Clinical data reported by a handful of biopharmas on Dec. 19 sent stocks soaring or plunging, as company leaders laid out next-step plans. Investors showed enthusiasm for Omeros Corp.’s narsoplimab to treat hematopoietic stem cell-transplant-associated thrombotic microangiopathy (TA-TMA), and Roche AG’s Parkinson’s prospect prasinezumab, which is partnered with Prothena Corp. plc.