As expected, regulators in the USA have not approved Regeneron Pharmaceuticals' Arcalyst as a treatment for gout.

The US Food and Drug Administration has issued a complete response letter for the supplemental Biologics License Application for Arcalyst (rilonacept) for subcutaneous use for the prevention of gout flares in patients initiating uric acid-lowering therapy. The agency has requested additional clinical data, "as well as additional chemistry, manufacturing and controls information related to a proposed new dosage form".

The CRL comes as no surprise, given that an FDA panel voted unanimously (11-0) against recommending Arcalyst for this indication in May. The drug is already approved for the treatment of cryopyrin-associated periodic syndromes (CAPS), a set of rare genetic disorders.

Regeneron president George Yancopoulos said the firm is reviewing the CRL "and will determine appropriate next steps".