Tacrolimus salvage in anti-tumor necrosis factor antibody treatment-refractory Crohn's disease

Background: Several small retrospective studies have reported encouraging response rates in patients with Crohn's disease (CD) treated with tacrolimus. Methods: We conducted a retrospective study of the use of oral tacrolimus for severe CD refractory to anti-tumor necrosis factor agents. Response was defined as a clinician's assessment of improvement after at least 7 days of treatment of one or more of the following: bowel movement frequency, fistula output, rectal bleeding, abdominal pain, extraintestinal manifestations, or well-being. Remission required all of the following: <3 stools per day, no bleeding, abdominal pain or extraintestinal manifestations, and increased well-being. Results: Twenty-four eligible patients were treated with tacrolimus for a median of 4 months. Approximately 37% were steroid dependent or steroid refractory. Response and steroid-free remission rates were 67% and 21%, respectively, and lasted for a median of 4 months. Approximately 42% of patients were able to stop steroids and 54% of patients ultimately required surgery within a median of 10 months after starting tacrolimus. Patients with mean tacrolimus trough levels of 10 to 15 ng/mL had the highest rates of response (86%) and remission (57%). Surgery seemed to be postponed in this group compared with others. An adverse event occurred in 75% of patients. Eight of these events (33%) required dose reduction and 6 (25%) led to treatment discontinuation. There were no irreversible side effects or deaths attributable to tacrolimus over a median follow-up of 56 months. Conclusions: Oral tacrolimus seems to be safe and effective in some patients with severe CD refractory to anti-tumor necrosis factor therapy, particularly at a mean trough level of 10 to 15 ng/mL.