Immunogenicity strongly impacts response to adalimumab in RA

(HealthDay)—For patients with rheumatoid arthritis (RA), long-term clinical outcomes are good with etanercept and adalimumab; but for adalimumab, treatment response is strongly dependent on the presence or absence of anti-adalimumab antibodies, according to research published in the December issue of Arthritis & Rheumatism.

Charlotte L. Krieckaert, M.D., of the Jan van Breemen Research Institute in Amsterdam, and colleagues conducted a study involving 407 patients with RA who were naive to tumor necrosis factor antagonists and received either etanercept (203 patients) or adalimumab (204 patients).

The researchers found that, of the adalimumab group, 13, 15, and 16 percent, respectively, reached sustained low disease activity, sustained minimal disease activity, and sustained American College of Rheumatology/European League Against Rheumatism remission. The corresponding rates were 16, 11, and 12 percent in the etanercept group. The best outcomes were seen for adalimumab-treated patients without anti-adalimumab antibodies; the worst outcomes were seen for those with anti-adalimumab antibodies; and intermediate outcomes were seen for etanercept-treated patients. At least sustained minimal disease activity was seen for 40 percent of patients without anti-adalimumab antibodies; 23 percent of etanercept-treated patients; and 4 percent of patients with anti-adalimumab antibodies.

"Overall, etanercept and adalimumab treatment appear similar in inducing a good long-term clinical outcome," the authors write. "However, in the case of adalimumab this is strongly dependent on the presence or absence of anti-adalimumab antibodies."

Several authors disclosed financial ties to pharmaceutical companies, including Pfizer (Wyeth) and Abbott Laboratories, both of which partially funded the study.

Copyright © 2012 HealthDay. All rights reserved.