Niacin Receptor Agonists

In our partnership with Merck, we are collaborating on three GPCRs to develop therapeutics for atherosclerosis and other disorders. In October 2008, we announced that Merck completed a randomized, double-blind, placebo-controlled Phase 1 program of a second generation oral niacin receptor agonist under our partnership and, having evaluated safety, tolerability and pharmacokinetics, is planning to initiate a Phase 2 clinical program. We believe one or more of these GPCRs plays a role in regulating plasma lipid profiles, including HDL cholesterol, the so-called "good cholesterol," and is responsible for the HDL-raising activity of niacin. There are very successful drugs available for lowering LDL cholesterol. However, development of novel, effective therapies to increase HDL cholesterol remains a major focus of research. We believe that such therapies may reduce the risk of atherosclerotic heart disease and compete in the large dyslipidemia market.

The American Heart Association, or AHA, estimated that nearly 81 million American adults (one in three) have one or more types of cardiovascular disease which has caused more deaths in the United States than any other single cause or group of causes in every year since 1900, except 1918. The estimated direct and indirect cost of cardiovascular disease in the United States for 2008 is $448.5 billion. According to the AHA, the higher a person's HDL cholesterol level is the better. A level of less than 40 mg/dl in adults is considered low HDL cholesterol, which is a risk factor for heart disease and stroke. In 2005, HDL cholesterol levels in 17% of the United States adult population were below 40 mg/dl.

Our product candidates have not been approved by the U.S. Food and Drug Administration or any international regulatory agency.

(This page was last updated: November 19, 2008. Additional information regarding Arena is available in its SEC filings.)