Safety and Efficacy of Etrasimod (APD334) in Patients With Ulcerative Colitis

The adapted MCS was used to measure disease activity of ulcerative colitis. It consisted of 3 subscores (stool frequency, rectal bleeding, and findings of endoscopy), each of which was rated on a scale from 0 to 3, indicating normal to severe. The adapted MCS was calculated as the sum of the 3 subscores, and the overall score values ranged from 0 to 9, with a higher score indicating more severe disease. Multiple imputation method was used to handle missing data.

For determination of the endoscopic subscore of the MCS, a flexible proctosigmoidoscopy, performed with a videoendoscope following a cleansing prep (oral or rectal cathartic) was performed at screening (within 10 days prior to administration of the first dose of study drug) and the Week 12 visit. This efficacy procedure assessed endoscopic mucosal appearance. The results were rated on a scale from 0 to 3, indicating normal to severe. Endoscopic improvement was defined as Mayo endoscopic subscore (using findings of flexible proctosigmoidoscopy) of ≤1 point. Multiple imputation method was used to handle missing data.

The 2-component MCS was used to measure disease activity of ulcerative colitis. It consisted of 2 subscores (rectal bleeding and findings on endoscopy), each of which was rated on a scale from 0 to 3, indicating normal to severe. The 2-component MCS was calculated as the sum of the 2 subscores, and the overall score value ranged from 0 to 6, with a higher score indicating more severe disease. Multiple imputation method was used to handle missing data.

The TMS was used to measure disease activity of ulcerative colitis. It consisted of 4 subscores [stool frequency, rectal bleeding, findings of endoscopy (flexible proctosigmoidoscopy), and Physician's Global Assessment (PGA) score], each of which was rated on a scale from 0 to 3, indicating normal to severe. The TMS was calculated as the sum of the 4 subscores, and the overall score values ranged from 0 to 12, with a higher score indicating more severe disease. Multiple imputation method was used to handle missing data.

The trichotomous composite score of clinical remission and clinical response at Week 12 is an ordinal categorical endpoint with 3 categories (score ranging 0 to 2: score 2 for achieving both clinical remission and clinical response; 1 for only achieving clinical response, and 0 for achieving neither). Multiple imputation method was used to handle missing data.

A participant was considered to have achieved clinical remission if he/she had: 1) an endoscopy score using flexible proctosigmoidoscopy of 0 or 1 (excluding friability), 2) a rectal bleeding score of 0 or 1, and 3) a stool frequency score of 0 or 1 with a decrease of ≥1 point from baseline. Multiple imputation method was used to handle missing data.

A participant was considered to have achieved clinical response if he/she met the criteria of clinical remission defined above, or met criteria of clinical response. Clinical response was defined as a decrease in the adapted MCS of ≥ 2 points and a decrease of ≥ 30% with either a decrease of rectal bleeding of ≥ 1 or rectal bleeding score of 0 or 1.