Gilead Sci­ences is buy­ing its CAR-T col­lab­o­ra­tor Ar­cel­lx as its close­ly watched mul­ti­ple myelo­ma cell ther­a­py nears po­ten­tial ap­proval and launch. The deal is worth $7.8 bil­lion, when cal­cu­lat­ed from $115 per share in cash...