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.
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).
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.
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.