The FDA is slated to announce its decision on Vertex Pharmaceuticals Inc.’s (VRTX) New Drug Application seeking approval of Lumacaftor in combination with Ivacaftor in patients with cystic fibrosis who are two to five years of age on August 7, 2018.The combination of Lumacaftor and Ivacaftor is already approved by the FDA under brand name Orkambi for the treatment of the underlying cause of cystic fibrosis in patients 6 years and older with two copies of the F508del mutation in their CFTR gene.Orkambi is a blockbuster drug, and it generated annual revenue of $1.32 billion last year, up from $979.6 million in 2016.Cystic fibrosis is a serious genetic disorder caused due to F508del mutation. This disorder results in the formation of thick mucus that builds up in the lungs, digestive tract and other parts of the body leading to severe respiratory and digestive problems, as well as other complications such as infections and diabetes.It is estimated that about 30,000 children and adults in the United States have cystic fibrosis (Source: Cincinnati Children’s).VRTX closed Wednesday’s (Jul 25) trading at $176.81, up 1.10%.