Cardiovascular safety concerns about Zafgen Inc.'s midstage type 2 diabetes (T2D) candidate, ZGN-1061, moved the FDA to push pause on the company's planned U.S.-based trial of the drug with a clinical hold. The setback triggered memories of a death tied to an earlier and now-discontinued candidate Zafgen had advanced from the same class, MetAP2 inhibitors, sending company shares (NASDAQ:ZFGN) down 40.6 percent to $5.41 on Monday.