Arena Pharmaceuticals, Inc. (ARNA)

[Seminole Red]

A federal advisory panel Thursday narrowly rejected Vivus Inc.'s (VVUS, $5.17, -$6.94, -57.31%) experimental weight-loss drug Qnexa on concerns potential safety issues could be magnified if it were used by millions of patients. The news also weighed on fellow weight-loss drug maker Orexigen Therapeutics Inc. (OREX, $4.61, -$0.39, -7.80%), which will face the Food and Drug Administration later this year. But competitor Arena Pharmaceuticals (ARNA, $4.65, +$0.73, +18.62%) gained on the news, with JP Morgan upgrading its rating and saying there's a 65% probability of approval of its diet pill, Lorcaserin.