Should you try Remicade, Enbrel, or one of the other new biologic therapies for psoriasis?
In the past few years, there has been a surge in new treatments for psoriasis. These new psoriasis treatments include biologic therapies, which use portions of the body’s natural immune system to treat a disease. Since 2003, five biologic therapies that target immune system cells and chemicals implicated in psoriasis have been approved for moderate to severe psoriasis. These drugs are Amevive (alefacept), Raptiva (ifalizumab), Enbrel (etanercept), Remicade (infliximab), and Humira (adalimumab). In addition, Embrel, Humira, and Remicade are also approved for psoriatic arthritis.
Normally, skin cells mature and are shed from the skin’s surface every 28 days. In psoriasis, however, skin cells mature every three to four days. As a result, they pile up on the skin surface and form the visible lesions of psoriasis: patches of reddish skin covered with silvery scales. It is now clear that an abnormal immune response spurs the overproduction of skin cells by activating T cells, white blood cells that normally protect the body against infection. Once activated, the T cells migrate into the skin and release cytokines -- chemicals used by the immune system to communicate messages. In psoriasis, cytokines induce skin cells to reproduce and mature at an accelerated pace.
Improved understanding of the underlying causes of psoriasis has led to new biologic therapies that specifically target immune factors implicated in psoriasis. For example, Amevive and Raptiva target the activated T cells that stimulate overproduction of skin cells, while Enbrel, Remicade, and Humira home in on cytokines. The biologic psoriasis therapies can often produce a rapid, dramatic improvement in people who have failed to respond to the older psoriasis therapies. Remicade and Humira are FDA approved for only psoriatic arthritis, but your doctor can prescribe them “off-label” for psoriasis if he or she believes they will help. Recently, a large controlled trial published in The Lancet showed that Remicade was highly effective in severe psoriasis, including difficult-to-treat nail disease. After 10 weeks, 80% of patients taking Remicade had achieved at least a 75% improvement, compared with 1% of those in the placebo group.
Although the biologics are more precisely targeted than older immunosuppressive therapies, they are not risk free. They may raise the risk of serious infections such as tuberculosis, and little is known about possible long-term side effects. They are also quite expensive, and health insurance coverage is individualized -- some plans offer full coverage, while others are very restrictive. In addition, because not everyone responds to all the biologics, a trial and-error approach is usually necessary to determine which drug is most effective in a particular patient. Yet biologic therapies have produced excellent results in cases of psoriasis that were not adequately controlled by traditional psoriasis medications. Thus, if you have moderate to severe psoriasis, you might want to ask your dermatologist whether you might benefit from one of the new biologics.
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