Shares of Alkermes plc slipped 15% Nov. 9 on news that longtime partner Janssen Pharmaceutica NV plans to partially terminate two license agreements related to know-how royalties on U.S. sales of paliperidone products using Alkermes’ nanoparticulate technology. While the move is expected to result in only a modest near-term impact on the Dublin-based firm’s bottom line, it took both company management and investors by surprise.