The FDA is scheduled to announce its decision on Vertex Pharmaceuticals Inc.’s (VRTX) New Drug Application for Tezacaftor/Ivacaftor combination treatment on February 28, 2018.The Company is seeking approval of the combo therapy for use in people with cystic fibrosis ages 12 and above with either one or two copies of the F508del mutation.Cystic Fibrosis is a rare, life-shortening genetic disease where a defective gene causes the buildup of abnormally thick, sticky mucus that can cause chronic lung infections and progressive lung damage in many patients that eventually leads to death.If approved, the Tezacaftor/Ivacaftor combo treatment would become Vertex's third medicine to treat the underlying cause of cystic fibrosis - the other two being Kalydeco and Orkambi.VRTX closed Thursday’s (Jan.25) trading at $166.24, down 0.72%.