Etanercept is a biological response modifier (biologic) and a tumor necrosis factor (TNF) inhibitor used to treat several conditions:

Active ankylosing spondylitis
Chronic moderate-to-severe plaque psoriasis in adults
Moderate-to-severe juvenile idiopathic arthritis (JIA) in children and adolescents aged 4 to 17 who have not responded to disease-modifying antirheumatic drugs (DMARDs)
Moderate-to-severe rheumatoid arthritis in adults
Psoriatic arthritis in adults
Chronic severe plaque psoriasis in children aged 4 to 17 eligible for light therapy or other medications
This medication works by blocking TNF, a protein that contributes to pain, inflammation, and damage. Benefits may be observed as early as one week for adults and two weeks for children with JIA, with improvements in plaque psoriasis often seen within four weeks and full effects typically reached by three months.