On Monday, Cambridge-based Idera Pharmaceuticals announced plans to merge with BioCryst Pharmaceuticals, based in Durham, North Carolina, with the resulting company to be based in Exton, Pennsylvania. The combined company – to be renamed upon the merger’s closing – will be headquartered in Exton, with a consolidated research center slated for Birmingham, Alabama. As part of the all-stock deal, a spokesman for Idera (Nasdaq: IDRA) said Monday that eventually that company's current Cambridge…