Given the novel biological action of etanercept, long-term follow-up is desirable, and is required by regulatory agencies, in order to detect any unexpected adverse events.
There is no evidence comparing etanercept with other treatments in this patient group. Safety concerns and relative lack of efficacy would place ethical constraints on trials of relative effectiveness.
The effectiveness of etanercept in the treatment of other forms of JIA including psoriatic and enthesitis arthritis is unknown. International trials would be required, on account of the rarity of these conditions.
Greater health gains might be possible if etanercept was used earlier in the disease process and in less severe disease. Trials to test these hypotheses are required.