Etanercept is a biological drug which targets an inflammatory molecule called tumor necrosis factor (TNF). As such, it’s intended to damp down inflammation in diseases where this is a factor. Etanercept has shown benefit in rheumatoid arthritis and is the first biological agent to benefit people with psoriatic arthritis, a form of arthritis found in about 30% of those who have the skin condition psoriasis. Psoriatic arthritis causes joint destruction, pain and impaired quality of life. Other anti-TNF drugs such as infliximab have been shown to benefit both skin and joint inflammation in psoriasis, including psoriatic arthritis. So what is the role of etanercept? Till now it has believed that etanercept is not as effective for skin symptoms and a higher dose may also be needed in psoriatic arthritis because these patients tend to have a high body mass index.

To settle the question, researchers in Berlin and elsewhere have carried out a study comparing 50 mg of etanercept once a week with the same dose twice a week. The study covered nearly 800 patients with both psoriasis and psoriatic arthritis, who were treated with once or twice weekly etanercept for 12 weeks and then with etanercept once a week for another 12 weeks. Of those on twice weekly etanercept, 46% were clear or almost clear of skin lesions at week 12, compared to 32% of those treated once weekly. However, joint problems did not improve any more with twice weekly dosing. Etanercept, like other biological drugs, has to be given by injection and it is costly. So it is useful to know that when it comes to psoriatic arthritis, an extra dose will not improve joint pain, but may improve skin symptoms in simple psoriasis.

Source:

Sterry W et al Comparison of two etanercept regimens for treatment of psoriasis and psoriatic arthritis: PRESTA randomised double blind multicentre trial British Medical Journal 6^th February 2010; 340:300