Activated T-cells can travel to the surface of the skin and start an inflammatory reaction in which skin cells multiply much faster than normal, resulting in the formation of psoriatic plaques. Biologic drugs work by interfering with specific components of the autoimmune response and can target those chemicals involved in causing psoriasis.
Alefacept (a-LEH-fa-sep-t) (Amevive)
Alefacept is a fully human biologic agent that targets the activated T-cells, which are believed to cause the skin lesions of psoriasis. It prevents the T-cells from becoming overactive and reduces the number of activated T-cells in your body. It is the first biologic agent approved in Canada and the United States for the treatment of psoriasis.
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| How Do Biologics Work |
How Alefacept Works
Alefacept reduces the number of activated T-cells in the body's circulation and in the skin, thereby inhibiting the release of the chemicals (cytokines) that are partly responsible for causing the lesions of psoriasis. In doing so, alefacept can inhibit key steps in the overactive immune system that results in psoriasis.
How Is Alefacept Given?
Usually, alefacept is either administered at your doctor's office or at home by a nurse or it can be self-administered (after you have had appropriate training from your doctor or nurse) as a single injection into the muscle, or just under the skin, once a week for twelve weeks. Alefacept may be recommended to be used for sixteen weeks in certain patients. A blood sample is also taken on a regular basis to monitor your T-cells while on alefacept.
1. Before you start alefacept: You and your doctor will review the risks, benefits, and alternatives to alefacept. Your doctor might give you an informed consent form outlining these risks and benefits. You are entitled to review this document on your own, and with your doctor or nurse, and sign it. This document is intended to give you an additional opportunity to review the risks, benefits, and alternatives. Also, you will need some blood work done prior to starting alefacept.
2. Starting treatment with alefacept: The medication is administered by intramuscular injection. In the U.S., it is given at your doctor's office or at home by a nurse. In Canada, it can be self-administered. If you and your doctor decide that self-injection is appropriate, you will be given training by a health care professional. This training will give you information on how to prepare the drug for injection and show you the proper method for giving yourself an intramuscular injection. You should not try to inject yourself until this training has been given and you are comfortable with the process. The makers of alefacept have developed a comprehensive support program that provides a variety of services.
What Results Can You Expect from Alefacept?
With alefacept, improvements are not usually immediate but occur over several months. Many patients will continue to exhibit improvement even after the last dose of a twelve-week course. Combination therapy, such as topical steroids or phototherapy or other systemic medications (e.g., retinoids), can also be used to improve speed of onset of clearance of psoriasis.
An interesting finding in early studies with alefacept was that by reducing the number of T-cells in circulation and in the skin of patients with psoriasis, prolonged psoriasis-free periods could be attained (remission). On average, a patient who has responded well to alefacept can have a significant improvement last up to eight months or longer.
In clinical research studies, an excellent level of improvement (75 percent improvement in the score of the Psoriasis Area and Severity Index [PASI]) was seen in about 21 percent of patients, and a good response was seen in 42 percent of patients (a good response is defined as a 50 percent improvement in the PASI score) two weeks after stopping therapy.
Because improvements continue after treatment is stopped, response rates can be higher than those listed above, which are at two weeks after stopping therapy. Based on the overall response rate, 33 percent of patients had an excellent level of improvement and 57 percent had a good level of improvement. After a second twelve-week course, 43 percent had an excellent level of improvement and 69 percent had a good level. Additional courses showed further improvement.
One of the unique aspects of alefacept therapy is that the onset of activity is slower than that of many other medications. The positive results, however, can last for up to a year or longer in certain patients, which is a unique and valuable part of this therapy. In general, patients can expect to receive a response within two to three months after beginning therapy.
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| How Do Biologics Work |
If alefacept is your only therapy, be patient and try not to get frustrated - remember that it could be months before you see an improvement. However, some patients will see an improvement after several weeks. Many doctors will add topical steroids or other therapies to accelerate the onset of improvement. There have been studies combining ultraviolet light therapy (phototherapy) with alefacept and many patients have had a speedier improvement. This combination of therapies was found to be tolerable and safe in the short-term.
After the first twelve-week course, your doctor will decide if a second course is right for you. Alefacept is currently being studied for treatment of psoriatic arthritis and has demonstrated significant improvements. To find out more, you can check out How Do Biologics Work.