Regulatory milestones

Arena Pharmaceuticals Inc. (NASDAQ:ARNA) jumped $2.54 (29%) to $11.39 on Wednesday after FDA approved an NDA for Belviq lorcaserin for chronic weight management. The approval triggered a $20 million milestone payment from marketing partner Eisai Co. Ltd. (Tokyo:4523; Osaka:4523). But the gains didn't last long; for the week, Arena was up $0.10 to $9.98 (see B10).