US FDA rejects Regeneron's Arcalyst sBLA for gout flare prevention

US drugmaker Regeneron Pharmaceuticals (Nasdaq: REGN) says that the US Food and Drug Administration issued a Complete Response Letter for the supplemental biologics license application (sBLA) for Arcalyst (rilonacept) Injection for subcutaneous use for the prevention of gout flares in patients initiating uric acid-lowering therapy.

In the notification, which follows a negative advisory panel recommendation earlier this year (The Pharma Letter May 9), the FDA says it cannot approve the application in its current form. The agency has requested additional clinical data, as well as additional Chemistry, Manufacturing and Controls (CMC) information related to a proposed new dosage form. The FDA's action does not impact the drug’s current approved indication.

Arcalyst, which last year recorded sales of $20 million for Regeneron, is currently indicated in the USA 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. Rilonacept is also approved, but not marketed, in the European Union for the same patient population. The new indication would have added $128 million to turnover, according to the estimates of two analysts compiled by Bloomberg,