Background: CT-P13, the first biosimilar monoclonal antibody to infliximab (IFX) has previously been confirmed to be efficacious in inducing remission in inflammatory bowel disease (IBD) patients. The aim of this study was to evaluate the long-term efficacy and safety of CT-P13 therapy in Crohn's disease (CD) and ulcerative colitis (UC) in our tertiary center.
Methods: Patients diagnosed with CD and UC, who were administered CT-P13 from June 2014 at the 1st Department of Medicine, University of Szeged, were prospectively enrolled. Clinical outcome was estimated at fixed appointments throughout the 54-week treatment period. Rates of clinical remission, response and non-response at week 14, rates of continuous clinical response (CCR), remission and loss of response at week 54 and proportion of patients remaining on CT-P13 therapy at the end of the first year were examined. CT-P13 trough levels at week 2, 6 and 14, antibody positivity at week 2, 6 and 14, CRP level at week 2, 6, 14 and 30, fecal calprotectin at week 2, 6 and 46, concomitant steroid and azathioprine therapy at the time of induction therapy and at weeks 14 and 54, previous use of anti-TNF drug, need of dose intensification and mucosal healing in UC as possible predictive factors for disease outcome at week 54 were statistically evaluated.
Results: Fifty-seven CD and 57 UC patients were included in the study of which 46 CD and 46 UC patients completed the induction therapy and 36 CD and 33 UC patients completed the 54-week treatment period. Clinical response was achieved in 44 CD patients (95.6%) and in 45 UC patients (97.8%) at week 14. Of the 36 and 33 patients who completed the 54-week treatment period, CCR were shown in 25 CD (69.4%) and 19 UC (57.6%) patients. The overall rate of loss of response was 30.4% in CD and 34.8% in UC at week 54. High CRP level at week 30 and low CT-P13 trough level at week 14 predicted to loss of response in CD. None of the examined parameters were predictive to the therapeutic outcome in UC. No difference was observed regarding the clinical outcome at week 54 between anti-TNF naïve patients and patients previously treated with an anti-TNF agent.
Conclusions: This study confirmed the long-term efficacy and safety of CT-P13 therapy IBD. However, lower response rate was shown at week 54 in UC than in CD. High CRP and low CT-P13 trough levels were predictive to treatment outcome in CD but not in UC.