Treatment: Biologics
Etanercept

FDA approved to treat:

• Adults with moderate to severe psoriatic arthritis. Data shows that etanercept can reduce signs and symptoms of psoriatic arthritis as well as prevent further joint damage.

• Adults with moderate to severe long-term plaque psoriasis who are candidates for phototherapy or systemic therapy.

What’s involved in taking etanercept:

• Patients give themselves an injection under the skin once or twice a week.

• Etanercept is meant to provide long-term continuous therapy.

• Screenings tests for the hepatitis B virus and latent (not causing symptoms) tuberculosis (TB) are conducted before etanercept is prescribed.

• When prescribed for psoriatic arthritis, a patient may take etanercept along with a disease-modifying, anti-rheumatic drug (DMARD), such as methotrexate.

• Patients taking are etanercept closely monitored.

Studies show that when etanercept is used to treat psoriasis and stopped, the psoriasis tends to gradually return over a 3-month period. In clinical trials, withdrawal was well-tolerated and did not cause psoriasis to flare. Reasons to stop taking etanercept may include the patient’s need for a vaccination, desire to rotate with other treatment for psoriasis, or plans for a drug “holiday.”

How etanercept works: Research shows people who have psoriasis and psoriatic arthritis have too much TNF-alpha, a chemical found in the immune system. This excess TNF-alpha causes the immune system to overreact, which leads to the inflammation that produces psoriasis lesions and the inflamed joints of psoriatic arthritis. Infliximab blocks TNF-alpha and helps lower the amount of TNF-alpha in the person’s body, which prevents the inflammation that causes psoriasis and psoriatic arthritis.

Effectiveness: Studies conducted to obtain approval from the U.S. Food and Drug Administration (FDA) have found:

• Skin clearing. In a phase II clinical study, more than half of the patients with plaque psoriasis who were taking etanercept twice weekly for 24 weeks had significant improvement. After only 12 weeks, 30% of the patients had a 75% or greater clearing. By week 24, 56% had at least 75% clearance, and 50% of these patients were clear or had minimal psoriasis. A phase III study showed similar results. At the end of 12 weeks, 34% of patients taking etanercept twice weekly experienced a 75% or greater clearing.  At a higher dose, 49% achieved a 75% or greater clearing at the end of 12 weeks.

• Sometimes ineffective. In one study, etanercept was not effective for 23% of patients with psoriasis.

• Joint improvement/skin clearing. In a 12-week study involving 60 patients with psoriasis and psoriatic arthritis, 87% of the patients receiving etanercept had significant reduction in the number of joints that were tender, painful, and/or swollen. During the 12 weeks, 26% of the patients taking etanercept also had a 75% or greater clearing of their psoriasis.

Safety and side effects: In clinical trials, etanercept is generally well-tolerated. The most common side effect is a mild to moderate injection-site reaction, such as redness, itching, pain, or swelling. These reactions usually occur during the first month and then subside.

When taken to treat rheumatoid arthritis, the medication has an excellent safety profile. Some patients have taken etanercept for more than 6 consecutive years. Serious side effects remain low over time and cumulative toxicities have not been observed.

A few serious side effects have been reported in patients who have psoriasis. These include neurological disorders and serious infections, such as tuberculosis.

References:
Gribetz, C. et al. “Clearing Psoriasis: A New Era of Optimism.” Contemporary Dermatology 2003: Vol. 1, No. 1: 1-8.

Kipnis CD et al. “Biologic treatments for psoriasis.” Journal of the American Academy of Dermatology. 2005 April;52(4):671-682.

Mease P et al. “Diagnosis and treatment of psoriatic arthritis.” Journal of the American Academy of Dermatology. 2005. January;52(1):1-19.

For an overview, visit the AAD pamphlet Psoriasis and Psoriatic Arthritis.