Brodalumab binds to the interleukin-17 (IL-17) receptor and reduces inflammatory signalling by blocking the binding of several IL-17 ligands to the receptor.
According to the company, the IL-17 pathway plays a major role in inducing and promoting inflammatory disease processes.
The Phase II trial showed that treatment with brodalumab improved signs and clinical symptoms associated with the disease, including tender and swollen joints, at 12 weeks as measured by a 20% improvement in the American College of Rheumatology response criteria (ACR20).
In the randomised, double-blind, placebo-controlled trial, patients with active psoriatic arthritis were given brodalumab (140 or 280mg subcutaneously) or placebo at day one and weeks one, two, four, six, eight, and ten.
The company said that at week 12, patients were offered open-label brodalumab 280mg every two weeks.
Amgen research and development executive vice-president Sean Harper said: "This encouraging psoriatic arthritis data showing that patients not only experienced improvements in clinical symptoms at week 12, but that those improvements continued over time and were sustained, was the basis for our decision to continue development of this molecule as a potential treatment for the many people who are looking to better control their disease."
Primary endpoint was also achieved in the trial with both doses of brodalumab exhibiting superiority to placebo in ACR20 responses at week 12, and these responses continued to improve through 24 weeks and were sustained through the first 52 weeks of the trial.
Both firms have started two Phase III trials of brodalumab in psoriatic arthritis, AMVISION-1 and AMVISION-2, which will jointly provide detailed information on the impact of brodalumab on improving clinical signs and symptoms in psoriatic arthritis, as well as its ability to prevent joint damage.
Image: Magnetic resonance images of the fingers in psoriatic arthritis. Photo: courtesy of Stevenfruitsmaak.