The United States Adopted Names (USAN) Council has approved the non-proprietary name lorcaserin hydrochloride for APD356, a selective 5-HT2C serotonin receptor agonist under investigation for the treatment of obesity. Lorcaserin hydrochloride, which is orally administered and was internally discovered by Arena pharmaceuticals, is expected to enter Phase 3 clinical development in the second half of 2006.

The USAN Council, tri-sponsored by the American Medical Association, the United States Pharmacopeial Convention and the American Pharmacists Association, serves the health professions in the United States by selecting simple, informative and unique non-proprietary names for drugs by establishing logical nomenclature classifications based on pharmacological and/or chemical relationships.

Lorcaserin hydrochloride, formerly designated by Arena as APD356, is a selective agonist of 5-HT2C serotonin receptors, which are located in the hypothalamus, an area of the brain that plays an important role in regulating food intake and metabolism.

Arena is developing a broad pipeline of compounds targeting an important class of drug targets called G protein-coupled receptors, or GPCRs, using its knowledge of GPCRs and its technologies, including CART (Constitutively Activated Receptor Technology) and Melanophore.