S823 The Impact of Treatment Switch Among Prevalent Patients With Crohn's Disease Treated With a First-Line Biologic: A U.S. Retrospective Claims Database Study. (October 2022) - Gagnon-Sanschagrin, Patrick; Davidson, Mikhaïl; Guérin, Annie; Willey, Cynthia; Kachroo, Sumesh; Hoops, Timothy; Naessens, Dominik; Cloutier, Martin