Regeneron Pharmaceuticals, Inc announced that treatment with Arcalyst (rilonacept), also known as IL-1 Trap, in a phase-2 study of gout patients initiating therapy with allopurinol to lower their uric acid levels, produced a statistically significant reduction versus placebo in the incidence of gout flares. In this 83-patient, double-blind, placebo-controlled study, the mean number of flares per patient over the first 12 weeks of urate-lowering therapy was 0.79 with placebo and 0.15 with Arcalyst (p=0.0011), an 81 per cent reduction. This was the primary endpoint of the study. All secondary endpoints also were met with statistical significance.

In the first 12 weeks of treatment, 45.2 per cent of patients treated with placebo experienced a gout flare and, of those, 47.4 per cent had more than one flare. Among patients treated with Arcalyst, only 14.6 per cent experienced a gout flare (p=0.0037 versus placebo) and none had more than one flare. No serious drug-related adverse events were reported in patients receiving Arcalyst treatment. Injection-site reaction was the most commonly reported adverse event with Arcalyst treatment. Detailed data from the study will be presented at a future scientific conference.

"These findings could be significant in the future management of patients with gout in that they address an impediment to successful long-term treatment. Allopurinol therapy is an important approach to lowering patients' high uric acid levels, which is the cause of their gout. However, the increased risk of painful gout flares over the first few months of initiation of uric acid-lowering therapy makes it difficult for patients to stick with treatment," said John Sundy, Division of Rheumatology, Department of Medicine, Duke University Medical Center. "Currently, colchicine or anti-inflammatory drugs are recommended for use to reduce the risk of gout flares in patients taking allopurinol, but these drugs may cause side effects and some patients do not tolerate them. The results from this study suggest that concomitant use of rilonacept during the first several months of allopurinol therapy may help avoid gout flares, which could, in turn, improve patient outcomes."

"We are encouraged about the potential role of Arcalyst (rilonacept) therapy in the treatment of gout. The results of this study, together with the findings of a previous small study of Arcalyst in patients with chronic, active gout, suggest that Arcalyst may provide utility in a number of different gout patient populations," stated George D Yancopoulos, president of Regeneron Research Laboratories. "Based upon these results, we plan to initiate a phase-3 clinical development programme early next year with Arcalyst in the prevention of gout flares in patients initiating urate-lowering drug therapy. Studies in other gout settings are also planned."

Gout is a condition that occurs when the bodily waste product, uric acid, is deposited in the joints and/or soft tissues. In the joints, these uric acid crystals cause inflammation, which leads to pain, swelling, redness, heat, and stiffness in the joints.

Arcalyst is indicated for the treatment of Cryopyrin-Associated Periodic Syndromes (CAPS), including Familial Cold Auto-inflammatory Syndrome (FCAS) and Muckle-Wells Syndrome (MWS) in adults and children 12 and older.

Regeneron is a fully integrated biopharmaceutical company that discovers, develops, and commercializes medicines for the treatment of serious medical conditions.