But new hope has been placed in targeted biologic therapies, and two of these receive a big boost from studies appearing in the Nov. 20 issue of the New England Journal of Medicine.

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New drugs show promise
Both efalizumab and etanercept were shown to produce significant improvements for people suffering from moderate-to-severe cases of this incurable autoimmune disease. Both are given by injection.

Two other biologic therapies, alefacept and infliximab, are also used to treat moderate-to-severe cases of psoriasis. Alefacept is prescribed for psoriasis, while infliximab is prescribed for Crohn's disease and rheumatoid arthritis but is also prescribed for psoriasis.

Before, psoriasis was treated intermittently because the treatments were toxic, assuming that patients were offered something definitive to begin with, says Dr Alice Gottlieb, senior author of one of the studies.

Biologics provide real hope for safe and effective long-term clearing, and we've never had that, says Gottlieb, a professor of medicine and director of the clinical research centre at UMDNJ-Robert Wood Johnson Medical School in New Jersey, USA.

A step in the right direction
Dr Jeffrey Weinberg, director of the clinical research centre in the department of dermatology at St. Luke's-Roosevelt Hospital Center in New York City, adds, My feeling is that these [biologics] are a significant step forward in what we have. Certainly, the options are increasing and for the vast majority of people who take either of these two drugs, they will have good efficacy and no side effects.

That's not to say these drugs are completely without risks, Weinberg adds.

Every package insert talks about the risk of malignancy and the risk of infection, not that these have been observed in any greater number but because you are interfering with the normal function of the immune system, that's the long-term concern, Weinberg says. The drugs vary in how long they've been used. Etanercept has been used continuously in some people for six years, and we haven't seen any more malignancies.

Most of the data available, however, covers an even shorter period of time, which leaves open the question of what the long-term effects may be, he notes.

Biologics are drugs that target specific receptors on molecules or specific chemicals without affecting the entire immune system, doctors say. That means they have far fewer side effects than conventional treatments.

Psoriasis facts
Psoriasis is a genetic disease affecting the skin and/or the joints. It is a non-contagious and lifelong skin disease that takes different forms. Some people may have a spot or two, while others may have extensive coverage on their body.

Psoriatic arthritis is a form of joint disease that is strongly associated with psoriasis. This form of arthritis damages the bone and connective tissue around the joints, according to the American National Psoriasis Foundation.

Both are serious diseases, affecting more than 4,5 million people in the United States alone.

The first research study
The first new study looked at the safety and efficacy of efalizumab, which was approved by the US Food and Drug Administration (FDA) last month. This trial was sponsored by Genentech, which makes the drug.

In all, almost 600 people were randomly picked to receive either efalizumab or a placebo for 12 weeks. Depending on the results, the participants either continued the drug or the placebo for another 12 weeks.

By the 12th week, 22 percent of the participants receiving a lower dose of efalizumab and 28 percent of the participants receiving a higher dose had an improvement of 75 percent or more in the psoriasis area-and-severity index (PASI). By contrast, only five percent of the placebo group experienced an improvement. PASI is a score used to assess the extent of the skin surface area affected by psoriasis.

In the efalizumab group, improvement was seen as early as the fourth week. About three quarters (77 percent) of the participants who experienced an improvement of 75 percent or more at week 12 maintained that improvement through week 24. Even after stopping the drug at week 24, 30 percent of the participants maintained an improvement of 50 percent or more in the PASI during the next 12 weeks. By contrast, only 20 percent who were switched to a placebo at week 12 maintained the improvement for the next 12 weeks. While the drug's long-term effects remain unknown, few side effects were seen in this study.

The second research study
The second study looked at the safety and efficacy of three different regimens of etanercept, which is approved for psoriatic arthritis and several other indications but not for psoriasis. An application to use the drug for psoriasis is on file with the FDA, Gottlieb says. This study was supported by Immunex-Wyeth and Amgen, which make the drug.

A total of 652 patients received either a placebo or varying doses of etanercept for 12 weeks. Etanercept is injected under the skin.

At week 12, 14 percent of those in the low-dose group, 34 percent in the medium-dose group and 49 percent in the high-dose group had experienced an improvement of 75 percent or more in the PASI score. Only four percent in the placebo group experienced comparable improvements.

Also, Gottlieb adds, more was better, longer was better and more was faster. The longer a person took the drug, the better the response. And there was no price to pay in toxicity, the study says.

At 24 weeks the report was no increased toxicity, Gottlieb says. One got the good effects without taking on increased bad effects.

The patients themselves also reported significantly improved quality of life.

Debate to follow
Weinberg feels the drugs will make a difference in psoriasis care. His personal favourites are etanercept and efalizumab. Alefacept, the first biologic to be approved, is not as effective and has to be administered by injection in a doctor's office. Infliximab also has to be injected.

Right now, all these drugs are used for people with relatively severe cases of psoriasis.

The real debate, Weinberg says, is going to come when a mild-to-moderate patient wants one of these. - (HealthDayNews)

Read more:
New weapons against psoriasis
Psoriasis getting under your skin?

 

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