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Study of Efficacy and Safety of ABO809 in Healthy Participants

An Open Label Cryptosporidium Controlled Human Infection Model (CHIM) to Assess the Efficacy and Safety of ABO809 in Healthy Participants

Status
Completed
Phases
Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05036668
Enrollment
30
Registered
2021-09-05
Start date
2022-04-07
Completion date
2022-12-27
Last updated
2024-10-02

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cryptosporidium Infection, Cryptosporidiosis

Keywords

Controlled Human Infection Model, safety, tolerability, healthy volunteers, cryptosporidiosis, ABO809

Brief 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. 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.

Interventions

ABO809 3x10\^6 CE/3mL concentrate for oral suspension, single dose at Day 1

Sponsors

Novartis Pharmaceuticals
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE

Masking description

Open-Label

Intervention model description

Cryptosporidium controlled human infection model

Eligibility

Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
Yes

Inclusion criteria

* Demonstrated understanding of Cryptosporidium disease, safety measures and transmission risks * Good health * Ability to communicate well with the Investigator

Exclusion criteria

\- 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/

Design outcomes

Primary

MeasureTime frameDescription
Percentage of Participants With Cryptosporidium Infection From 72 Hours to 10 Days Post ABO809 Oral AdministrationAt ≥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.

Secondary

MeasureTime frameDescription
Number of Diarrhea Stools Per ParticipantFrom Day 1 up to Day 28Diarrhea 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.
Overall Diarrheal Stool WeightFrom Day 1 up to Day 28Stool 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.
Maximum Stool Grade by Stool Grade CategoryFrom Day 1 up to Day 28All 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.
Time to Onset of Clinical Diarrheal IllnessFrom Day 1 up to Day 28Clinical 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.
Time to Resolution of Clinical Diarrheal IllnessFrom Day 1 up to Day 28Clinical 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).
Percentage of Participants Showing Clinical Diarrheal Illness From Day 1 to Day 28 Post ABO809 Oral AdministrationFrom Day 1 up to Day 28Clinical 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.
Percentage of Participants With Cryptosporidium Infection From 72 Hours to Day 28 Post ABO809 Oral AdministrationFrom 72 hours post-administration up to Day 28Percentage 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.
Percentage of Participants With Fecal Shedding of Cryptosporidium Parvum OocystsFrom 72 hours post-administration up to Day 28Percentage 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.
Time to Onset of Cryptosporidium InfectionFrom Day 1 up to Day 10Time 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.
Time to Resolution of Cryptosporidium InfectionFrom Day 1 up to Day 28Time 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.
Number of Participants With Adverse Events of Special Interest (AESIs)Adverse events were reported from oral administration of ABO809 up to a maximum duration of 56 days.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.
Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessFrom Day 1 up to Day 28Clinical signs and symptoms associated with clinical diarrheal illness such as: abdominal pain, abdominal cramping, nausea, vomiting, fever, electrolyte disbalance, dehydration.

Countries

United States

Participant flow

Recruitment details

Participants took part in one investigative site in one country.

Participants by arm

ArmCount
ABO809 1x10^4 CE-Cohort 1
ABO809 single oral dose of 1x10\^4 oocysts.
10
ABO809 1x10^6 CE-Cohort 2
ABO809 single oral dose of 1x10\^6 oocysts.
10
ABO809 1x10^6 CE-Cohort 3
ABO809 single oral dose of 1x10\^6 oocysts.
10
Total30

Withdrawals & dropouts

PeriodReasonFG000FG001FG002
Overall Studylost to follow Up001

Baseline characteristics

CharacteristicABO809 1x10^4 CE-Cohort 1ABO809 1x10^6 CE-Cohort 2ABO809 1x10^6 CE-Cohort 3Total
Age, Continuous34.3 years
STANDARD_DEVIATION 6.53
33.4 years
STANDARD_DEVIATION 7.03
34.1 years
STANDARD_DEVIATION 8.49
33.9 years
STANDARD_DEVIATION 7.15
Race/Ethnicity, Customized
Black or African American
6 Participants5 Participants8 Participants19 Participants
Race/Ethnicity, Customized
Native Hawaiian or Other Pacific Islander
1 Participants0 Participants0 Participants1 Participants
Race/Ethnicity, Customized
Other
0 Participants1 Participants1 Participants2 Participants
Race/Ethnicity, Customized
White
3 Participants4 Participants1 Participants8 Participants
Sex: Female, Male
Female
5 Participants6 Participants2 Participants13 Participants
Sex: Female, Male
Male
5 Participants4 Participants8 Participants17 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
EG003
affected / at risk
EG004
affected / at risk
deaths
Total, all-cause mortality
0 / 100 / 100 / 100 / 200 / 30
other
Total, other adverse events
10 / 109 / 109 / 1018 / 2028 / 30
serious
Total, serious adverse events
0 / 100 / 100 / 100 / 200 / 30

Outcome results

Primary

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.

Time frame: At ≥72 hours post-administration (or sooner if associated with symptoms suggestive of diarrheal illness) up to Day 10 (inclusive).

Population: The pharmacodynamic (PD) analysis set included all participants with available parasitological and clinical data and with no protocol deviations with relevant impact on PD data.

ArmMeasureValue (NUMBER)
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Cryptosporidium Infection From 72 Hours to 10 Days Post ABO809 Oral Administration50 percentage of participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Cryptosporidium Infection From 72 Hours to 10 Days Post ABO809 Oral Administration57.1 percentage of participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Cryptosporidium Infection From 72 Hours to 10 Days Post ABO809 Oral Administration60.0 percentage of participants
Secondary

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.

Time frame: From Day 1 up to Day 28

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
ABO809 1x10^4 CE-Cohort 1Maximum Stool Grade by Stool Grade CategoryStool Grade 22 Participants
ABO809 1x10^4 CE-Cohort 1Maximum Stool Grade by Stool Grade CategoryStool Grade 42 Participants
ABO809 1x10^4 CE-Cohort 1Maximum Stool Grade by Stool Grade CategoryStool Grade 33 Participants
ABO809 1x10^4 CE-Cohort 1Maximum Stool Grade by Stool Grade CategoryStool Grade 10 Participants
ABO809 1x10^4 CE-Cohort 1Maximum Stool Grade by Stool Grade CategoryStool Grade >= 38 Participants
ABO809 1x10^4 CE-Cohort 1Maximum Stool Grade by Stool Grade CategoryStool Grade 53 Participants
ABO809 1x10^4 CE-Cohort 1Maximum Stool Grade by Stool Grade CategoryStool Grade 1 and 22 Participants
ABO809 1x10^6 CE-Cohort 2Maximum Stool Grade by Stool Grade CategoryStool Grade 31 Participants
ABO809 1x10^6 CE-Cohort 2Maximum Stool Grade by Stool Grade CategoryStool Grade 10 Participants
ABO809 1x10^6 CE-Cohort 2Maximum Stool Grade by Stool Grade CategoryStool Grade 22 Participants
ABO809 1x10^6 CE-Cohort 2Maximum Stool Grade by Stool Grade CategoryStool Grade 1 and 22 Participants
ABO809 1x10^6 CE-Cohort 2Maximum Stool Grade by Stool Grade CategoryStool Grade 41 Participants
ABO809 1x10^6 CE-Cohort 2Maximum Stool Grade by Stool Grade CategoryStool Grade 53 Participants
ABO809 1x10^6 CE-Cohort 2Maximum Stool Grade by Stool Grade CategoryStool Grade >= 35 Participants
ABO809 1x10^6 CE-Cohort 3Maximum Stool Grade by Stool Grade CategoryStool Grade 42 Participants
ABO809 1x10^6 CE-Cohort 3Maximum Stool Grade by Stool Grade CategoryStool Grade 23 Participants
ABO809 1x10^6 CE-Cohort 3Maximum Stool Grade by Stool Grade CategoryStool Grade >= 36 Participants
ABO809 1x10^6 CE-Cohort 3Maximum Stool Grade by Stool Grade CategoryStool Grade 53 Participants
ABO809 1x10^6 CE-Cohort 3Maximum Stool Grade by Stool Grade CategoryStool Grade 31 Participants
ABO809 1x10^6 CE-Cohort 3Maximum Stool Grade by Stool Grade CategoryStool Grade 1 and 24 Participants
ABO809 1x10^6 CE-Cohort 3Maximum Stool Grade by Stool Grade CategoryStool Grade 11 Participants
Secondary

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.

Time frame: From Day 1 up to Day 28

Population: The pharmacodynamic (PD) analysis set included all participants with available parasitological and clinical data and with no protocol deviations with relevant impact on PD data.

ArmMeasureValue (MEAN)Dispersion
ABO809 1x10^4 CE-Cohort 1Number of Diarrhea Stools Per Participant13.3 diarrheal stoolsStandard Error 4.85
ABO809 1x10^6 CE-Cohort 2Number of Diarrhea Stools Per Participant16.2 diarrheal stoolsStandard Error 7.15
ABO809 1x10^6 CE-Cohort 3Number of Diarrhea Stools Per Participant12.9 diarrheal stoolsStandard Error 3.41
Secondary

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.

Time frame: Adverse events were reported from oral administration of ABO809 up to a maximum duration of 56 days.

Population: The pharmacodynamic (PD) analysis set included all participants with available parasitological and clinical data and with no protocol deviations with relevant impact on PD data.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
ABO809 1x10^4 CE-Cohort 1Number of Participants With Adverse Events of Special Interest (AESIs)Moderate or severe dehydration2 Participants
ABO809 1x10^4 CE-Cohort 1Number of Participants With Adverse Events of Special Interest (AESIs)Persistent or recurrent cryptosporidosis0 Participants
ABO809 1x10^4 CE-Cohort 1Number of Participants With Adverse Events of Special Interest (AESIs)Extraintestinal cryptosporidiosis0 Participants
ABO809 1x10^4 CE-Cohort 1Number of Participants With Adverse Events of Special Interest (AESIs)Participants with AESI2 Participants
ABO809 1x10^4 CE-Cohort 1Number of Participants With Adverse Events of Special Interest (AESIs)Non-intestinal sequelae including eye pain or joint pain0 Participants
ABO809 1x10^4 CE-Cohort 1Number of Participants With Adverse Events of Special Interest (AESIs)Persistent cryptosporidium shedding0 Participants
ABO809 1x10^4 CE-Cohort 1Number of Participants With Adverse Events of Special Interest (AESIs)Gastroenteritis in the absence of Cryptosporidium infection0 Participants
ABO809 1x10^6 CE-Cohort 2Number of Participants With Adverse Events of Special Interest (AESIs)Extraintestinal cryptosporidiosis0 Participants
ABO809 1x10^6 CE-Cohort 2Number of Participants With Adverse Events of Special Interest (AESIs)Participants with AESI2 Participants
ABO809 1x10^6 CE-Cohort 2Number of Participants With Adverse Events of Special Interest (AESIs)Moderate or severe dehydration2 Participants
ABO809 1x10^6 CE-Cohort 2Number of Participants With Adverse Events of Special Interest (AESIs)Gastroenteritis in the absence of Cryptosporidium infection0 Participants
ABO809 1x10^6 CE-Cohort 2Number of Participants With Adverse Events of Special Interest (AESIs)Persistent or recurrent cryptosporidosis0 Participants
ABO809 1x10^6 CE-Cohort 2Number of Participants With Adverse Events of Special Interest (AESIs)Persistent cryptosporidium shedding0 Participants
ABO809 1x10^6 CE-Cohort 2Number of Participants With Adverse Events of Special Interest (AESIs)Non-intestinal sequelae including eye pain or joint pain0 Participants
ABO809 1x10^6 CE-Cohort 3Number of Participants With Adverse Events of Special Interest (AESIs)Persistent or recurrent cryptosporidosis0 Participants
ABO809 1x10^6 CE-Cohort 3Number of Participants With Adverse Events of Special Interest (AESIs)Moderate or severe dehydration2 Participants
ABO809 1x10^6 CE-Cohort 3Number of Participants With Adverse Events of Special Interest (AESIs)Non-intestinal sequelae including eye pain or joint pain0 Participants
ABO809 1x10^6 CE-Cohort 3Number of Participants With Adverse Events of Special Interest (AESIs)Persistent cryptosporidium shedding0 Participants
ABO809 1x10^6 CE-Cohort 3Number of Participants With Adverse Events of Special Interest (AESIs)Extraintestinal cryptosporidiosis0 Participants
ABO809 1x10^6 CE-Cohort 3Number of Participants With Adverse Events of Special Interest (AESIs)Gastroenteritis in the absence of Cryptosporidium infection0 Participants
ABO809 1x10^6 CE-Cohort 3Number of Participants With Adverse Events of Special Interest (AESIs)Participants with AESI2 Participants
Secondary

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.

Time frame: From Day 1 up to Day 28

Population: The pharmacodynamic (PD) analysis set included all participants with available parasitological and clinical data and with no protocol deviations with relevant impact on PD data.

ArmMeasureValue (MEAN)Dispersion
ABO809 1x10^4 CE-Cohort 1Overall Diarrheal Stool Weight1614.0 gramsStandard Deviation 1541.84
ABO809 1x10^6 CE-Cohort 2Overall Diarrheal Stool Weight2681.6 gramsStandard Deviation 2798.02
ABO809 1x10^6 CE-Cohort 3Overall Diarrheal Stool Weight2877.0 gramsStandard Deviation 1884.71
Secondary

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.

Time frame: From Day 1 up to Day 28

Population: The pharmacodynamic (PD) analysis set included all participants with available parasitological and clinical data and with no protocol deviations with relevant impact on PD data.

ArmMeasureGroupValue (NUMBER)
ABO809 1x10^4 CE-Cohort 1Percentage of Participants Showing Clinical Diarrheal Illness From Day 1 to Day 28 Post ABO809 Oral AdministrationClinical diarrheal illness up to Day 10 (inclusive)60.0 percentage of participants
ABO809 1x10^4 CE-Cohort 1Percentage of Participants Showing Clinical Diarrheal Illness From Day 1 to Day 28 Post ABO809 Oral AdministrationClinical diarrheal illness up to Day 28 (inclusive)60.0 percentage of participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants Showing Clinical Diarrheal Illness From Day 1 to Day 28 Post ABO809 Oral AdministrationClinical diarrheal illness up to Day 10 (inclusive)57.1 percentage of participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants Showing Clinical Diarrheal Illness From Day 1 to Day 28 Post ABO809 Oral AdministrationClinical diarrheal illness up to Day 28 (inclusive)57.1 percentage of participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants Showing Clinical Diarrheal Illness From Day 1 to Day 28 Post ABO809 Oral AdministrationClinical diarrheal illness up to Day 10 (inclusive)50.0 percentage of participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants Showing Clinical Diarrheal Illness From Day 1 to Day 28 Post ABO809 Oral AdministrationClinical diarrheal illness up to Day 28 (inclusive)50.0 percentage of participants
Secondary

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.

Time frame: From Day 1 up to Day 28

Population: Safety analysis set (SAF) included all participants that received one dose of ABO809 during the treatment period.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessAbdominal discomfort1 Participants
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessOccult blood1 Participants
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessFlatulence1 Participants
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessDecreased appetite2 Participants
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessVomiting1 Participants
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessHaematochezia1 Participants
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessAbdominal pain5 Participants
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessRectal tenesmus0 Participants
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessNausea3 Participants
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessDehydration2 Participants
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessOccult blood positive1 Participants
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessAbdominal tenderness0 Participants
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessAbdominal distension3 Participants
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessPyrexia1 Participants
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessDefaecation urgency4 Participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessOccult blood1 Participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessVomiting5 Participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessAbdominal discomfort0 Participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessAbdominal distension0 Participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessAbdominal pain7 Participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessAbdominal tenderness2 Participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessDefaecation urgency2 Participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessFlatulence2 Participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessHaematochezia3 Participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessNausea4 Participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessRectal tenesmus0 Participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessPyrexia2 Participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessOccult blood positive0 Participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessDecreased appetite6 Participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessDehydration2 Participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessVomiting1 Participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessDecreased appetite4 Participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessPyrexia2 Participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessDefaecation urgency4 Participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessAbdominal tenderness1 Participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessOccult blood0 Participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessAbdominal pain2 Participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessAbdominal discomfort0 Participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessOccult blood positive1 Participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessAbdominal distension1 Participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessNausea1 Participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessHaematochezia2 Participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessDehydration2 Participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessRectal tenesmus1 Participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal IllnessFlatulence2 Participants
Secondary

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.

Time frame: From 72 hours post-administration up to Day 28

Population: The pharmacodynamic (PD) analysis set included all participants with available parasitological and clinical data and with no protocol deviations with relevant impact on PD data.

ArmMeasureValue (NUMBER)
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Cryptosporidium Infection From 72 Hours to Day 28 Post ABO809 Oral Administration60.0 percentage of participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Cryptosporidium Infection From 72 Hours to Day 28 Post ABO809 Oral Administration57.1 percentage of participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Cryptosporidium Infection From 72 Hours to Day 28 Post ABO809 Oral Administration60 percentage of participants
Secondary

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.

Time frame: From 72 hours post-administration up to Day 28

Population: The pharmacodynamic (PD) analysis set included all participants with available parasitological and clinical data and with no protocol deviations with relevant impact on PD data.

ArmMeasureValue (NUMBER)
ABO809 1x10^4 CE-Cohort 1Percentage of Participants With Fecal Shedding of Cryptosporidium Parvum Oocysts60.0 percentage of participants
ABO809 1x10^6 CE-Cohort 2Percentage of Participants With Fecal Shedding of Cryptosporidium Parvum Oocysts57.1 percentage of participants
ABO809 1x10^6 CE-Cohort 3Percentage of Participants With Fecal Shedding of Cryptosporidium Parvum Oocysts60.0 percentage of participants
Secondary

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.

Time frame: From Day 1 up to Day 28

Population: The pharmacodynamic (PD) analysis set included all participants with available parasitological and clinical data and with no protocol deviations with relevant impact on PD data.

ArmMeasureValue (MEAN)Dispersion
ABO809 1x10^4 CE-Cohort 1Time to Onset of Clinical Diarrheal Illness3.3 daysStandard Deviation 1.97
ABO809 1x10^6 CE-Cohort 2Time to Onset of Clinical Diarrheal Illness3.3 daysStandard Deviation 0.96
ABO809 1x10^6 CE-Cohort 3Time to Onset of Clinical Diarrheal Illness2.8 daysStandard Deviation 0.45
Secondary

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.

Time frame: From Day 1 up to Day 10

Population: The pharmacodynamic (PD) analysis set included all participants with available parasitological and clinical data and with no protocol deviations with relevant impact on PD data. Only participants with an actual infection were included in the analysis.

ArmMeasureValue (MEAN)Dispersion
ABO809 1x10^4 CE-Cohort 1Time to Onset of Cryptosporidium Infection4.0 daysStandard Deviation 0.71
ABO809 1x10^6 CE-Cohort 2Time to Onset of Cryptosporidium Infection4.0 daysStandard Deviation 0
ABO809 1x10^6 CE-Cohort 3Time to Onset of Cryptosporidium Infection4.0 daysStandard Deviation 0
Secondary

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).

Time frame: From Day 1 up to Day 28

Population: The pharmacodynamic (PD) analysis set included all participants with available parasitological and clinical data and with no protocol deviations with relevant impact on PD data.

ArmMeasureValue (MEAN)Dispersion
ABO809 1x10^4 CE-Cohort 1Time to Resolution of Clinical Diarrheal Illness9.0 daysStandard Deviation 1.26
ABO809 1x10^6 CE-Cohort 2Time to Resolution of Clinical Diarrheal Illness9.8 daysStandard Deviation 2.22
ABO809 1x10^6 CE-Cohort 3Time to Resolution of Clinical Diarrheal Illness10.0 daysStandard Deviation 3.54
Secondary

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.

Time frame: From Day 1 up to Day 28

Population: The pharmacodynamic (PD) analysis set included all participants with available parasitological and clinical data and with no protocol deviations with relevant impact on PD data. Only participants with an actual infection were included in the analysis.

ArmMeasureValue (MEAN)Dispersion
ABO809 1x10^4 CE-Cohort 1Time to Resolution of Cryptosporidium Infection10.6 daysStandard Deviation 2.61
ABO809 1x10^6 CE-Cohort 2Time to Resolution of Cryptosporidium Infection10.8 daysStandard Deviation 2.5
ABO809 1x10^6 CE-Cohort 3Time to Resolution of Cryptosporidium Infection9.7 daysStandard Deviation 1.86

Source: ClinicalTrials.gov · Data processed: May 28, 2026