Hyperactive

LSP took advantage of the August doldrums and entered the hyperkalemia space with investments in ZS Pharma Inc. (NASDAQ:ZSPH) and Relypsa Inc. (NASDAQ:RLYP). Based on ZS Pharma's surge Thursday when it confirmed it was in talks with Actelion Ltd. (SIX:ATLN), the firm is looking at its best-ever IRR - on paper.

The investment rationale was clear: there are no good drugs for hyperkalemia and both companies have products under FDA review. ...