Merck Posts Encouraging Phase 3 Ulcerative Colitis Data But Roche Challenge Looms on June 23, 2026 anti-TL1A ATLAS-UC clinical remission competition etrolizumab immuno-fibrosis Inflammatory Bowel Diseases Merck MK-7240 overhangs Phase 3 Roche (company) tulisokibart Ulcerative Colitis +