Trial Outcomes & Findings for A Phase 2a Safety and Efficacy Open-Label Study of PRA023 in Subjects With Moderately to Severely Active Crohn's Disease (NCT NCT05013905)

NCT ID: NCT05013905

Last Updated: 2025-07-04

Results Overview

Number of participants who experienced treatment-emergent adverse events (AEs)

• Recruitment status: COMPLETED
• Study phase: PHASE2
• Target enrollment: 55 participants
• Primary outcome timeframe: Week 12
• Results posted on: 2025-07-04

Participant Flow

Participant milestones

Measure	PRA023 Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Overall Study STARTED	55
Overall Study COMPLETED	53
Overall Study NOT COMPLETED	2

Reasons for withdrawal

Measure	PRA023 Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Overall Study Adverse Event	1
Overall Study Lack of Efficacy	1

Baseline Characteristics

A Phase 2a Safety and Efficacy Open-Label Study of PRA023 in Subjects With Moderately to Severely Active Crohn's Disease

Baseline characteristics by cohort

Measure	PRA023 n=55 Participants Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Age, Customized Age (years) · 18-44 years	37 Participants n=5 Participants
Age, Customized Age (years) · 45-64 years	13 Participants n=5 Participants
Age, Customized Age (years) · 65+ years	5 Participants n=5 Participants
Sex: Female, Male Female	21 Participants n=5 Participants
Sex: Female, Male Male	34 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	1 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	51 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	3 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants
Race (NIH/OMB) Asian	1 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	2 Participants n=5 Participants
Race (NIH/OMB) White	48 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	4 Participants n=5 Participants
Weight	77.6 kg STANDARD_DEVIATION 20.6 • n=5 Participants
Duration of Disease (years)	10.29 years STANDARD_DEVIATION 9.27 • n=5 Participants
Baseline Crohn's disease activity index (CDAI) Score	317.9 score STANDARD_DEVIATION 67.2 • n=5 Participants
Number of Prior Exposure to Biologic Therapy Biologic Naive	16 Participants n=5 Participants
Number of Prior Exposure to Biologic Therapy 1 Prior Biologic	10 Participants n=5 Participants
Number of Prior Exposure to Biologic Therapy 2 Prior Biologics	10 Participants n=5 Participants
Number of Prior Exposure to Biologic Therapy >=3 Prior Biologics	19 Participants n=5 Participants
Baseline Simple Endoscopic Score for Crohn's Disease (SES-CD)	13.4 score STANDARD_DEVIATION 6.7 • n=5 Participants
Concomitant Immunomodulator Use	8 Participants n=5 Participants
Concomitant Oral Corticosteroid Use	22 Participants n=5 Participants

PRIMARY outcome

Timeframe: Week 12

Population: All participants who received at least 1 dose of study drug.

Number of participants who experienced treatment-emergent adverse events (AEs)

Outcome measures

Measure	PRA023 n=55 Participants Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Adverse Events	43 Participants

PRIMARY outcome

Timeframe: Week 12

Population: All participants who received at least 1 dose of study drug.

Number of participants who experienced serious adverse events (SAEs)

Outcome measures

Measure	PRA023 n=55 Participants Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Serious Adverse Events	8 Participants

PRIMARY outcome

Timeframe: Week 12

Population: All participants who received at least 1 dose of study drug.

Number of participants who experienced AEs leading to discontinuation

Outcome measures

Measure	PRA023 n=55 Participants Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Adverse Events Leading to Discontinuation	2 Participants

PRIMARY outcome

Timeframe: Week 12

Population: All participants who have been treated with PRA023 with Baseline CDAI and SES-CD scores with no important protocol deviations.

Number of participants achieving induction of endoscopic improvement (decrease in simple endoscopy score for Crohn's disease [SES-CD] ≥ 50% from Baseline)

Outcome measures

Measure	PRA023 n=50 Participants Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Endoscopic Improvement	13 Participants

SECONDARY outcome

Timeframe: Week 12

Population: All participants who have been treated with PRA023 with Baseline CDAI and SES-CD scores.

Number of participants achieving clinical remission, as defined by Crohn's disease activity index [CDAI] score < 150

Outcome measures

Measure	PRA023 n=55 Participants Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Clinical Remission	27 Participants

SECONDARY outcome

Timeframe: Week 12

Population: All participants who have been treated with PRA023 with Baseline CDAI and SES-CD scores.

Number of participants who achieved a decrease in SES-CD ≥ 50% AND reduction in CDAI ≥ 100 points from Baseline or CDAI<150

Outcome measures

Measure	PRA023 n=55 Participants Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Endoscopic and Clinical Improvement	9 Participants

SECONDARY outcome

Timeframe: Week 12

Population: All participants who have been treated with PRA023 with Baseline CDAI and SES-CD scores with at least one elevated biomarker at Baseline.

Composite response is defined as a decrease by at least 50% in hsCRP or fecal calprotectin from baseline and a reduction of either CDAI ≥ 100 points from Baseline or CDAI<150 in subjects with at least one elevated biomarker at baseline.

Outcome measures

Measure	PRA023 n=49 Participants Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Number of Participants Achieving a Composite Response	17 Participants

SECONDARY outcome

Timeframe: Week 12

Population: All participants who have been treated with PRA023 with Baseline CDAI and SES-CD scores who have elevated hsCRP values at Baseline.

Number of participants with normalization of hsCRP (as defined by hsCRP < 5 mg/L), among subjects with elevated concentrations at Baseline, at Week 12

Outcome measures

Measure	PRA023 n=36 Participants Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Normalization of C-reactive Protein	5 Participants

SECONDARY outcome

Timeframe: Week 12

Population: All participants who have been treated with PRA023 with Baseline CDAI and SES-CD scores with elevated fecal calprotectin at Baseline.

Number of participants with normalization of fecal calprotectin (fecal calprotectin < 250 ug/g), among subjects with elevated concentrations at Baseline, at Week 12

Outcome measures

Measure	PRA023 n=44 Participants Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Normalization of Fecal Calprotectin	6 Participants

SECONDARY outcome

Timeframe: Week 12

Population: All participants who have been treated with PRA023 with Baseline CDAI and SES-CD scores.

Clinical response is defined as either a reduction of either CDAI ≥ 100 points from Baseline or CDAI<150.

Outcome measures

Measure	PRA023 n=55 Participants Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Clinical Response	37 Participants

SECONDARY outcome

Timeframe: Week 12

Population: All subjects who have been treated with PRA023 with Baseline CDAI and SES-CD scores.

Number of subjects with PRO-2 remission (defined as average daily abdominal pain score ≤ 1 point and average daily stool frequency ≤ 3 points with abdominal pain and stool frequency no worse than Baseline) at Week 12.

Outcome measures

Measure	PRA023 n=55 Participants Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Two Component Patient-reported Outcome (PRO-2) Remission	27 Participants

SECONDARY outcome

Timeframe: Baseline and Week 12

Population: All participants who have been treated with PRA023 with Baseline CDAI and SES-CD scores, who have SES-CD scores at Baseline and Week 12.

Assessment of change in simple endoscopy score for Crohn's Disease (SES-CD) from Baseline. Measure Description: The SES-CD evaluates 4 endoscopic variables (ulcer size, ulcerated surface, affected surface, and narrowing, each on a scale from 0 (none) to 3 in 5 segments assessed during ileocolonoscopy (ileum, right colon, transverse colon, sigmoid and left colon, and rectum). The total score is the sum of the 4 endoscopic variable scores and ranges from 0 to 56, where higher scores indicate more severe disease.

Outcome measures

Measure	PRA023 n=51 Participants Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Change From Baseline in Simple Endoscopy Score for Crohn's Disease (SES-CD)	-2.6 score on a scale Standard Deviation 4.32

SECONDARY outcome

Timeframe: Week 12

Population: All participants who were treated with PRA023 with Baseline CDAI and SES-CD scores, and had blood samples drawn for serum concentration of PRA023

Blood samples were obtained for PK analysis of the serum concentration of PRA023 at week 12.

Outcome measures

Measure	PRA023 n=53 Participants Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Serum Concentration of PRA023 (MK-7240)	88199.1 ng/mL Standard Deviation 43811.21

SECONDARY outcome

Timeframe: Up to approximately 12 weeks

Population: All participants who were treated with PRA023 with Baseline CDAI and SES-CD scores and had blood samples collected for ADA determination

Blood samples were collected for the determination of anti-PR023 antibodies based on confirmatory assay. The number of participants with confirmed positive anti-PR023 antibodies results at any visit during the study is presented.

Outcome measures

Measure	PRA023 n=55 Participants Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Number of Participants Positive for Anti-drug Antibody (ADA)	8 Participants

SECONDARY outcome

Timeframe: Up to approximately 12 weeks

Population: All participants who were treated with PRA023 with Baseline CDAI and SES-CD scores and who were ADA positive post-baseline

Blood samples were collected for the determination of NAB. The number of participants with positive NAB results at any visit during the study is presented.

Outcome measures

Measure	PRA023 n=8 Participants Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Number of Participants With Positive Neutralizing Anti-Bodies (NAB)	8 Participants

Adverse Events

PRA023

Serious events: 8 serious events

Other events: 20 other events

Deaths: 0 deaths

Serious adverse events

Measure	PRA023 n=55 participants at risk Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Gastrointestinal disorders Crohn's Disease	7.3% 4/55 • 14 weeks Adverse event assessment occurred at every scheduled visit. An adverse event (AE) is any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related.
Gastrointestinal disorders Abdominal Pain	1.8% 1/55 • 14 weeks Adverse event assessment occurred at every scheduled visit. An adverse event (AE) is any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related.
Infections and infestations Anal Abscess	1.8% 1/55 • 14 weeks Adverse event assessment occurred at every scheduled visit. An adverse event (AE) is any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related.
Infections and infestations COVID-19 Pneumonia	1.8% 1/55 • 14 weeks Adverse event assessment occurred at every scheduled visit. An adverse event (AE) is any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related.
Metabolism and nutrition disorders Dehydration	1.8% 1/55 • 14 weeks Adverse event assessment occurred at every scheduled visit. An adverse event (AE) is any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related.

Other adverse events

Measure	PRA023 n=55 participants at risk Participants received PRA023 administered by intravenous (IV) infusion as directed by the protocol.
Infections and infestations COVID-19	10.9% 6/55 • 14 weeks Adverse event assessment occurred at every scheduled visit. An adverse event (AE) is any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related.
Infections and infestations Urinary Tract Infection	9.1% 5/55 • 14 weeks Adverse event assessment occurred at every scheduled visit. An adverse event (AE) is any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related.
General disorders Fatigue	5.5% 3/55 • 14 weeks Adverse event assessment occurred at every scheduled visit. An adverse event (AE) is any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related.
Blood and lymphatic system disorders Anaemia	7.3% 4/55 • 14 weeks Adverse event assessment occurred at every scheduled visit. An adverse event (AE) is any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related.
Infections and infestations Nasopharyngitis	5.5% 3/55 • 14 weeks Adverse event assessment occurred at every scheduled visit. An adverse event (AE) is any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related.

Additional Information

Study Director

Prometheus Biosciences, Inc.

Phone: 858-422-4300

Email: mm@prometheusbiosciences.com

Results disclosure agreements

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