More than 15,000 people are attending the annual conference of the American Academy of Dermatology (AAD), scheduled from Feb. 22-27, 2002, in New Orleans. Staff members of the National Psoriasis Foundation are attending the meeting, to gather information on the latest treatment and research advances, meet with psoriasis experts and educate physicians, nurses and corporate representatives about the psoriasis, psoriatic arthritis and the NPF.
The main psoriasis-related buzz at the meeting was about new targeted therapies being developed to treat the disease. Researchers presented key findings on several emerging drugs.
Friday, Feb. 22, 2002
Promising results revealed for new targeted psoriasis therapies
Effective, safe and long-term management of psoriasis -- that is the hope of people with psoriasis and the physicians who care for them. And new treatments in development may deliver on that front, according to Alice R. Gottlieb, M.D., Ph.D., director of the Clinical Research Center at the Robert Wood Johnson Medical School at the University of Medicine and Dentistry of New Jersey.
Dr. Gottlieb and several colleagues presented the lastest clinical trial results for emerging psoriasis and psoriatic therapies to an attentive audience of dermatologists and industry representatives.
Dr. Gottlieb highlighted new findings on two drugs, etanercept (brand name Enbrel) and infliximab (brand name Remicade), that are already on the market for various diseases but are being further investigated for psoriasis. Enbrel was approved in January 2002 for treating psoriatic arthritis and is also used for treating rheumatoid arthritis. Remicade is approved for treating rheumatoid arthritis and Crohn's disease, a inflammatory bowel condition.
The effectiveness of Remicade for treating psoriasis was first shown at last year's AAD conference, when Dr. Gottlieb unveiled exciting results. Depending on the dose, between 73 percent and 82 percent of patients saw a 75 percent improvement in their psoriasis symptoms after three treatments (Remicade is given by an intravenous infusion).
The same patients were then monitored for 26 weeks to determine how long their improvement would last. According to Dr. Gottlieb, 48 percent of patients maintained a 75 percent improvement after 26 weeks, and 55 percent of patients were still at least 50 percent better than before treatment with Remicade was started.
"Our findings to date suggest that infliximab may be a safe and effective therapy for the long-term treatment of this devastating, life-impacting disorder," Dr. Gottlieb said in a press release.
Dr. Gottlieb's study on Enbrel tracked 57 patients with psoriasis who took two doses (the drug is self-injected under the skin) per week for 24 weeks. The results were as follows:
- At 12 weeks, 70 percent of patients had a 50 percent improvement in their psoriasis, and 30 percent reached a 75 percent level of improvement.
- After 24 weeks of treatment, 77 percent of patients saw their psoriasis get at least 50 percent better, and 56 percent had a 75 percent improvement.
Both Enbrel and Remicade target tumor necrosis factor-alpha (TNF-alpha), a protein that helps regulate the body's immune response. Normally, one of the roles of TNF-alpha is to promote inflammation to fight infections. For unknown reasons, TNF-alpha is overproduced in the synovial fluid (lubricating fluid of the joints) and tissue of joints as well as the skin of people with psoriatic arthritis and psoriasis.
Thus, TNF-alpha overstimulates inflammation, which leads to painful damage of the joints and connective tissue, as well the development of lesions on the skin.
The companies that make Remicade and Enbrel are continuing to investigate the use of their drugs in treating psoriasis.
Enbrel and Remicade are two of the many "biologic response modifiers" that have been in development and testing for psoriasis and psoriatic arthritis. This new class of drugs is genetically engineered to block key interactions between cells in the immune system involved in these diseases. Other treatments for psoriasis and psoriatic arthritis, particularly those used in moderate to severe cases, can have a widespread impact on the immune system.
It is now widely accepted that psoriasis is caused by miscues in the human immune system that ultimately lead to accelerated growth of skin cells and the formation of the red, scaly lesions characteristic of the disease.
Craig Leonardi, M.D., of St. Louis, a leading clinical investigator of new treatments, discussed alefacept (brand name Amevive) and efalizumab (brand name Xanelim), which are also biolgic treatments aimed at the immune response in psoriasis. He reviewed results from phase III clinical trials of Amevive and Xanelim; read the NPF's report on the June 2001 International Psoriasis Symposium for an overview of these results.
Although they accomplish it in slightly different ways, both Xanelim and Amevive block a misstep in the immune system -- the over-activation of T cells. T cells are a type of white blood cell in the body; in psoriasis, once T cells are mistakenly activated, they can trigger other immune responses and fuel the development of psoriasis lesions.
Amevive was submitted for review to the U.S. Food and Drug Administration (FDA) in August 2001, and approval could some as soon as August 2002. Xanelim is expected to be submitted to the FDA later this year and could be available sometime in 2003.
"There are severe limitations with our current choices," Dr. Leonardi said. "But good things are coming. And the winners are going to be patients and dermatologists."
