Arena Pharmaceuticals, Inc. announced today that data from its positive Phase 2a clinical trial studying APD356 in 352 obese patients was the subject of a presentation by Steven Smith, M.D., Principal Investigator and Associate Professor of the Pennington Biomedical Research Center, at the 2005 annual meeting of the North American Association for the Study of Obesity (NAASO). Over the 28-day treatment period in the trial, there was a highly statistically significant (p=0.0002) mean placebo adjusted weight loss of approximately 1 kilogram in patients taking the 15 mg dose of APD356. APD356 was generally well tolerated at all doses investigated in the trial. APD356 is a selective agonist of 5-HT2C serotonin receptors, which are located in the hypothalamus, an area of the brain known to play an important role in regulating food intake and metabolism.

Find more information about the APD356 diet drug from Arena Pharmaceuticals at http://biz.yahoo.com/prnews/051018/latu113.html?.v=25.