Treatment Continuation in Patients Receiving Biologics or Conventional DMARD Therapy

Objective: To compare drug survival rates in patients with rheumatoid arthritis (RA) who start on a biologic agent to a control group of patients with a change in DMARD therapy after previous DMARD failure. Patients and Methods: Patients with RA enrolled in the German biologics register between May 2001 and September 2003 were included in the study. Data were available for 511 patients treated with etanercept (ETA), 343 treated with infliximab (INF), 70 treated with anakinra (ANAK), and 599 controls. Propensity scores were used to select a sub-sample of patients from the control group who were likely to be treated with biologics because of their disease severity, as well as comparable INF and ETA cases. Results: Treatment continuation after 12 months was similar for ETA (68.6%, (95% CI: 62% 75%)) and INF (65.4%, (58% 73%)) but was significantly lower for ANAK (59% (41% 77%)). Treatment continuation tended to be higher for patients treated with combinations of biologics and DMARDs than for those treated with INF or ETA alone. Patients treated with biologics were significantly more severely ill than those in the control group and had more previous DMARD failures. After adjustment for baseline differences, the continuation rates were significantly higher in patients treated with biologics than in comparable control patients treated with leflunomide (LEF) or LEF/methotrexate (MTX). Conclusion: Treatment continuation of biologics in clinical practice is lower than in randomized clinical trials but higher than in comparable controls treated with conventional DMARDs.