Mixed Outcome for Regeneron Candidate - Analyst Blog

Recently, Regeneron Pharmaceuticals Inc. (REGN) announced mixed results from two late-stage studies of its gout candidate Arcalyst (rilonacept). The company is evaluating Arcalyst for preventing or treating gout flares in patients, who have undergone therapies for lowering their uric acid levels.

One of the studies, known as PRE-SURGE 1 (PREventative Study against URate-lowering drug-induced Gout Exacerbations) met the primary goal of preventing gout attacks. However, another late-stage study, known as SURGE (Study Utilizing Rilonacept in Gout Exacerbations), demonstrated that Arcalyst failed to relieve pain significantly in patients already suffering an acute attack.

The PRE-SURGE 1 study (n=241) evaluated the number of gout flares per patient over the first 16 weeks following the initiation of allopurinol (the current standard of care) therapy. The double-blind, placebo-controlled study revealed that the 160 mg (weekly) dosage of Arcalyst reduced gout flares by 80% as opposed to placebo, while the 80 mg (weekly) dosage revealed a 73% reduction.

The SURGE study (n=225) evaluated pain during the initial 72 hours of treatment in patients suffering from an acute gout attack. The double-blind, placebo-controlled study failed to meet the primary goal of significantly reducing the average intensity of gout pain, as compared with a potent painkiller, indomethacin. Arcalyst was well tolerated in both the studies with no serious drug-related adverse events.

The company intends to file for a regulatory approval for Arcalyst as a preventive therapy by mid-2011, assuming positive results from two ongoing studies. The drug is already approved by the US Food and Drug Administration (FDA) for treating Cryopyrin-Associated Periodic Syndromes (CAPS) — a group of rare genetic inflammatory conditions, including Familial Cold Auto-inflammatory Syndrome and Muckle-Wells Syndrome. The drug is approved, but yet to be marketed for CAPS in Europe.

Gout, also known as metabolic arthritis, is a painful and debilitating disease caused by abnormally elevated levels of uric acid in the blood stream. This causes deposition of uric acid crystals in and around the connective tissue of the joints and in kidneys, leading to inflammation, formation of disfiguring nodules, intermittent attacks of severe pain and kidney damage. The incidence and severity of gout is increasing in the United States.

The market has a huge unmet need with Takeda’s Uloric (febuxostat), approved in February 2009, being the only new drug to be approved in the United States for the treatment of gout in the last 40 years. Apart from Regeneron, companies like Savient Pharmaceuticals, Inc. (SVNT), Ardea Biosciences Inc. (RDEA), Novartis (NVS) are also developing treatments for gout.

Currently, we have a Neutral recommendation on Regeneron.