Anti-TNF agents for the treatment of spondyloarthropathies

Etanercept in the treatment of ankylosing spondylitis: A systematic review and meta-analysis

Etanercept (ETN) has been widely applied in the treatment of ankylosing spondylitis (AS). As the use of ETN has increased, associated adverse effects have been reported frequently. Previous meta-analyses have focused on comparing the differences in clinical outcomes between ETN and placebo (PBO). The present meta-analysis evaluated randomised controlled trials (RCTs) to compare the effects of ETN and a PBO or sulfasalazine (SSZ) in patients with AS. The study population characteristics and the main results, including the Assessment in AS 20% response (ASAS 20), the Bath AS Disease Activity Index (BASDAI) and the Bath AS Functional Index (BASFI), were extracted. The pooled odds ratios (ORs) or weighted mean differences (MDs) were calculated using a fixed or random effects model. Fifteen randomised controlled trials (RCTs) involving 2,194 subjects were included. Compared with a PBO, ETN significantly improved the ASAS 20 [P<0.00001; OR, 8.25; 95% confidence interval (CI), 5.92–11.50], BASDAI (P<0.00001; MD, −18.81; 95% CI, −24.47 to −13.15) and BASFI (P<0.00001; standard MD, −0.68; 95% CI, −0.85 to −0.50). In comparison with SSZ, ETN significantly decreased the BASDAI (P<0.00001; MD, −2.40; 95% CI, −2.89 to −1.90) and C-reactive protein (CRP) levels (P<0.0001; MD, −8.01; 95% CI, −11.73 to −4.29). The most common adverse effect of ETN was an injection site reaction. This meta-analysis shows that ETN monotherapy is effective in improving physical function and reducing disease activity in patients with AS. Compared with SSZ, ETN markedly decreased the BASDAI and CRP levels. However, the efficacy of ETN in treating AS requires further evaluation by more RCTs in a larger population of patients prior to recommending ETN as a substitute for synthetic disease-modifying antirheumatic drug (DMARD) monotherapy, or combinations of synthetic DMARDs.

[Late onset spondyloarthropathy misdiagnosed as polymyalgia rheumatica]

PURPOSE

Polymyalgia rheumatica (PMR) is a frequent cause for long-term corticosteroid therapy. Management of PMR is difficult and recommendations (regarding diagnosis and treatment) from the British Society of Rheumatology have been recently published in order to avoid false diagnosis and unnecessary corticosteroid therapy. On the other hand, late onset spondyloarthropathies are difficult to diagnose due to their various presentation (peripheral and axial manifestations, usually associated with severe systemic manifestations) and the absence of validated diagnosis criteria in the elderly.

METHODS

We report on eight patients, who all of them initially responding to Bird's criteria for PMR, and whose outcome was refractory PMR with multiple flares, poor therapeutic response, with inability to taper steroids.

RESULTS

After a mean follow-up of 25 months, a diagnosis of late onset spondyloarthropathy was done in all theses patients based on clinical history, physical examination, and spine MRI. In four of the cases the use of TNFα blockers allowed to taper corticosteroid and to control the disease. Retrospectively, the diagnosis at presentation was difficult.

CONCLUSION

Among PMR patients with poor response to corticosteroids and multiple flares, the possibility of a late onset spondyloarthropathy should be discussed. There is an unmet need for validated diagnosis criteria in such patients.

Etanercept: a review of its use in the management of ankylosing spondylitis and psoriatic arthritis

Etanercept (Enbrel), a recombinant, dimeric, soluble tumour necrosis factor (TNF) receptor protein, is approved in various countries for the treatment of adult patients with ankylosing spondylitis or psoriatic arthritis. Monotherapy with subcutaneous etanercept 25mg twice weekly or 50mg once weekly was effective and generally well tolerated in patients with ankylosing spondylitis or psoriatic arthritis participating in several large, well designed clinical studies. Treatment with etanercept was more effective than placebo in reducing disease activity and improving health-related quality of life (HR-QOL) in both patient populations, and in delaying structural disease progression in patients with psoriatic arthritis. The beneficial response to etanercept achieved with shorter-term treatment was sustained in studies of up to 4 years' total duration. Randomised, well designed, head-to-head comparisons, including pharmacoeconomic analyses, with other anti-TNF biological modulators are required to accurately position etanercept and fully establish its cost effectiveness. In the meantime, etanercept is a valuable treatment option for patients with ankylosing spondylitis or psoriatic arthritis who are suitable candidates for therapy.

Adalimumab for the treatment of ankylosing spondylitis

Ankylosing spondylitis is a chronic inflammatory disease, with a prevalence of approximately 0.5%, which starts in the third decade of life. Treatment was, until recently, limited. Conventional disease-modifying drugs are not effective for the spinal manifestations, and NSAIDs and physical therapy were the standard treatment, without any other options for patients who did not respond to this treatment. Therefore, the high efficacy of the new group of TNF-blockers for the treatment of active ankylosing spondylitis represents a breakthrough for NSAID-refractory patients. Following the introduction of the two TNF-blockers, infliximab and etanercept, the fully humanized, anti-TNF monoclonal antibody adalimumab is now the third product that has been approved for the treatment of ankylosing spondylitis. Adalimumab is given subcutaneously every 2 weeks at a dose of 40 mg. In open and placebo-controlled trials, the drug was shown to be safe and effective in ankylosing spondylitis patients. Long-term treatment data of up to 2 years are now available, confirming efficacy and acceptable safety.

Etanercept: in ankylosing spondylitis

Etanercept is a dimeric fusion protein based on the p75 tumor necrosis factor (TNF) receptor. It binds to TNFalpha and blocks its biological activity. Subcutaneous etanercept is effective in the treatment of rheumatoid arthritis, psoriatic arthritis, and polyarticular-course juvenile rheumatoid arthritis. More recently, etanercept has shown efficacy in the treatment of adults with ankylosing spondylitis. In randomized, double-blind, placebo-controlled trials, subcutaneous etanercept 25mg twice weekly for 6-24 weeks significantly reduced disease activity in patients with active ankylosing spondylitis. In the largest trial, etanercept produced a response rate of 57% compared with 22% for placebo after 24 weeks (response was determined via the validated ASAS 20 response criteria developed by the Assessments in Ankylosing Spondylitis [ASAS] Working Group). Etanercept therapy significantly improved health-related quality of life in patients with ankylosing spondylitis compared with placebo. The greatest improvements in a 16-week study were seen in the domains of physical functioning, physical role, bodily pain, vitality, and social functioning. Etanercept was generally well tolerated, with few serious adverse events or treatment withdrawals. The most common adverse events were injection-site reactions and minor upper respiratory tract infections.