Does co-treatment with immunosuppressors improve outcome in patients with Crohn's disease treated with adalimumab?

Background There is clear benefit from combination therapy with infliximab and immunosuppressive drugs (IS), but few data are available for adalimumab (ADA). Aim To assess the efficacy of ADA monotherapy and ADA+IS for induction and maintenance therapy in Crohn's disease. Methods Retrospective study of patients with Crohn's disease treated with ADA in Oxford, UK or Liege, Belgium. Treatment periods were divided into 6-month semesters. A combination therapy semester was defined as ADA+IS for at least 3 months; successful induction meant clinical response; a semester with flare as ADA dose escalation, starting steroids, perianal complication, or surgery; and ADA failure as ADA withdrawal for secondary loss of response or intolerance. Semesters with and without flares were compared through univariate and multivariate analysis. Results Successful induction was achieved in 171/207 (83%) patients, with no significant difference between ADA+IS and ADA monotherapy (85% vs. 82%, P = 0.50). Five hundred and sixty-two semesters in 181 patients were included for maintenance analysis. ADA+IS was not associated with fewer semesters with flare (34% vs. 35%, P = 0.96), or with ADA failure (6% vs. 8%, P = 0.43). Nevertheless, combination therapy in the first semester was associated with a lower risk of ADA failure (5% vs. 10%, P = 0.04, OR = 0.48) and combination therapy beyond 6 months was associated with fewer semesters with flares (14% vs. 36%, P = 0.02, OR = 0.31). Conclusions There may be a benefit from adalimumab+immunosuppressive drugs combination therapy during the first semester of initiating adalimumab, with a slight decrease in adalimumab failure and lower need for adalimumab dosage escalation.