RA response criteria help decisions about continuing TNF inhibitors

The key predictors for continuation of anti–tumor necrosis factor α treatment in patients with rheumatoid arthritis (RA) are response and achievement of a state of low disease activity. Responses seen after 6 weeks and, significantly, after 3 months help decision making.

Glfe and colleagues monitored a group of 1789 Swedes with RA who had started their first course of treatment. Response to therapy was assessed at 6 weeks and at 3 months according to American College of Rheumatology (ACR), European League Against Rheumatism (EULAR), and Simple Disease Activity Index (SDAI)/Clinical Disease Activity Index (CDAI) criteria.

The percentages of patients who responded at the lowest level (ACR20, EULAR overall and modified, and SDAI/CDAI overall criteria) were 55% to 75% at 6 weeks and 61% to 80% at 3 months. The percentages of patients who responded at a higher level (ACR50, EULAR good, SDAI/CDAI major) were 29% to 44% at 6 weeks and 34% to 57% at 3 months. Patients most likely to continue treatment were those who achieved ACR20 and ACR50 responses at 6 weeks and all levels of ACR response at 3 months.

The authors noted that little change in overall treatment response takes place between the time points.