The investigational drug brodalumab (Amgen) reduces symptoms of psoriatic arthritis, results from a phase 2 trial published in The New England Journal of Medicine indicate.
Philip J. Mease, MD, of the University of Washington in Seattle and colleagues, randomly assigned patients with active psoriatic arthritis to receive either brodalumab, a monoclonal antibody that targets the interleukin-17 receptor A (IL17RA), or placebo on day 1 and at weeks 1, 2, 4, 6, 8 and 10.
At week 12, patients who had not discontinued their participation in the study were offered open-label brodalumab (280 mg) every 2 weeks. The primary end point was 20% improvement in American College of Rheumatology response criteria (ACR 20) at week 12.
A total of 159 patients completed the double-blind phase, and 134 completed 40 weeks of the open-label extension: 57 in the brodalumab 140 mg group; 56 in the brodalumab 280 mg group; and 55 in the placebo group.
Patients in the brodalumab 140 mg and 280 mg groups had higher rates of ACR 20 compared with the placebo group (37% [P=0.03] and 39% [P=0.02], respectively, vs. 18%) at week 12.
These patients also had higher rates of ACR 50 (14% [P=0.05] and 14% [P=0.05] vs. 4%). However, ACR 70 improvement rates were not significantly higher in the brodalumab groups, according to the findings.
At week 24, ACR 20 response rates in the brodalumab 140 mg and 280 mg groups were 51% and 64%, respectively, as compared with 44% among patients who switched from placebo to open-label brodalumab. These responses were sustained through week 52, according to the study data.
Adverse events were reported by 62% and 71% of the lower-dose and higher-dose brodalumab groups and by 65% of patients receiving placebo. The most common were upper respiratory tract infection, fatigue, headache and diarrhea. Serious adverse events at week 12 occurred in 3% of patients in the brodalumab groups and in 2% of those in the placebo group.
“Brodalumab significantly improved response rates among patients with psoriatic arthritis,” the study authors concluded. “Larger studies of longer duration are necessary to assess adverse events.”
Results of the phase-3 AMAGINE-1 trial released earlier this year indicated that brodalumab is also effective in the treatment of moderate-to-severe plaque psoriasis in both treatment-naive and experienced patients.
Disclosure: The study is supported by Amgen. Brodalumab is being co-developed by Amgen and AstraZeneca/MedImmune.