Candidates for treatment are those who in the determination of the investigator's standard of care and the caring physician's intent are to initiate treatment with etanercept. Participants must be naïve to etanercept and naïve to other autoinjector pens or prefilled syringes and be able to self-inject. The study will consist of a 30 day screening period, and 2 treatment periods of 4 weeks duration each (one treatment period using Autoinjector A and the other using Autoinjector B). At the end of the study, participants may continue treatment with commercially available etanercept at the physician's discretion.