Phasebio Pharmaceuticals Inc., of Malvern, Pa., priced its IPO of 9.2 million shares at $5 apiece for gross proceeds of $46 million. Citigroup, Cowen and Stifel acted as joint book-running managers, while Needham & Co. LLC acted as co-manager. Shares began trading on Nasdaq Thursday under the ticker PHAS and closed flat.