P0749 Infection adverse events with tulisokibart over 50 weeks of treatment in the phase 2 Crohn’s disease APOLLO-CD trial

Abstract

Background: Biologic medications for inflammatory bowel disease are associated with increased risk of infections1 . This analysis evaluates infection adverse events (AEs) with tulisokibart, an anti-tumor necrosis factor-like cytokine 1A (TL1A) monoclonal antibody, in APOLLO-CD, a Phase 2a trial in participants with Crohn's disease (CD) in which tulisokibart was well tolerated and led to achievement of endoscopic response and other endpoints during a 12-week induction period and 36-week open-label extension (OLE) period2 Methods: Participants (>=18 years of age, moderately to severely active CD and inadequate response to conventional therapy or approved biologic therapies) received open label intravenous (IV) induction tulisokibart treatment (1000 mg at baseline then 500 mg at Weeks 2, 6, and 10). Tulisokibart induction responders were able to enter the OLE study and randomized at week 14 to receive IV tulisokibart 100 mg or 250 mg every 4 weeks. Adverse events (AEs) related to infections during the 12-week induction and up to Week 50 in the OLE are reported. Result(s): A total of 55 participants were treated in the induction period, of which 37 responders continued in the OLE (19 received tulisokibart 100 mg and 18 received tulisokibart 250 mg). During the induction period, 25 (46%) participants reported infection AEs; all were considered mild to moderate in severity, and the most common were COVID-19 and Urinary Tract Infection (Table). Two infections were serious (anal abscess and COVID-19 pneumonia), requiring hospitalization; both were deemed not drug related and resolved without treatment discontinuation. In the OLE at Week 50, 12 (63%) participants on 100 mg and 11 (61%) on 250 mg reported infection AEs, with none considered serious. The most common infection AEs were Urinary Tract Infection and COVID-19. There were two severe infection AEs (bronchitis and Clostridioides difficile) in the 250 mg dose group. No participants discontinued study treatment due to an infection AE during the entire 50 weeks of treatment (Table). No dose-dependent safety signal was observed. Conclusion(s): Tulisokibart treatment over the 12-week induction demonstrated low incidence of serious infection AEs and no apparent increased risk of infection AEs when compared with biologic treatments for CD in prior clinical trials3,4. No new infection safety signals appeared in the OLE. All infection AEs resolved, most were considered non-serious and mild to moderate in severity, and no participant discontinued treatment due to an infection AE. (Figure Presented).