Phase II drug improves PsA in more than 50 percent of patients
Editor's note: As of May 2015, Amgen has stopped developing brodalumab, due to reports of suicidal thoughts and behavior in patients taking the drug in clinical trials.
A new biologic currently in the works may effectively treat psoriatic arthritis, according to a study published this week in the New England Journal of Medicine.
Results from a Phase II clinical trial indicate that brodalumab significantly improved psoriatic arthritis symptoms in more than half the patients who took the drug for at least six months.
The placebo-controlled study included 168 patients, who were randomly assigned to take a 140-milligram (mg) or 280-mg dose of the medication, or a placebo.
Brodalumab targets interleukin-17 (IL-17), a protein, or cytokine, that triggers inflammation. IL-17 is one of the key drivers of inflammation in psoriasis. Brodalumab, delivered by injection, binds to the IL-17 receptor, which blocks the receptor from receiving the signals that promote an inflammatory response.
Although other biologics on the market target different cytokines, no treatments are currently available that specifically target IL-17.
The clinical trial, which lasted a year, evaluated the effects of brodalumab according to the American College of Rheumatology (ACR) response criteria, which measures tender and swollen joints, physical function, and pain, among other factors.
After three months of treatment, 37 percent of patients taking 140 mg of the drug, and 39 percent taking 280 mg of the drug, achieved a 20 percent improvement in disease symptoms, also known as ACR 20. Only 18 percent of patients taking a placebo achieved ACR 20.At this point in the trial, all patients began taking 280 mg doses of the drug.
At the six-month mark, 51 percent of patients who started in the 140-mg group, and 64 percent of patients who started in the 280-mg group, achieved ACR 20. In addition, 44 percent of patients who switched from placebo to brodalumab also achieved ACR 20 on the drug. These improvements were sustained through the end of the trial period, according to the study results.
Serious side effects, measured after three months, occurred in 3 percent of patients taking brodalumab. These included abdominal pain, gallbladder inflammation (cholecystitis), and cellulitis, or skin infection. After a year, 10 patients enrolled in the trial had experienced serious side effects, including heart attack, cancer, and coronary artery disease.
Investigators are currently recruiting psoriatic arthritis patients for a Phase III trial for brodalumab. Studies are also ongoing to evaluate the medication as a treatment for psoriasis.