MRCP2-1752

A 32-year-old woman with a 10-year history of severe ileo-colonic Crohn’s disease is admitted for evaluation and treatment of a severe flare-up of her condition. She is experiencing severe lower abdominal pain, diarrhea, weight loss, and fatigue, and has recently developed a vesico-colic fistula. She has been taking mycophenolate mofetil (MMF) which had been effective in controlling her symptoms for the past few months, but is now losing its effectiveness. What is the most appropriate next step in steroid-sparing therapy for this patient?