May 15, 2008 -- A new biologic drug called ustekinumab may ease plaque psoriasis, two new studies show.
Ustekinumab targets two inflammatory chemicals called interleukins 12 and 23, which are involved in psoriasis.
Centocor, the drug company that makes ustekinumab, has already submitted the drug for the FDA's review. The two new studies, published in The Lancet, are ustekinumab's most recent clinical trials.
Together, the two studies included nearly 2,000 adults in the U.S., Canada, and Europe who have moderate to severe plaque psoriasis. They were randomly assigned to get a shot of ustekinumab or a placebo when the study started and an additional shot a month later.
Three months after the study started, 66% to 75% of patients taking ustekinumab had reduced their psoriasis symptoms by at least 75%. Only about 3% of those taking the placebo met that benchmark.
At that point, all of the patients got an injection of ustekinumab every three months, which eased psoriasis in most patients who had been taking the placebo. Some patients with more modest improvements benefited when they got the study's highest dose given every two months instead of every three months.
The patients had to keep taking ustekinumab to maintain their results. When they stopped, the benefits gradually faded.
Ustekinumab was generally well tolerated, but the researchers note that follow-up studies are needed to check the drug's safety in the long run.
An editorial published with the studies states that while ustekinumab compares favorably with the best available therapies for psoriasis, "many questions remain," including effectiveness in patients with psoriatic arthritis and long-term safety.
Centocor funded both of the studies; several of the researchers are Centocor employees. The editorialists note that they are conducting psoriasis studies funded by other drug companies.