Objectives: To assess the safety and efficacy of intravenous (IV) abatacept plus methotrexate (MTX) over 7 years, the longest observational period to date, in patients with established rheumatoid arthritis (RA) and an inadequate response to MTX.
Methods: Patients randomised to IV abatacept (10 or 2 mg/kg) or placebo, plus MTX, during the 1-year double-blind (DB) period of a Phase 2b study could enter the long-term extension (LTE) and receive IV abatacept 10 mg/kg monthly. Safety was assessed in patients who received ≥1 dose of abatacept; efficacy was assessed in patients originally randomised to 10 mg/kg abatacept (as-observed data).
Results: A total of 219 patients entered the LTE; 114 (52.1%) completed 7 years of treatment with abatacept plus MTX. Cumulative (DB + LTE) incidence rates of serious adverse events, serious infections, malignancies, and autoimmune events were 17.6, 3.2, 1.8, and 1.2/100 patient-years, respectively. Safety was consistent between the DB (n=220) and cumulative (n=287) periods. Improvements in American College of Rheumatology responses, disease activity, and normalisation of physical function and health-related quality of life were maintained over time. Approximately 80% of patients who achieved low disease activity or normalised modified Health Assessment Questionnaire scores at Year 1, and who remained in the study, sustained these responses in each subsequent year.
Conclusions: IV abatacept in combination with MTX demonstrated consistent safety and sustained efficacy over 7 years in MTX inadequate responders with established RA. Furthermore, some patients demonstrated a normalisation of physical function and health-related quality of life that was sustained over time.
Trial registration: ClinicalTrials.gov NCT00162266.