Phase III data for Orencia (abatacept) in rheumatoid arthritis offers insights into treatment-BMS

Results from the Phase IIIb AVERT and AMPLE trials of Orencia (abatacept), from BMS, in early moderate to severe rheumatoid arthritis (RA) patients with active disease and markers of poor prognosis, such as ACPA (anti-citrullinated protein antibody) and rheumatoid factor (RF), suggest a correlation between ACPA and treatment outcomes. It also provides further data regarding the use of Orencia plus methotrexate (MTX) in these RA patients.

One post hoc analysis of AVERT data found that in patients taking Orencia plus MTX, the proportion of patients who maintained DAS-defined remission (DAS<2.6) following drug withdrawal was higher in patients with disease duration of three months or less (33%), compared with patients with longer disease duration (>3 to ?6 months, 14.7%; >6 months, 10.2%). Shorter disease duration was also associated with a faster onset of clinical response.

Additionally, an exploratory analysis of AMPLE data suggests higher serum ACPA levels at baseline correlated with a better clinical response from Orencia plus MTX compared to adalimumab plus MTX. When patients were divided into quartiles based on baseline ACPA titer, significant differences in response were observed between patients in the highest titer quartile (Q4) versus Q1�3 for DAS28 (CRP) and HAQ-DI (p=0.003 and p=0.021, respectively) in the Orencia treated arm, while, Q4 versus Q1�3 treatment differences were not significant with adalimumab (p=0.358 and p=0.735). This data should provide additional understanding into the use of Orencia plus methotrexate in patients with early, active, moderate to severe RA. Data were presented in three separate posters during the European League Against Rheumatism Annual Congress.