Sustained durability and tolerability of etanercept in ankylosing spondylitis for 96 weeks

Abstract

Objective: To evaluate the continued safety and durability of clinical response in patients with ankylosing spondylitis receiving etanercept.

Methods: 277 patients who had participated in a previous randomised, double blind, placebo controlled 24 week trial were eligible to continue in this open label extension study. All patients who enrolled in the open label extension (n = 257) received subcutaneous etanercept 25 mg twice weekly for up to 72 weeks, for a combined 96 weeks of cumulative trial and open label experience. For the patients who had received etanercept for 24 weeks in the double blind trial, this represented almost 2 years of continuous etanercept treatment.

Results: Patients continuing etanercept treatment had a sustained response for almost 2 years, with 74% achieving an ASsessments in Ankylosing Spondylitis 20% (ASAS 20) response after 96 weeks of etanercept treatment. Patients who had received placebo in the preceding double blind trial had similar responses, with 70% of patients attaining an ASAS 20 response after 24 weeks of etanercept treatment and 78% achieving an ASAS 20 response after 72 weeks. Improved spinal mobility was seen in both groups. Etanercept was well tolerated in patients treated for up to 96 weeks.

Conclusion: The subcutaneous administration of twice weekly doses of etanercept provided sustained durability of response in the improvement of signs and symptoms of ankylosing spondylitis for nearly 2 years.

Figure 1

Patient disposition in an open label trial examining sustained durability and tolerability of etanercept in patients with AS. BIW, twice weekly.

Figure 2

(A) ASAS 20, ASAS 50, and ASAS 70 responses in patients who received placebo in the preceding RCT and enrolled in the open label extension study, by length of treatment. (B) Durability of response, indicated by ASAS 20, ASAS 50, and ASAS 70 responses in patients who received etanercept in the preceding RCT and enrolled in the open label extension study, by length of treatment. BIW, twice weekly; RCT, randomised clinical trial.

Figure 3

(A) Percentage of patients who attained the modified ASAS 5/6 (20% improvement in five of six criteria—patient's global assessment, pain, physical function, inflammation, a measure of spinal mobility, and an acute phase reactant—with no worsening in the remaining criterion. In addition, improvement in patient's global assessment, pain, physical function, and/or inflammation by at least 10 units). (B) Percentage of patients who attained ASAS 40 (40% improvement relative to baseline plus absolute improvement of at least 20 units in any three of four of patient's global assessment, pain, physical function, and/or inflammation, with no worsening in the remaining criterion).