Background: The aim of this study was to assess the long-term usage patterns and safety of infliximab in patients with Crohn's disease in clinical practice.
Methods: The medical records of 492 unselected patients treated with infliximab at Mayo Clinic were reviewed and abstracted for demographic features, usage patterns, and adverse events.
Results: The patients received a median of seven infusions and had a median follow-up of 6.3 years. Twenty-eight patients (6 %) were lost to follow-up, 63 patients (13 %) had no clinical benefit, and 401 patients (80 %) had partial or complete response. Of the responding patients, 114 (28 %) received induction treatment only, 167 (42 %) received initial episodic treatment (62 switched to scheduled maintenance treatment of whom 32 [42 %] were still on infliximab at last follow-up), and 120 (30 %) received scheduled maintenance treatment (56 patients [32 %] still on infliximab at last follow-up). Three patients (0.6 %) developed septic shock and six patients (1.5 %) developed septicemia. One patient (0.2 %) developed Mycobacterium avium complex. Histoplasmosis occurred in three patients (0.6 %). The cumulative 10-year probability for developing cancer after infliximab was 9 %. Among the 31 patients developing malignancies (6 %), 15 (3 %) had solid tumors, 11 (2 %) had melanoma and non-melanoma skin cancers, three (0.6 %) had lymphomas (0.6 %), and two (0.4 %) had leukemia. Overall 10-year survival after the final course of infliximab was 94 %. Among the 28 deaths (6 %), nine occurred within 12 weeks of an infliximab infusion-two of these deaths were due to infections.
Conclusions: Long-term follow-up of patients with Crohn's disease who were treated with infliximab initially between 1998 and 2002 showed persistence of therapy (due to clinical benefit) and an acceptable safety profile, despite the fact that less than one-third initially received three-dose induction followed by scheduled maintenance therapy. Infections and malignancy occurred at rates similar to those previously reported.