Etanercept in spondyloarthopathies. Part II: safety and pharmacoeconomic issues.

Etanercept (ETN) and other anti-TNF-α agents have revolutionised the management of spondyloarthropathies (SpA). With the increasingly widespread and prolonged use of these drugs an assessment of their long-term safety is extremely important. An additional concern regarding biological agents is their higher costs compared with conventional drugs. We examined safety data regarding ETN from clinical reports, clinical trials, review articles, databases and registries. In addition, evidence was reviewed about the cost effectiveness of ETN in the treatment of patients with SpA. Our review suggests that ETN is well tolerated as long-term, continuous treatment of SpA with a favourable risk-benefit ratio maintained from 4 to 5 years. Diversity in structure and mode of action could explain some differences in the safety profile of ETN with respect to the other anti-TNF agents. In particular, ETN is less immunogenic and is less likely to induce tuberculosis re-activation than the other TNF-α antagonists. Although ETN is considerably more expensive than conventional therapy, it reduces direct and indirect costs associated to SpA by improving disease activity and quality of life. Recent pharmacoeconomic studies have demonstrated its cost-effectiveness in the treatment of SpA.