Feb. 22, 2005 (New Orleans) - As many as 4.5 million Americans suffer from psoriasis, a chronic disease that can be physically and emotionally disabling, but in recent years the arrival of a new class of drugs called biologics has revolutionized psoriasis treatment, and new research suggests that these benefits are durable.
Biologics target the immune system and block the inflammation seen in psoriasis. Many biologics have been FDA approved for the treatment of psoriasis, including Embrel, Amevive, and Raptiva. Others have been shown to be effective in treating psoriasis and may receive FDA approval in the future, including Remicade and Humira.
"Biologics are designed to provide select, immunologically directed intervention within the body to target psoriasis-causing reactions, controlling the condition and helping to prevent flare-ups," said Jeffrey Weinberg, MD, assistant clinical professor of dermatology at Columbia University in New York.
"Biologics also are proving to have fewer side effects than traditional psoriasis therapies, meaning patients can find relief for longer periods of time without having to switch treatments," he said.
Weinberg discussed these therapies at a news conference at the annual meeting of the American Academy of Dermatology.
Alice B. Gottlieb, MD, a professor at the University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School in New Brunswick, presented her study on the treatment of patients with moderate to severe psoriasis. Her study showed that up to 30 months of treatment with Raptiva was safe and effective.
Patients who improved by at least 50% with three months of treatment were able to enroll in a maintenance therapy study and receive an additional 30 months of treatment. These patients sustained an improvement for up to three years. Genentech Inc. -- the maker of Raptiva -- funded this study.
When asked if three months should be a standard trial period for a biologic, Gottlieb tells WebMD, "With these drugs we generally say that longer is better. With this drug, six months is needed. But it is difficult to get a patient to stay on a drug for six months if he doesn't see results."
Because biologic treatments interfere with the body's own immune system, there is some concern that they would interfere with the body's ability to fight infections or would increase the risk of cancer. Gottlieb says the results of the three-year study may ease some of that concern. While there was an increase in the number of colds reported by patients who received Raptiva, there was no increase in cancers.
Humira Looks Promising
Richard Langley, MD, research director in dermatology at Dalhousie University in Halifax, Nova Scotia, presented data from a study of 60 weeks of treatment with Humira. Humira is not yet approved for treatment of psoriasis.
Patients with moderate to severe psoriasis received either 80 mg of Humira at the beginning and 40 mg every other week, two weeks of 80 mg of Humira followed by 40 mg every week, or a placebo. Most patients were white males, and the average age was 44.
After 24 weeks of treatment with Humira, 67% of patients who received treatment every other week and 77% of patients who received weekly treatment achieved a 75% improvement in severity.
Moreover, most of the skin was free of psoriasis for more than 75% of patients.
Another Humira study showed that the drug is also effective for psoriatic arthritis. Both studies were sponsored by Abbott Laboratories, which makes Humira.
In this study, 67% of patients treated with Humira were "clear" or "almost clear" after 24 weeks compared with 10% of patients treated with a placebo, says Philip Mease, MD, clinical professor at the University of Washington in Seattle.
Speaking at the news conference, Weinberg said there is little doubt that biologics are rapidly becoming the drugs of choice for psoriasis. But many questions still need to be answered, including better methods for identifying patients who will respond to the drugs, as well as more evidence to support selection of a particular biologic.
The final word, he says, is still to come. Meanwhile, "The data on these drugs is promising. As more and more research is done, dermatologists can help more psoriasis patients find the best therapy for their condition," Weinberg said.