S0768 Early and Durable Symptom Control in Patients With Moderately to Severely Active Ulcerative Colitis Treated With Etrasimod (APD334) in the Phase 2 OASIS Trial and Open Label Extension

INTRODUCTION: Etrasimod is a once daily, oral, selective sphingosine 1-phosphate receptor modulator that demonstrated efficacy in the 12-week OASIS trial (NCT02447302) in adult patients with moderately to severely active UC. Patients completing OASIS were eligible to enroll in an OLE (NCT02536404) and received etrasimod 2 mg QD for up to 52 weeks. METHODS: We evaluated the association between improvement in PROs of rectal bleeding (RB) and stool frequency (SF)4 and clinical and endoscopic response at EOT in patients receiving open label etrasimod 2 mg. We calculated least squares mean reductions in RB and SF over time in patients receiving etrasimod 2 mg (n = 49) or placebo (PBO; n = 52) in the DB study and mean reductions in RB and SF over time in patients receiving etrasimod 2 mg throughout the DB study and OLE (treat-through [TT] group, n = 31). Analyses included patients with non-missing assessments and used Mayo subscores (0–3). Endoscopic improvement was defined as asubscore ≤1; Remission was defined as endoscopic improvement + RB score ≤1, and SF score ≤1 with ≥1 point decrease from baseline; Response was defined as a decrease in the modified Mayo score (endoscopy, RB, SF) of ≥2 and ≥30%, with RB score ≤1 or ≥1 decrease from baseline. RESULTS: During the DB study, patients receiving etrasimod 2 mg vs PBO had a significantly greater reduction in RB at Wk2 (0.55 vs 0.26; P < .05) that continued through Wk12 (0.97 vs 0.63; P < .05). Etrasimod 2 mg group vs PBO had a numerically greater reduction in SF as early as Wk2 (0.33 vs 0.22; P > .05) that continued to Wk12 (0.74 vs 0.61; P > .05). At EOT, etrasimod 2 mg TT group had maintained reductions of RB or SF compared with Wk12 (change from Wk12 to EOT in RB and SF: 0.0 and 0.1). In etrasimod 2 mg TT group, reductions in RB and SF at 2 weeks were greater in patients with clinical response or clinical remission at EOT vs without (Table). Reduction in SF was greater in patients in TT group who had endoscopic improvement at EOT vs those who did not. CONCLUSION: Patients with UC who received etrasimod 2 mg in the OASIS trial had early clinical improvements seen as soon as Wk2. Early responders experienced superior clinical and endoscopic improvement at the end of the OLE compared with delayed responders.Table 1