Zafgen, Inc.’s ZFGN shares plummeted 40.6% after the FDA put U.S. trials of the company’s experimental diabetes drug on hold, citing safety concernsShares of Cleveland-Cliffs Inc. CLF declined 1.3% after it announced a new $200 million stock buyback programAetna. Inc.’s AET shares gained 2.3% after CVS Health Corporation CVS received the final regulatory nod to acquire the companyShares of GW Pharmaceuticals plc GWPH increased 2.9% after the company announced positive top-line results for its cannabinoid-based childhood-onset epilepsy treatment, EpidiolexWant the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report GW Pharmaceuticals PLC (GWPH): Free Stock Analysis Report Zafgen, Inc. (ZFGN): Free Stock Analysis Report Aetna Inc. (AET): Free Stock Analysis Report Cleveland-Cliffs Inc. (CLF): Free Stock Analysis Report CVS Health Corporation (CVS): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research