Arena Pharma climbs on positive data from early study of autoimmune disease drug ADP334

Markets Associated Press

Shares of Arena Pharmaceuticals surged Wednesday after the drugmaker reported positive results from an early clinical trial of a possible treatment for autoimmune diseases.

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The San Diego company said its drug ADP334 reduced patients' lymphocyte counts in an early-stage study of 50 healthy volunteers compared with a control group that received a placebo. Arena Pharmaceuticals said that measurement is linked to success in clinical studies of other treatments for multiple sclerosis, psoriasis, and ulcerative colitis.

Shares of Arena Pharmaceuticals Inc. gained $1.52, or 45.8 percent, to $4.84 in midday trading.

Arena Pharmaceuticals gets most of its revenue from the weight loss drug Belviq, which was approved in 2012. Sales have been far below expectations due to limited insurance coverage and high out-of-pocket costs for patients, and Arena reported $5.7 million in net sales of the drug during the third quarter.