Amevive (pronounced AM-uh-veev) is a systemic biologic therapy manufactured by Biogen. It was approved in late January 2003 for the treatment of moderate to severe psoriasis in patients who are candidates for systemic therapy.

How does it work?

Psoriasis is a disease in which the immune system plays a key role. The immune system is directed in part by T cells. Amevive works by blocking and eliminating certain T cells; in psoriasis, T cells are mistakenly activated and trigger inflammation in the skin, which fuels the development of psoriasis lesions.

Amevive is given by intravenous (IV) or intramuscular (IM) injection. Treatment consists of 12 weekly injections. Patients who take the drug are required to have their T-cell counts checked weekly through a blood test. Patients are eligible for a second course after a minimum waiting period of 12 weeks. Initiation of a second course will depend on how well the patient responded and how much the symptoms improved.

Studies have also shown it may be even more effective when combined with UVB treatments, but the U.S. Food and Drug Administration (FDA) has not approved this combination of treatments.

How effective is it?

In clinical trials using IV treatments, 14 percent of patients achieved a 75 percent or greater improvement in their psoriasis. Nearly 40 percent of the patients reduced the disease by 50 percent, and 11 percent reached "clear" or "almost clear." The median duration of response for those cleared by 75 percent or greater was 3.5 months. Half of those who improved by 75 percent continued the trail on placebo; these patients continued to see 50 percent clearing for an additional 3 months.

For intramuscular injection, the median duration of remission was about two months after one course of treatment, with 21 percent of patients achieving 75 percent improvement in PASI, 42 percent reducing by 50 percent and 14 percent achieving "clear" or "almost clear."

What are the possible side effects?

In clinical trials for Amevive (all adverse effects are required to be reported), the most frequently reported side effects included:

• sore throat
• dizziness
• increased cough
• nausea
• itching
• muscle aches
• chills
• injection site pain
• injection site inflammation
• accidental injury

Studies suggest that the drug doesn't affect a person's normal immune system. However, as with other systemic medications, Amevive does suppress the immune system. It has the potential to increase the risk of infections and reactivate latent, chronic infections.

The number of certain kinds of T cells (CD4+ and CD8+ T lymphocyte) may be reduced by Amevive, based on the size of the dose. The most serious side effects are rare, but included lymphopenia (decreased number of lymphocytes circulating in the blood); malignancies; serious infections requiring hospitalization and allergic reactions. People who develop a malignancy or serious infection should discontinue treatment.

It is not yet known whether Amevive will interact with other medications or how long patients should wait after stopping their course of treatment before using other medications that suppress the immune system, such as methotrexate or Cyclosporine.

Who should avoid Amevive?

• The FDA classified Amevive as a category B treatment, meaning pregnant women should take Amevive only if clearly needed.
• Women who are nursing should consult with their physician about whether to discontinue the drug, based on the mothers' severity of psoriasis.
• Elderly patients should exercise caution with Amevive; it is not clearly known whether Amevive will affect them differently than younger patients.
• Children should not take Amevive; the safety and efficacy of Amevive has not been studied in this group.
• People with infections or low T cell counts.