Loss of Treatment Response to Infliximab Maintenance Therapy in Crohn's Disease: A Payor Perspective

ObjectivesTo assess the incidence and economic implications of loss of treatment response among patients with Crohn's disease (CD) treated with infliximab maintenance therapy.MethodsThis was a retrospective observational study of infliximab response and costs among patients with CD using a large health-care claims database. Patients with CD receiving infliximab maintenance therapy with an initial response were selected from the Integrated Healthcare Information Services claims database (1999–2005). Patients' claim histories were used to identify patterns of response to infliximab treatment. Incidence of loss of response was estimated using Kaplan–Meier method. Annual total health-care and CD-related costs were estimated and adjusted for inflation to 2005 US dollars. Generalized linear model was used to assess the impact of loss of response on treatment costs.ResultsThe study sample included 262 patients with CD with an initial response to infliximab therapy. Within 24 months of therapy initiation, 77% of patients lost treatment response. Upward dose adjustment, a new drug therapy for CD, and CD-related emergency room or inpatient visits were the three most common indicators of loss of response. Both annual total and CD-related health-care costs for patients who lost treatment response during the first year were found to be approximately one-third higher than for those who did not lose response.ConclusionsThe majority of patients who had initial responses to infliximab maintenance treatment subsequently lost response within 2 years. Loss of response was associated with a significant increase in total health-care and CD-related costs.