Arena Pharmaceuticals, Inc. is focused principally on discovering and developing drugs that act on an important class of drug targets called G protein-coupled receptors (GPCRs). It focuses its drug discovery efforts across GPCR targets and compounds within four therapeutic areas: metabolic diseases, central nervous system disorders, cardiovascular diseases and inflammatory disorders. The Company uses CART, its constitutively activated receptor technology, as well as Melanophore technology and other technologies to better understand GPCRs and to identify compounds that may lead to new drugs. In 2003, Arena completed preclinical testing for its obesity drug candidate, APD356, in preparation for the Phase I clinical trials initiated in February 2004.