximum Stool Grade by Stool Grade Category
Time frame: From Day 1 up to Day 28
Time to Onset of Clinical Diarrheal Illness
Time frame: From Day 1 up to Day 28
Time to Resolution of Clinical Diarrheal Illness
Time frame: From Day 1 up to Day 28
Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal Illness
Time frame: From Day 1 up to Day 28
Percentage of Participants With Cryptosporidium Infection From 72 Hours to Day 28 Post ABO809 Oral Administration
Time frame: From 72 hours post-administration up to Day 28
Percentage of Participants With Fecal Shedding of Cryptosporidium Parvum Oocysts
Time frame: From 72 hours post-administration up to Day 28
Time to Onset of Cryptosporidium Infection
Time frame: From Day 1 up to Day 10
Time to Resolution of Cryptosporidium Infection
Time frame: From Day 1 up to Day 28
Number of Participants With Adverse Events of Special Interest (AESIs)
Time frame: Adverse events were reported from oral administration of ABO809 up to a maximum duration of 56 days.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Oct 2024.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 42201116Stuart BD, Stevenson K, Tillmann HC, Middleton C, Nguyen A, Jumani RS, Zhao X, Blais J, Braud-Perez S, Zhang Y, Etse J, Arora K, Aziz N, Mohamed AI, Diagana TT, Manjunatha UH. Development of a Phase 1 Cryptosporidiosis Controlled Human Challenge Model in Healthy Volunteers Using Current Good Manufacturing Practice Cryptosporidium Parvum Oocysts and Conducted Under an Investigational New Drug Application. J Infect Dis. 2026 May 27:jiag246. doi: 10.1093/infdis/jiag246. Online ahead of print.
- Individual participant dataSharing planned: No
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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.
Mohamed Al-Ibrahim principal investigator
Pharmaron CPC, Inc.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Cryptosporidium parvum oocysts (ABO809) in people with Cryptosporidium Infection, Cryptosporidiosis, run by Novartis Pharmaceuticals at 1 site in United States.
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 3 inclusion and 2 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 2 Oct 2024. 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 United States. 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?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 2 Oct 2024). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
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?
Percentage of Participants With Cryptosporidium Infection From 72 Hours to 10 Days Post ABO809 Oral Administration (time frame: At ≥72 hours post-administration (or sooner if associated with symptoms suggestive of diarrheal illness) up to Day 10 (inclusive).). 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 NCT05036668, 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 2 Oct 2024.