Trial Outcomes & Findings for The Clostridioides Difficile Trial of REC-3964 (NCT NCT06536465)

NCT ID: NCT06536465

Last Updated: 2025-11-17

Results Overview

Recurrent CDI was defined as a new episode of CDI associated with a new positive Clostridioides difficile stool toxin or requirement for additional CDI treatment during the 8-week Follow-up Period after cure of preceding CDI with initial curative treatment.

Recruitment status

TERMINATED

Study phase

PHASE2

Target enrollment

3 participants

Primary outcome timeframe

8 weeks

Results posted on

2025-11-17

Participant Flow

Due to early study termination, only 3 participants were enrolled.

Participant milestones

Participant milestones
Measure
REC-3964 250 mg
Participants received REC-3964 given at a dose 250 milligrams (mg) every 12 hours (q12h).
REC-3964 500 mg
Participants received REC-3964 given at a dose of 500 mg q12h.
Observation
Participants underwent watchful waiting. No treatment was administered.
Overall Study
STARTED
1
1
1
Overall Study
COMPLETED
1
1
1
Overall Study
NOT COMPLETED
0
0
0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Due to the small sample size, data was not reported for participant confidentiality reasons.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
REC-3964 250 mg
n=1 Participants
Participants received REC-3964 given at a dose 250 mg q12h.
REC-3964 500 mg
n=1 Participants
Participants received REC-3964 given at a dose of 500 mg q12h.
Observation
n=1 Participants
Participants underwent watchful waiting. No treatment was administered.
Total
n=3 Participants
Total of all reporting groups
Sex: Female, Male
Female
0 Participants
Due to the small sample size, data was not reported for participant confidentiality reasons.
Sex: Female, Male
Male
0 Participants
Due to the small sample size, data was not reported for participant confidentiality reasons.
Ethnicity (NIH/OMB)
Hispanic or Latino
0 Participants
Due to the small sample size, data was not reported for participant confidentiality reasons.
Ethnicity (NIH/OMB)
Not Hispanic or Latino
0 Participants
Due to the small sample size, data was not reported for participant confidentiality reasons.
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
Due to the small sample size, data was not reported for participant confidentiality reasons.
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
Due to the small sample size, data was not reported for participant confidentiality reasons.
Race (NIH/OMB)
Asian
0 Participants
Due to the small sample size, data was not reported for participant confidentiality reasons.
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
Due to the small sample size, data was not reported for participant confidentiality reasons.
Race (NIH/OMB)
Black or African American
0 Participants
Due to the small sample size, data was not reported for participant confidentiality reasons.
Race (NIH/OMB)
White
0 Participants
Due to the small sample size, data was not reported for participant confidentiality reasons.
Race (NIH/OMB)
More than one race
0 Participants
Due to the small sample size, data was not reported for participant confidentiality reasons.
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
Due to the small sample size, data was not reported for participant confidentiality reasons.

PRIMARY outcome

Timeframe: 8 weeks

Population: All randomized participants who received at least 1 dose of REC-3964 intervention or who were followed-up on in the Observational arm.

Recurrent CDI was defined as a new episode of CDI associated with a new positive Clostridioides difficile stool toxin or requirement for additional CDI treatment during the 8-week Follow-up Period after cure of preceding CDI with initial curative treatment.

Outcome measures

Outcome measures
Measure
REC-3964 250 mg
n=1 Participants
Participants received REC-3964 given at a dose 250 mg q12h.
REC-3964 500 mg
n=1 Participants
Participants received REC-3964 given at a dose of 500 mg q12h.
Observation
n=1 Participants
Participants underwent watchful waiting. No treatment was administered.
Number of Participants With Survival Without Recurrence or Requirement for Additional Clostridioides Difficile Infection (CDI) Treatment
1 Participants
1 Participants
1 Participants

PRIMARY outcome

Timeframe: Up to 8 weeks

Population: All randomized participants who received at least 1 dose of REC-3964 intervention or who were followed-up on in the Observation arm.

A TEAE was the development of an undesirable medical condition or the deterioration of a pre-existing medical condition following or during exposure to a pharmaceutical product, whether or not considered causally related to the product.

Outcome measures

Outcome measures
Measure
REC-3964 250 mg
n=1 Participants
Participants received REC-3964 given at a dose 250 mg q12h.
REC-3964 500 mg
n=1 Participants
Participants received REC-3964 given at a dose of 500 mg q12h.
Observation
n=1 Participants
Participants underwent watchful waiting. No treatment was administered.
Number of Participants With Treatment-emergent Adverse Events (TEAEs)
0 Participants
0 Participants
1 Participants

PRIMARY outcome

Timeframe: Up to 8 weeks

Population: All randomized participants who received at least 1 dose of REC-3964 intervention or who were followed-up on in the Observation arm.

A TEAE was the development of an undesirable medical condition or the deterioration of a pre-existing medical condition following or during exposure to a pharmaceutical product, whether or not considered causally related to the product. An Investigator who was qualified in medicine determined relationship to the study drug for each AE (unrelated or related). The Investigator decided whether, in his or her medical judgment, if there was a reasonable biological possibility that the event may have been caused by the study drug.

Outcome measures

Outcome measures
Measure
REC-3964 250 mg
n=1 Participants
Participants received REC-3964 given at a dose 250 mg q12h.
REC-3964 500 mg
n=1 Participants
Participants received REC-3964 given at a dose of 500 mg q12h.
Observation
n=1 Participants
Participants underwent watchful waiting. No treatment was administered.
Number of Participants With Related TEAEs
0 Participants
0 Participants
0 Participants

PRIMARY outcome

Timeframe: Up to 8 weeks

Population: All randomized participants who received at least 1 dose of REC-3964 intervention or who were followed-up on in the Observation arm.

A TEAE was the development of an undesirable medical condition or the deterioration of a pre-existing medical condition following or during exposure to a pharmaceutical product, whether or not considered causally related to the product. A Serious TEAE was defined as results in death, immediately life-threatening, requires in-participant hospitalization or prolongation of existing hospitalization, results in persistent or significant disability or incapacity in conducting activities of daily living for at least 28 days, results in a congenital abnormality or birth defect, or an important medical event that may jeopardize the participant or may require medical intervention.

Outcome measures

Outcome measures
Measure
REC-3964 250 mg
n=1 Participants
Participants received REC-3964 given at a dose 250 mg q12h.
REC-3964 500 mg
n=1 Participants
Participants received REC-3964 given at a dose of 500 mg q12h.
Observation
n=1 Participants
Participants underwent watchful waiting. No treatment was administered.
Number of Participants With Serious TEAEs
0 Participants
0 Participants
0 Participants

PRIMARY outcome

Timeframe: Up to 8 weeks

Population: All randomized participants who received at least 1 dose of REC-3964 intervention or who were followed-up on in the Observation arm.

A TEAE was the development of an undesirable medical condition or the deterioration of a pre-existing medical condition following or during exposure to a pharmaceutical product, whether or not considered causally related to the product.

Outcome measures

Outcome measures
Measure
REC-3964 250 mg
n=1 Participants
Participants received REC-3964 given at a dose 250 mg q12h.
REC-3964 500 mg
n=1 Participants
Participants received REC-3964 given at a dose of 500 mg q12h.
Observation
n=1 Participants
Participants underwent watchful waiting. No treatment was administered.
Number of Participants With TEAEs Leading to Study Drug Discontinuation
0 Participants
0 Participants
0 Participants

SECONDARY outcome

Timeframe: 8 weeks

Population: Data for this outcome measure was not summarized since there was only 1 participant in each treatment arm.

Recurrent CDI was defined as a new episode of CDI associated with a new positive Clostridioides difficile stool toxin within 8 weeks of the cessation of initial curative treatment. The number of unformed \[types 5-7 on the Bristol stool scale\] bowel movements per day were recorded by the participant in the stool diary in order to identify a new episode of diarrhea. All new episodes of diarrhea were tested for toxigenic Clostridioides difficile to confirm CDI recurrence. The rate of rCDI was defined as the proportion of participants who had the Clostridioides difficile recurrence among randomized participants.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Up to 8 weeks

Population: Data for this outcome measure could not be estimated since no recurrence events occurred during this study.

Recurrent CDI was defined as a new episode of CDI associated with a new positive Clostridioides difficile stool toxin within 8 weeks of the cessation of initial curative treatment. The number of unformed \[types 5-7 on the Bristol stool scale\] bowel movements per day were recorded by the participant in the stool diary in order to identify a new episode of diarrhea. All new episodes of diarrhea were tested for toxigenic Clostridioides difficile to confirm CDI recurrence. Time to recurrence of rCDI was to be assessed using Kaplan-Meier estimation.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Up to 8 weeks

Population: Data for this outcome measure was not assessed since no recurrence events occurred.

Recurrent CDI was defined as a new episode of CDI associated with a new positive Clostridioides difficile stool toxin within 8 weeks of the cessation of initial curative treatment. The number of unformed \[types 5-7 on the Bristol stool scale\] bowel movements per day were recorded by the participant in the stool diary in order to identify a new episode of diarrhea. All new episodes of diarrhea were tested for toxigenic Clostridioides difficile to confirm CDI recurrence. Severe CDI was defined as CDI with white blood cell count \>15,000 cells/milliliter and/or serum creatinine ≥1.5 milligram/deciliter.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Up to 8 weeks

Population: Data for this outcome measure was not assessed since no recurrence events occurred.

Recurrent CDI was defined as a new episode of CDI associated with a new positive Clostridioides difficile stool toxin within 8 weeks of the cessation of initial curative treatment. The number of unformed \[types 5-7 on the Bristol stool scale\] bowel movements per day were recorded by the participant in the stool diary in order to identify a new episode of diarrhea. All new episodes of diarrhea were tested for toxigenic Clostridioides difficile to confirm CDI recurrence.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Pre-dose, 1 hour, 3 hours, and 6 hours post morning dose on Day 1 and Day 15

Population: Data for this outcome measure was not summarized since there was only 1 participant in each treatment arm.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Pre-dose, 1 hour, 3 hours, and 6 hours post morning dose on the Day 1 and Day 15

Population: Data for this outcome measure was not summarized since there was only 1 participant in each treatment arm.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Pre-dose on Day 15

Population: Data for this outcome measure was not summarized since there was only 1 participant in each treatment arm.

Outcome measures

Outcome data not reported

Adverse Events

REC-3964 250 mg

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

REC-3964 500 mg

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Observation

Serious events: 0 serious events
Other events: 1 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure
REC-3964 250 mg
n=1 participants at risk
Participants received REC-3964 given at a dose 250 mg q12h.
REC-3964 500 mg
n=1 participants at risk
Participants received REC-3964 given at a dose of 500 mg q12h.
Observation
n=1 participants at risk
Participants underwent watchful waiting. No treatment was administered.
Gastrointestinal disorders
Constipation
0.00%
0/1 • Up to 8 weeks
All randomized participants who received at least 1 dose of REC-3964 intervention or who were followed-up on in the Observation arm. AEs occurring in participants randomized to observation were recorded up to 28 days after the participant's last day in the Observation arm.
0.00%
0/1 • Up to 8 weeks
All randomized participants who received at least 1 dose of REC-3964 intervention or who were followed-up on in the Observation arm. AEs occurring in participants randomized to observation were recorded up to 28 days after the participant's last day in the Observation arm.
100.0%
1/1 • Up to 8 weeks
All randomized participants who received at least 1 dose of REC-3964 intervention or who were followed-up on in the Observation arm. AEs occurring in participants randomized to observation were recorded up to 28 days after the participant's last day in the Observation arm.
Infections and infestations
Pharyngitis
0.00%
0/1 • Up to 8 weeks
All randomized participants who received at least 1 dose of REC-3964 intervention or who were followed-up on in the Observation arm. AEs occurring in participants randomized to observation were recorded up to 28 days after the participant's last day in the Observation arm.
0.00%
0/1 • Up to 8 weeks
All randomized participants who received at least 1 dose of REC-3964 intervention or who were followed-up on in the Observation arm. AEs occurring in participants randomized to observation were recorded up to 28 days after the participant's last day in the Observation arm.
100.0%
1/1 • Up to 8 weeks
All randomized participants who received at least 1 dose of REC-3964 intervention or who were followed-up on in the Observation arm. AEs occurring in participants randomized to observation were recorded up to 28 days after the participant's last day in the Observation arm.

Additional Information

Recursion Pharmaceuticals

Recursion Pharmaceuticals, Inc.

Phone: 385-374-1724

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place