Does safety make a difference in selecting the right TNF antagonist?

Tumor necrosis factor (TNF) antagonists are biologic response modifiers that have significantly improved the outcomes in patients with rheumatoid arthritis (RA). At this report, safety data were collected on approximately 271,000 patients administered infliximab (as of February 2002), 121,000 patients administered etanercept (as of December 2001), and on 2400 patients who received adalimumab in trials in connection with the regulatory approval process (approval granted December 2002 in the US and September 2003 in European Union). Infliximab and etanercept have predictable and manageable safety profiles, and preliminary data suggest that the profile of adalimumab is comparable. Safety issues involving the anti-TNF agents as a class include the risk of injection-site reactions or infusion-related reactions, infection (for example, serious, opportunistic, or tubercular), malignancy, autoimmunity, and demyelinating and neurologic disorders. Injection-site and infusion-related reactions are most often easily managed and rarely lead to discontinuation of therapy. Infections can be minimized or prevented by screening and careful monitoring and follow-up; most infections respond to appropriate medical treatment. More studies are needed to evaluate the occurrence of malignancies in patients with RA to determine the potential risk posed by therapy. Antibody formation can follow the administration of any biologic agent. Although demyelinating disease has been reported with anti-TNF agents, it is not clear whether a causal relationship exists. Overall, the anti-TNF agents are well tolerated and have demonstrated a favorable benefit-to-risk profile in patients with RA.