By Wayne Kuznar
Washington, DC—In patients with seropositive rheumatoid arthritis (RA) who have an inadequate response to a tumor necrosis factor (TNF) inhibitor, switching to rituximab (Rituxan) may be a better option than switching to another TNF inhibitor, according to data discussed by Andrea Rubbert-Roth, MD, a Rheumatologist and Senior Physician at the Klinik I für Innere Medizin at the University of Cologne, Germany.
In an observational clinical practice study, patients who had an inadequate response to a TNF inhibitor and were switched to rituximab had greater disease activity improvements and greater erythrocyte sedimentation rate (ESR) reductions compared with patients who were switched to another TNF inhibitor.
Optimal treatment strategies have not been defined for patients who have an inadequate response to, or are intolerant of, an initial TNF inhibitor. Dr Rubbert-Roth noted that 20% to 40% of patients with RA have an inadequate response to TNF inhibitor therapy.
Switching from one TNF inhibitor to another has become a standard approach. However, recent data suggest that the response to TNF inhibitors is poorer in patients with rheumatoid factor or anticyclic citrullinated protein antibodies; these patients may benefit from switching to rituximab. “Seropositive patients with RA achieve greater clinical responses to rituximab than seronegative patients,” Dr Rubbert-Roth said.
These data come from a prospective global cohort study known as SWITCH-RA, which included 728 patients who had completed 6 months of rituximab or an alternative TNF inhibitor after an inadequate response to an initial TNF inhibitor. Of these patients, 559 were seropositive and 169 were seronegative. The mean duration of previous TNF inhibitor therapy was similar between the 2 groups.
The primary end point was the 6-month change from baseline in the 28-joint Disease Activity Score (DAS28) with the addition of swollen and tender joint counts and level of C-reactive protein (DAS28–CRP-3).
In both groups of patients, at the time of the switch, the baseline DAS28–CRP-3 and DAS28–erythrocyte sedimentation rate (ESR)-3 standard deviation scores were higher in the rituximab group than in the alternative TNF inhibitor group.
At 6 months, a greater improvement was seen in DAS28–ESR-3 in seropositive patients who switched to rituximab versus patients who switched to another TNF inhibitor (1.6 vs 1.2; P = .011). No significant difference between the 2 groups was seen in the seronegative patients.
“The relative benefit of rituximab varied in seropositive patients according to the reason for interrupting the previous TNF inhibitor,” said Dr Rubbert-Roth. “Seropositive patients discontinuing a first TNF inhibitor due to inefficacy achieved significantly better responses with rituximab compared with those receiving an alternative TNF inhibitor.”
At 6 months, significantly greater decreases in the ESR were observed in seropositive patients receiving rituximab than in those receiving an alternative TNF inhibitor (–14.4 vs –7.3; P = .006); corresponding results in the seronegative patients did not reach significance.