Adalimumab for Crohn's disease: long-term sustained benefit in a population-based cohort of 438 patients.

Background And Aims: Adalimumab is an effective therapy for induction and maintenance of Crohn's disease. However, results in clinical trials don't necessarily reflect daily clinical practice. Therefore, we assessed real-life long-term clinical response to adalimumab in a large population-based cohort and identified clinical parameters affecting response

Methods: All consecutive patients in North-Holland that started adalimumab between 2003 and 2011 were included, of which medical charts were reviewed. Response to induction therapy was assessed after 3months. Sustained benefit of maintenance therapy was calculated from Kaplan-Meier survival tables depicting ongoing adalimumab treatment. Regression analyses were performed to identify factors predicting response to adalimumab therapy.

Results: In total 438 Crohn's patients started adalimumab with 92.5% response to the induction phase. After 1year 83.3% showed sustained benefit of maintenance treatment, followed by 74.0% after 2years. Nevertheless, one third of patients were in steroid-free remission at the end of their follow-up. Response to induction was negatively affected by longer disease duration (OR 1.05; p<0.01) and strictures (OR 3.73; p=0.04). Increased CRP levels predicted higher rates of initial response (OR 0.31; p<0.01). Concomitant thiopurines in the first 6months of adalimumab treatment decreased the risk to fail maintenance therapy (HR 0.69, p=0.05). Previous infliximab therapy did not affect response to adalimumab, however dose escalation was more often deemed necessary (p<0.01).

Conclusion: Adalimumab was successful in the majority of patients, with 10% loss of response per subsequent year. Concomitant thiopurines might improve adalimumab maintenance treatment.