Morning Market Gainers

Weight Watchers International, Inc. WTW shares jumped 23.13 percent to $5.03 on takeover talks. Catabasis Pharmaceuticals Inc CATB shares surged 16.85 percent to $14.49 after the company reported that it has received the FDA Fast Track designation for CAT-1004 for the treatment of Duchenne Muscular Dystrophy. Versartis Inc VSAR shares rose 13.21 percent to $16.55 after the company announced the removal of the FDA partial clinical hold and continuation of VRS-317 Phase 3 clinical trial. Alliance Fiber Optic Products Inc AFOP climbed 9.64 percent to $20.35 after the company issued a strong Q2 revenue forecast. Celsion Corporation CLSN shares gained 5.11 percent to $2.47 after the company reported ongoing positive data from its Phase 2 DIGNITY study in breast cancer. Humana Inc HUM rose 1.89 percent to $191.04. Aetna Inc AET announced its plans to acquire Humana in a cash-and-stock deal valued at $35 billion.