Drug Shows Promise Against Psoriatic Arthritis
New medication improved skin condition, lessened swelling, study finds
Current drugs such as methotrexate target a substance called tumor necrosis factor-alpha, which is produced in response to inflammation. But these drugs tend to be less effective over time, Mease said.
Brodalumab works differently. It acts against interleukin-17 receptor A, a substance found in higher levels in people with psoriatic arthritis, according to the study.
For the current phase 2 trial of brodalumab, Mease and colleagues randomly assigned 168 patients with psoriatic arthritis to a low (140 milligrams) or high dose (280 milligrams) of brodalumab, or a placebo.
The average age of the study participant was 52 years. Two-thirds of the study volunteers were women and 94 percent were white (which included Hispanics and Latinos). The average amount of time they'd had psoriatic arthritis was nine years, according to the study.
After 12 weeks, patients taking either dose of brodalumab had a greater response to treatment than those receiving placebo (37 percent and 39 percent versus 18 percent).
Moreover, 14 percent of those taking brodalumab had a 50 percent improvement in symptoms based on the American College of Rheumatology response criteria, compared with 4 percent who received the placebo, the researchers found.
Improvements were seen in both patients who had previous biologic therapy, as well as those who had not had biologic therapy in the past, the researchers noted.
After 24 weeks of treatment, 51 percent of patients taking the lower dose of brodalumab and 64 percent taking the higher dose responded to the drug. In addition, 44 percent of the patients who switched from placebo to brodalumab responded to treatment.
These responses were maintained through a year, the researchers said.
At week 12, serious side effects occurred in 3 percent of patients in the brodalumab groups and in 2 percent of those in the placebo group, they add. These included stomach pain and a skin infection called cellulitis. "This is consistent with what had been seen with other so-called biologic medications," Mease said.
Dr. Robert Kirsner is a professor and vice chairman of the department of dermatology and cutaneous surgery at the University of Miami Miller School of Medicine. "The results of this, albeit small study are extremely encouraging for patients who suffer from these conditions and for the physicians who treat them," Kirsner, who was not part of the study, said.
A phase 3 trial -- the last step before potential U.S. Food and Drug Administration approval -- is under way, testing brodalumab as a treatment for psoriasis. According to Mease, Amgen hopes to have the drug approved for psoriasis first, and then as a treatment for psoriatic arthritis.