Clinical Trial Intelligence

Which Endpoints Are Measured Most Often in European Inflammatory Bowel Disease Phase II & III Trials?

9 July 2026

Across 100 unique European CTIS inflammatory bowel disease trials authorized in 2024–2026, clinical remission was the dominant endpoint family, appearing in 69/100 trials and as a primary endpoint in 52/100 trials. Endoscopic response or improvement appeared in 53/100 trials, while safety endpoints appeared in 53/100 trials, making the IBD endpoint landscape a remission-plus-endoscopy model with safety as a frequent secondary or early-phase anchor.

100
Unique EU CTIS Phase II/III IBD trials
69%
Measured clinical remission in any endpoint role
52%
Used clinical remission as a primary endpoint
111
Median days from initial CTIS submission to first authorization

Clinical remission is the most frequent IBD endpoint family

Clinical remission appeared in 69/100 trials (69.0%), followed by endoscopic response/improvement and safety/tolerability, each in 53/100 trials (53.0%). Endoscopic remission/healing and symptom or PRO-2 outcomes each appeared in 47/100 trials (47.0%).

Endpoint families measured in any endpoint role, % of 100 trials
Clinical remission69.0%
Endoscopic response / improvement53.0%
Safety / tolerability53.0%
Endoscopic remission / healing47.0%
Symptoms / PRO-2 / urgency47.0%
Clinical response44.0%
Quality of life / fatigue / disability33.0%
Biomarkers / inflammatory markers29.0%
Trial-level presence; one trial can contribute to multiple endpoint families.
Interpretation

European IBD trials are not built around symptom relief alone: 53/100 included endoscopic response or improvement and 47/100 included endoscopic remission or healing, showing that objective mucosal assessment is nearly as central as clinical remission.

Primary endpoints concentrate on remission; secondary endpoints broaden into endoscopy, symptoms, safety, PROs and biomarkers

Clinical remission was primary in 52/100 trials (52.0%). As secondary endpoints, clinical remission remained common in 49/100 trials (49.0%), but endoscopic remission/healing reached 45/100 (45.0%), symptoms/PRO-2 reached 43/100 (43.0%), and safety endpoints reached 38/100 (38.0%). Exploratory or other endpoints were recorded in 1/100 trial (1.0%).

Endpoint role matrix, % of 100 trials
Endpoint family Primary Secondary Exploratory / other
Clinical remission52.0%49.0%0.0%
Endoscopic response / improvement29.0%38.0%0.0%
Symptoms / PRO-2 / urgency21.0%43.0%0.0%
Safety / tolerability17.0%38.0%0.0%
Endoscopic remission / healing4.0%45.0%0.0%
Biomarkers / inflammatory markers5.0%26.0%1.0%
Quality of life / fatigue / disability0.0%33.0%1.0%
Primary, secondary and exploratory/other classifications are based on the role assigned in the CTIS endpoint records.
Interpretation

The primary endpoint layer is narrower than the secondary layer: 52/100 trials used clinical remission as primary, while secondary endpoints expanded into endoscopic remission/healing in 45/100 trials, symptoms/PRO-2 in 43/100, safety in 38/100, quality of life in 33/100, and biomarkers in 26/100.

Ulcerative colitis and Crohn’s disease use similar remission endpoints, but Crohn’s trials lean more heavily into endoscopic response

The dataset included 49/100 ulcerative colitis trials, 37/100 Crohn’s disease trials, 12/100 mixed UC + Crohn’s or broad IBD trials, and 2/100 broad IBD/other IBD trials. Clinical remission appeared in 35/49 UC trials (71.4%) and 29/37 Crohn’s trials (78.4%), while endoscopic response/improvement appeared in 23/49 UC trials (46.9%) versus 27/37 Crohn’s trials (73.0%).

Disease groups and leading endpoint families
Disease group Trials Clinical remission Endoscopic response / improvement Safety
Ulcerative colitis4935 / 49 · 71.4%23 / 49 · 46.9%25 / 49 · 51.0%
Crohn’s disease3729 / 37 · 78.4%27 / 37 · 73.0%19 / 37 · 51.4%
Mixed UC + Crohn’s / broad IBD125 / 12 · 41.7%4 / 12 · 33.3%8 / 12 · 66.7%
Broad IBD / other IBD20 / 2 · 0.0%0 / 2 · 0.0%1 / 2 · 50.0%
Disease group assigned from CTIS disease text; mixed studies include both UC and Crohn’s disease or broad IBD labels.
Interpretation

Crohn’s disease trials were more endoscopy-forward: 27/37 Crohn’s trials included endoscopic response/improvement versus 23/49 UC trials. UC trials still relied heavily on remission, with clinical remission present in 35/49 and symptom/PRO-2 endpoints present in 26/49.

Phase III trials increase remission, steroid-free remission and quality-of-life measurement

Phase-specific analysis used 50 Phase II and 56 Phase III CTIS phase memberships. Clinical remission appeared in 31/50 Phase II memberships (62.0%) and 42/56 Phase III memberships (75.0%). Steroid-free remission increased from 3/50 Phase II memberships (6.0%) to 16/56 Phase III memberships (28.6%), while quality of life/fatigue/disability increased from 11/50 (22.0%) to 23/56 (41.1%).

Phase II versus Phase III, % of phase memberships
Endpoint family Phase II, n=50 Phase III, n=56
Clinical remission31 / 50 · 62.0%42 / 56 · 75.0%
Endoscopic response / improvement26 / 50 · 52.0%31 / 56 · 55.4%
Safety / tolerability26 / 50 · 52.0%29 / 56 · 51.8%
Endoscopic remission / healing21 / 50 · 42.0%27 / 56 · 48.2%
Quality of life /