Horizon Therapeutics ($HZNP@US) rose 32.9 percent in premarket trading after it announced a possible sale with several large pharmaceutical companies. Biogen ($BIIB@US) shares rose 3.6 percent after its partner Esai said it believed two deaths in their experimental Alzheimer’s drug could not be attributed to the treatment. Workday ($WDAY@US) shares rose 9.6 percent after the human resources software reported better-than-expected top and bottom line results for its latest quarter and announced a share buyback program.