Etrasimod for the Treatment of Ulcerative Colitis: Analysis of Infection Events from the ELEVATE UC Clinical Programme

Background and Aims: Infections are a safety concern in patients with ulcerative colitis [UC]. Etrasimod is an oral, once daily [QD], selective sphingosine 1-phosphate [S1P]_1,4,5 receptor modulator for the treatment of moderately to severely active UC. It leads to selective and reversible lymphocyte sequestration and partial peripheral lymphocyte count decrease. We report infection events from the phase 3 ELEVATE programme. Methods: Proportions, incidence rates [IRs; per 100 patient-years], and descriptive analyses of all serious, severe, herpes zoster and opportunistic infections are reported in the Pivotal UC cohort [ELEVATE UC 52 and ELEVATE UC 12]. Cox regression models evaluated potential baseline risk factors. Results: In this analysis [n = 787], proportions [IRs] of all infection events were similar for patients receiving etrasimod 2 mg QD (18.8% [41.1]) or placebo (17.7% [49.0]). Serious infections occurred in three [0.6%] and five [1.9%] patients receiving etrasimod and placebo, respectively. Two herpes zoster events were reported in each group [etrasimod: 0.4%; placebo: 0.8%], all localised and non-serious. One opportunistic infection event was reported in each group. No patient with an absolute lymphocyte count [ALC] < 0.2 × 10⁹/L reported serious/severe or opportunistic infections; no baseline risk factors were identified for such events. No deaths occurred. Conclusions: Patients receiving etrasimod demonstrated no increased risk of infection. The incidence of serious infections and herpes zoster was similar in each group. Among patients receiving etrasimod, no association between ALC < 0.5 × 10⁹/L and infection events was observed. Longer-term follow-up will further characterise the etrasimod safety profile.