Emerging Drugs Show Promise Against Psoriasis
'Biologics' dampen the immune system and overproduction of cells
SATURDAY, Aug. 28, 2004 (HealthDayNews) -- A new generation of drugs offers hope in the ongoing search for effective psoriasis treatments.
The therapies are showing remarkable progress in quelling the disorder and bringing some semblance of normality back to the lives of sufferers.
That's the word doctors are trying to get out during Psoriasis Awareness Month, which takes place during August.
Psoriasis is a chronic illness in which the body suddenly begins overproducing skin cells. The cells pile up on the surface of the skin before they have a chance to mature, creating bright red patches covered with silvery scales.
These patches of skin cause itching, burning and stinging sensations. They most often occur on the elbows, knees, other parts of the legs, scalp, lower back, face, palms, and soles of the feet. But they can occur on skin anywhere on the body, according to the National Institutes of Health (NIH).
The disease affects between 2 percent and 2.6 percent of the United States population, or between 5.8 million and 7.5 million people.
Doctors believe the disease is linked to the immune system and is genetic in nature.
"If you have a family history, it makes it more likely you will get psoriasis," said Dr. Steven Feldman, a professor of dermatology at the Wake Forest University School of Medicine.
But beyond that, no one is sure why some people suffer from psoriasis and others do nor, or what causes the disease to start or spread.
"No one knows what triggers the onset of the disease," said Gail Zimmerman, president of the National Psoriasis Foundation. "We do know there is a genetic component and some type of environmental component that come together and trigger the disease, but we don't know what the trigger is."
Doctors generally treat psoriasis in steps based on the severity of the disease, according to the NIH. In what is known as the "1-2-3" approach, they treat the patient based on the size of the areas involved, the type of psoriasis, and the patient's response to initial treatments.
Step one involves treatment applied directly to the skin, such as a steroid cream or ointment. Step two involves light-based therapy, often involving exposure to ultraviolet rays. And step three involves medicines that affect the immune system in a way to prevent the overproduction of skin cells.
Up to now, those step-three systemic treatments involved either vitamin A derivatives or chemotherapy drugs. Both are effective, but must be limited in use or they harm the patient, Zimmerman said.
However, there is a new set of systemic drugs known as "biologics" that are proving very effective in treating psoriasis.
These drugs are made using living proteins, Zimmerman said. The proteins interfere with the way the damaged immune system is promoting overproduction of skin cells.
The biologics are injectable, and are usually self-administered at home by the patient.
The new drugs also are less intrusive on people's lives, she said. Most of them can be cut back to one injection a week once the patient begins responding to treatment. The first biologic drug approved by the U.S. Food and Drug Administration, Amevive, can cause a remission for up to seven months in which the patient needs to take no medication at all.
The only problem is that the biologic drugs don't work on every psoriasis sufferer. Zimmerman estimates between 30 percent to 40 percent of people will respond dramatically to the drugs.
"You don't know it's going to work in you until you've been on them for a few weeks, and since they are very expensive that can create a challenge," she said.
However, since the biologic drugs are relatively new, doctors also will continue to rely on and improve upon the more time-tested treatments, Feldman said.
For example, topical treatments continue to improve. "There are lotions and foams that are new that are not as messy for the patient," Feldman said.
To learn more about psoriasis and treatments, visit the National Institute of Arthritis and Musculoskeletal and Skin Diseases.