COPENHAGEN — Etanercept was better than sulfasalazine for improving clinical symptoms in patients with ankylosing spondylitis, regardless of whether they had peripheral joint involvement.
“These findings support the role of etanercept as a key therapy for the management of subjects with AS [ankylosing spondylitis] regardless of peripheral joint involvement,” Dr. Jürgen Braun and his associates reported in a poster at the annual European Congress of Rheumatology.
The results help further solidify the role of tumor necrosis factor (TNF) inhibitors as the standard of care for treating AS, Dr. Braun said in an interview. Until recently, when TNF inhibitors became established as prime agents for treating AS, sulfasalazine had been the most widely used drug in this disorder, said Dr. Braun, director of the regional rheumatology center at St. Josefs Hospital in Herne, Germany.
The new analysis used data collected from 566 patients with active AS who had failed treatment with a NSAID. The study randomized them to either etanercept (Enbrel) 50 mg subcutaneously once weekly or up to 3 g sulfasalazine daily. The study's primary end point was the percentage of patients having a 20% or better improvement from baseline in their disease state, as measured by ASAS (Assessment of AS International Society) 20 criteria, after 16 weeks of treatment. The study was done at several centers in 15 European countries and in China.
The study was sponsored by Wyeth, the company that markets etanercept. Dr. Braun said that he was on the speakers bureau of and received grants from “all companies that sell biologics in the field of SpA.” His coauthors all served as speakers for, received grants from, or were employees of Wyeth.
Dr. Braun and his associates reported results for the entire group of 566 patients last October at the annual meeting of the American College of Rheumatology.
An ASAS 20 response occurred in 76% of 379 patients treated with etanercept and in 51% of 187 patients treated with sulfasalazine, a statistically significant difference (Arthritis Rheum. 2008;58:S415).
In their most recent report on these data at the EULAR Congress, the researchers updated the ASAS 20 response in sulfasalazine-treated patients to 53%, still significantly less than the 76% rate in those treated with etanercept.
Further assessment in a post hoc analysis divided the patients into a group of 374 without swollen peripheral joints, and a group of 181 with at least one swollen peripheral joint. (Joint status wasn't available for the other 11 patients in the study.)
Among the patients with peripheral joint swelling, an ASAS 20 response was still significantly more common in those treated with etanercept (69%) than in those treated with sulfasalazine (50%), they reported in their poster. A significant difference in favor of etanercept also appeared in the subgroup of patients without peripheral joint swelling.
Etanercept was significantly better than sulfasalazine among both subgroups for all of the other efficacy measures reported, including achievement of partial remission, and improvement of several of the Bath AS clinical measures, including the Bath AS Disease Severity Index.
The emergence of etanercept and other TNF inhibitors as substantially more effective than sulfasalazine for treating AS has been a major advance in AS treatment. Although sulfasalazine has been, until recently, the most commonly used drug, it never achieved an anchor role for AS, as methotrexate has for treating rheumatoid arthritis, Dr. Braun said in the interview. The ASAS is now in the process of updating its AS treatment recommendations, which the group last issued in 2005. The updated recommendations should be released by the end of this year, Dr. Braun said.
Figures reported at the EULAR Congress show 76% of patients responded to etanercept, 53% to sulfasalazine.
Source Dr. Braun