The first drug based on 'Trap' technology, which fuses two receptor components and a portion of an antibody molecule called the 'Fc' region, has been given marketing authorization by the US Food and Drug Administration (FDA). On February 27, 2008, the Tarrytown, New York-based Regeneron Pharmaceuticals received approval for Arcalyst (rilonacept), a treatment for cryopyrin-associated periodic syndromes (CAPS), including familial cold auto-inflammatory syndrome and Muckle-Wells syndrome. Arcalyst is a first-in-class drug designed using Regeneron's 'Trap' technology. The drug is a fusion protein comprising the human interleukin (IL)-1 type 1 receptor (extracellular domain and accessory protein) and the Fc portion of human IgG1. Regeneron's drug is the only therapy approved for CAPS, a group of rare, incurable, inflammatory diseases, generally caused by inherited genetic mutations that result in alterations in the cryopyrin protein, which regulates IL-1 production and results in IL-1 overproduction and inflammatory disease. Arcalyst is also in development to treat other IL-1-driven diseases, including gout. “There are long lists of diseases hypothesized to be driven by IL-1,” CEO Len Schleifer noted. “We are looking to test them relatively systematically over the years to come.” The Regeneron drug is competing with other IL-1 targeting drugs including Kinaret (anakinra), an IL-1 receptor antagonist approved to treat rheumatoid arthritis from Amgen of Thousand Oaks, California, and ACZ 885 (canakinumab), a fully humanized monoclonal antibody directed at IL-1β, from Novartis of Basel, Switzerland, currently in phase 3 trials for Muckle Wells syndrome. (Under a collaboration agreement with Novartis, Regeneron has the right to opt-in to jointly develop ACZ 885.)