Shares of MannKind Corp. gained 15.6 percent Tuesday as the company prepares for its annual shareholder meeting amid takeover rumors. CNA Finance, a website that monitors social media for investment developments, posted a story Tuesday on its website that the web has plenty of talk – but no definite facts – about an acquisition of the Valenia biotech. “The CNA Finance team noticed that Amgen Inc. has been mentioned multiple times as a possible suitor,” the website stated. MannKind has announced news to fuel the takeover comments. On April 6 it disclosed in a Securities and Exchange Commission filing that the company signed a change of control agreement with its top seven executives. The agreement stipulates that should MannKind be acquired, the executives would continue to hold their positions for two years, would work at the same premises and would receive the same base salary. It also includes a severance package of 18 months’ salary plus health insurance if the executive is discharged after the two years. MannKind’s annual shareholder meeting is scheduled for May 18 at the company’s facility in Danbury, Conn. Shares of MannKind (MNKD) closed up 17 cents to $1.22 on the Nasdaq.