Background: The use of anti-TNF antibodies has dramatically changed the management of patients with inflammatory bowel disease (IBD). While several biosimilar versions of the original drugs have already been developed, confidence regarding their efficacy and safety is not yet worldwide accepted. This study aimed to compare the efficacy and safety profile between the original infliximab (Remicade®) and a biosimilar infliximab (Remsima®) in IBD patients from a Portuguese center.
Methods: Comparative single-center retrospective study including patients with ulcerative colitis (UC) or Crohn's Disease (CD) treated with either Remicade® or Remsima®. Demographic, clinical, biochemical and endoscopic data were collected. Harvey-Bradshaw Index and Mayo Score were used to define clinical remission in CD and UC patients, respectively, according to prevailing guidelines. Endoscopic remission was defined as Simple Endoscopic Score for Crohn's Disease 0, Rutgeerts score i0-i1 or Mayo Endoscopic Subscore 0–1. Qui-square, Fisher's exact and t-student tests were used for statistical analysis.
Results: From the 90 consecutive included patients, 61 had CD and 29 had UC, from whom 60 were treated with Remicade® and 30 with Remsima®. The indications for infliximab were steroid-dependence in 36, active disease despite immunosuppressors in 22, perianal disease in 11, acute severe UC in 6, presence of several poor prognosis factors in 6, postoperative recurrence in 5, and steroid-refractoriness in 4 patients. Clinical remission was observed in 32, 54 and 64 patients, at weeks 12, 24 and 52, respectively. There were no significant differences in achieving clinical remission in any of these time points between Remicade® and Remsima® (p=0.755; p=0.361; p=0.511, respectively). From the 78 patients who had endoscopic re-evaluation 6–12 months after the initiation of infliximab, 44 (56.4%) had endoscopic remission of the disease, and no differences were found between Remicade® and Remsima® (p=0.474). The mean CRP level significantly decreased one year after infliximab (20.1 vs. 8.1 mg/L; p=0.001) and this was independent of the used agent. No differences were found between Remicade® and Remsima® regarding adverse events (7 vs. 3; p=1.000), number of patients discontinuing the drug during the follow-up (12 vs. 4; p=0.564), need of hospitalization because of disease flare (8 vs. 2; p=0.486), need of steroids during the follow-up (4 vs. 2; p=1.000), or secondary loss of response (21 vs. 8; p=0.425).
Conclusions: The biosimilar infliximab seems as effective as the original infliximab in achieving clinical and endoscopic remission in patients with IBD. No significant differences regarding adverse events, need to discontinue the drug, or loss of response were observed between Remicade® and Remsima®.