San-Juan-Rodriguez A, et al. - In this investigation, researchers assessed how the prices of existing tumor necrosis factor (TNF) inhibitors have changed as a result of new TNF inhibitors entering the market. The only TNF inhibitors approved by the US Food and Drug Administration for rheumatoid arthritis were etanercept, infliximab and adalimumab before 2009. Three therapies have since been approved by the US Food and Drug Administration: subcutaneous golimumab (April 2009), certolizumab pegol (May 2009), and intravenous golimumab (July 2013). All six agents are brand-name drugs.