건선(psoriasis)에 대한 새로운 생물 약제는 재발성 피부 질환(recurring skin disease) 치료에 큰 변화를 가져올 가능성을 갖고 있는 것으로 나타났다고 medical sources가 금요일(현지시각)에 발표하였다.
Biologic Drugs Seen Helping Hard-To-Treat Psoriasis
SAN FRANCISCO (Reuters) - New biologic drugs for psoriasis have the potential to revolutionize treatment of the recurring skin disease, medical sources said on Friday.
"These drugs offer new options for patients who are in desperate need of them," said Gail Zimmerman, president of the National Psoriasis Foundation, citing new medicines made by Biogen, Amgen, Johnson & Johnson and Genentech.
Psoriasis is characterized by red, scaly patches on the skin that affects more than 4.5 million Americans. The annual market for effective psoriasis drugs could reach $5 billion.
Topical creams can help mild cases, but until recently the only systemic drugs for the skin disorder were older medicines like methotrexate that can be extremely toxic.
"Safety is the thing that biologics can bring to the table," said Dr. Kenneth Gordon, a Chicago dermatologist involved in clinical trials of the biologic drugs.
The new drugs are composed of naturally-occurring substances designed to block either immune system molecules that trigger psoriasis or the inflammatory response that leads skin cells to reproduce excessively.
The first category includes Biogen Inc.'s Amevive, approved by U.S. regulators in January as the first biologic to combat psoriasis after it was shown to reduce symptoms by at least 75 percent in 21 percent of patients after three months.
Amevive, which is given intravenously or by injection, suppresses immune system T-cells that play a central role in psoriasis. It is long-acting, but patients must be monitored due to concerns it might compromise their immune systems.
"Patients who want to stay clear of the disease for a long time may use Amevive, but others might not want to wait around and see if the disease returns. They might prefer something given continuously," Gordon said.
Genentech Inc. and Xoma Ltd.'s experimental drug Raptiva, which was submitted to the FDA in December and could be introduced late this year, is an antibody that is also engineered to inhibit T-cell activity.
Genentech said a late-stage 556-patient trial showed that weekly injections of Raptiva reduced psoriasis symptoms by at least 75 percent in 27 percent of patients after three months of treatment and by 50 percent in 59 percent of patients. Side effects included headache, chills and pain.
Genentech said it will announced promising interim results from a study of long-term treatment with Raptiva on Saturday. The company is also studying how best to "taper" treatment with Raptiva, which has been associated with severe flare-ups of psoriasis when patients abruptly stop taking the drug.
"The data suggests that Raptiva is best used as a continuous therapy for psoriasis," said Dr. Hal Barron, vice president of medical affairs at Genentech.
Jason Kantor, an analyst at W.R. Hambrecht, said each drug will address different needs, but projected that biologic drugs that block an inflammatory protein called tumor necrosis factor may prove to be more potent over time than either of the T-cell medicines.
Drugs that block the inflammatory protein include Amgen Inc.'s Enbrel, sold for several years to treat the painful joint disorder rheumatoid arthritis and psoriatic arthritis. Amgen, on Friday said a key trial found that three months of high-dose Enbrel injections helped psoriasis symptoms by at least 75 percent in 49 percent of patients, while a lower dose of the drug had the same effect in 34 percent of patients. Response rates rose after six months of treatment.
Amgen plans to file for U.S. approval of Enbrel in psoriasis later this year.
Analysts said it was unlikely that the higher dose, 50 milligrams of Enbrel twice weekly, would be approved due to toxicity and cost concerns. Enbrel is approved for rheumatoid arthritis at the lower dose used in the psoriasis trial, a regimen that costs about $10,000 to $12,000 a year.
Johnson & Johnson is also studying its rheumatoid arthritis drug Remicade against psoriasis. The intravenous drug blocks the same inflammation-causing protein as Enbrel.
In a mid-stage clinical trial of 249 patients with moderate to severe psoriasis, 88 percent treated with a higher dose of Remicade achieved at least a 75 percent improvement in symptoms after 10 weeks. At a lower dose, 72 percent of patients saw at least a 75 percent improvement.
"The Remicade data was amazing," said W.R. Hambrecht analyst Jason Kantor, adding it will likely drive off-label use of the drug for psoriasis patients.
He suggested that Remicade might have an additional advantage in that many dermatologists have set up centers to deal with patients receiving intravenous Amevive. "Doctors get paid a lot of money for in-office IV treatment. When you write a prescription you don't get paid for it," Kantor said.
출처: http://news.lycos.com/news/story.asp?section=Science&storyId=683244
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