Clinical trial NCT05036668: Study of Efficacy and Safety of ABO809 in Healthy Participants
Official title: An Open Label Cryptosporidium Controlled Human Infection Model (CHIM) to Assess the Efficacy and Safety of ABO809 in Healthy Participants
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE1
Conditions: Cryptosporidium Infection, Cryptosporidiosis
Keywords: Controlled Human Infection Model, safety, tolerability, healthy volunteers, cryptosporidiosis, ABO809
Lead sponsor: Novartis
Sponsor class: INDUSTRY
First posted: 2021-09-05
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Intervention model description: Cryptosporidium controlled human infection model
Primary purpose: OTHER

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.

Eligibility criteria: 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/exclusion criteria may apply.

Primary outcomes:
measure: Percentage of Participants With Cryptosporidium Infection From 72 Hours to 10 Days Post ABO809 Oral Administration
timeFrame: At ≥72 hours post-administration (or sooner if associated with symptoms suggestive of diarrheal illness) up to Day 10 (inclusive).
Secondary outcomes:
measure: Percentage of Participants Showing Clinical Diarrheal Illness From Day 1 to Day 28 Post ABO809 Oral Administration
timeFrame: From Day 1 up to Day 28
measure: Number of Diarrhea Stools Per Participant
timeFrame: From Day 1 up to Day 28
measure: Overall Diarrheal Stool Weight
timeFrame: From Day 1 up to Day 28
measure: Maximum Stool Grade by Stool Grade Category
timeFrame: From Day 1 up to Day 28
measure: Time to Onset of Clinical Diarrheal Illness
timeFrame: From Day 1 up to Day 28
measure: Time to Resolution of Clinical Diarrheal Illness
timeFrame: From Day 1 up to Day 28
measure: Percentage of Participants With Characteristics of Clinical Signs and Symptoms Associated With Clinical Diarrheal Illness
timeFrame: From Day 1 up to Day 28
measure: Percentage of Participants With Cryptosporidium Infection From 72 Hours to Day 28 Post ABO809 Oral Administration
timeFrame: From 72 hours post-administration up to Day 28
measure: Percentage of Participants With Fecal Shedding of Cryptosporidium Parvum Oocysts
timeFrame: From 72 hours post-administration up to Day 28
measure: Time to Onset of Cryptosporidium Infection
timeFrame: From Day 1 up to Day 10
measure: Time to Resolution of Cryptosporidium Infection
timeFrame: From Day 1 up to Day 28
measure: Number of Participants With Adverse Events of Special Interest (AESIs)
timeFrame: Adverse events were reported from oral administration of ABO809 up to a maximum duration of 56 days.
Other outcomes:
Locations:
city: Baltimore
country: United States
facility: Novartis Investigative Site
state: Maryland
Study officials:
affiliation: Pharmaron CPC, Inc.
name: Mohamed Al-Ibrahim
role: PRINCIPAL_INVESTIGATOR
References: