In March 2003 the US Food and Drug Administration (FDA) approved alefacept (Amevive) for treatment of moderate to severe plaque psoriasis. Amevive, manufactured by Biogen, is an immune system suppressing drug that is given weekly by intravenous injections. The FDA approved Amevive after two randomized, double-blind, placebo-controlled studies enrolling 1,060 adults showed a significant improvement in psoriasis symptoms compared to placebo.
Psoriasis Facts
Psoriasis is a chronic skin disorder that affects 1% to 2% of the US population - approximately 5.5 million people. It occurs equally in men and women and affects mainly adults. There are several types of psoriasis, but the most common is plaque psoriasis, which affects 80% of people with psoriasis. Plaque psoriasis causes patches of dry, red skin covered with thick, silvery scales. Psoriasis can affect any site, but it occurs most commonly on the elbows, knees, scalp, lower back, face, palms, and soles of the feet.
Psoriasis Cause
Psoriasis was initially thought to be a disorder of skin cells that reproduce faster than normal and pile up on the surface of the skin. As we understand more about the immune system, it has been discovered that psoriasis is a disorder of certain white blood cells called T cells. These abnormal T cells trigger the abnormal skin turnover and inflammation seen in psoriasis.
Psoriasis Treatmets
The treatment of psoriasis has improved greatly with the understanding of the role of the immune system in causing skin abnormalities. However, treatment of psoriasis has been limited by the side-effects of the medications used. The most commonly used medications such as topical steroids, methotrexate, cyclosporine, and psoralen plus ultraviolet A (PUVA) can only be used for a limited time. After stopping these medications, symptoms generally return over a variable amount of time. Amevive is unique in that it was well-tolerated in clinical trials and induced a remission of symptoms for up to 1 year after the treatment was discontinued.
Amevive Side Effects
In clinical trials the most common side effect of Amevive treatment was transient chills which tended to occur soon after the first 1 or 2 doses and did not cause any patients to discontinue treatment. Although Amevive suppresses a portion of the immune system, the most serious infection reported during the clinical trials was pharyngitis, or the common cold. The FDA is encouraging physicians to monitor white blood cell counts during therapy and inform patients to report any signs of an infection or malignancy to their health care provider promptly while receiving treatment. The effect of Amevive on pregnancy and fetal development is not known, therefore treatment is not recommended during pregnancy.
Amevive Effectiveness
Amevive works by neutralizing the abnormal T cells, allowing the immune system to function normally. Further studies of the effectiveness of Amevive reveal that although the medication changes the way the T cells function, it does not cause a compromise of the immune system. It also produces durable clinical results that continue for prolonged periods, even after the medication is discontinued.
