Biomarkers of Intestinal Mucosal Healing in Crohn's Disease (P08143)

CDEIS endoscopically assesses mucosal status, by summing the following six component scores: number of bowel segments with deep ulcerations divided by number of visualized bowel segments; number of bowel segments with superficial ulcerations divided by number of visualized bowel segments; mean proportion of bowel segment surface involved by disease measured on 0-10 cm visual analog scale (VAS); mean proportion of bowel segment surface area involved by ulcerations measured on 0-10 cm VAS; presence of ulcerated stenosis anywhere; and presence of non-ulcerated stenosis anywhere. An observer who viewed procedural videotape while blinded to the allocation number and visit of the endoscopy scored the CDEIS. The sum of the six components can range from 0-44, with a higher sum indicating greater severity of mucosal inflammation. Change from baseline is defined as Week 6 minus baseline CDEIS scores, with a negative change from baseline indicating improvement.

CDEIS endoscopically assesses mucosal status, by summing the following six component scores: number of bowel segments with deep ulcerations divided by number of visualized bowel segments; number of bowel segments with superficial ulcerations divided by number of visualized bowel segments; mean proportion of bowel segment surface involved by disease measured on 0-10 cm visual analog scale (VAS); mean proportion of bowel segment surface area involved by ulcerations measured on 0-10 cm VAS; presence of ulcerated stenosis anywhere; and presence of non-ulcerated stenosis anywhere. An observer who viewed procedural videotape while blinded to the allocation number and visit of the endoscopy scored the CDEIS. The sum of the six components can range from 0-44, with a higher sum indicating greater severity of mucosal inflammation. Change from baseline is defined as Week 22 minus baseline CDEIS scores, with a negative change from baseline indicating improvement.

Concentrations of the serum biomarker hsCRP were determined at baseline and at Week 6. The change from baseline was Week 6 minus baseline.

Concentrations of the serum biomarker hsCRP were determined at baseline and at Week 22. The change from baseline was Week 22 minus baseline.

Concentrations of the stool biomarker calprotectin were determined at baseline and at Week 6. The change from baseline was Week 6 minus baseline.

Concentrations of the stool biomarker calprotectin were determined at baseline and at Week 22. The change from baseline was Week 22 minus baseline.

Concentrations of the serum biomarker lipocalin-2 were determined at baseline and at Week 6. The change from baseline was Week 6 minus baseline.

Concentrations of the serum biomarker lipocalin-2 were determined at baseline and at Week 22. The change from baseline was Week 22 minus baseline.

Concentrations of the serum biomarker REG3-A were determined at baseline and at Week 6. The change from baseline was Week 6 minus baseline.

Concentrations of the serum biomarker REG3-A were determined at baseline and at Week 22. The change from baseline was Week 22 minus baseline.

To determine R^2 a multiple linear regression analysis was conducted with the change from baseline in CDEIS score as the response variable and the baseline CDEIS score, changes from baseline in the four biomarkers serum hsCRP, serum lipocalin-2, serum Reg3-A, and stool calprotectin (their concentrations were log-transformed to make the mean function of the response more linear) at Weeks 6 and 22 as the predictor variables. CDEIS scores were provided by a blinded observer who viewed procedural videotape while blinded to the allocation number and visit of the endoscopy. The R^2 can range from 0 to 1; with higher values indicating greater predictability of the model. The primary hypothesis is that the true R^2 at weeks 6 and 22 is approximately 0.7.

Based on two measurements at baseline, the concordance correlation coefficient (CCC) was computed for each of four biomarkers, using a mixed effects model with a fixed factor for repeat measurements and a random factor for participant. The CCC can range from 0 to 1 with higher values indicating greater concordance between the 2 measurements.

The CCC of blinded (central) versus unblinded (site) scores from either CDEIS or the Simple Endoscopic Score for Crohn's Disease (SES-CD) was determined at Baseline, Week 6 and Week 22. SES-CD sums the following scores: presence and size of ulcers in five visualized bowel segments; extent of ulcerated surface in five visualized bowel segments; extent of affected surface in five visualized bowel segments; presence and type of narrowings in five visualized bowel segments; and can range from 0-56, with a higher sum indicating greater severity of mucosal inflammation. The CCC can range from 0 to 1 with higher values indicating greater concordance between the 2 measurements.