 Shares of BioCryst Pharmaceuticals Inc. were down about 5 in premarket trading on Thursday after the company said it halted development of BCX9930, which was being tested as a treatment for paroxysmal nocturnal hemoglobinuria and some renal diseases, saying it no longer believes the therapeutic candidate is competitive commercially. BioCryst told investors that discontinuing the BCX9930 program will have a positive financial impact, and research and development expenses in 2023 will be similar to 2022s figures. 