Expanding approved indications is a sure-fire way to boost a drug’s sales. Vertex Pharmaceuticals Inc.’s (VRTX) expects to hear the FDA decision on label expansion of Orkambi in children with cystic fibrosis ages 6 to 11 who have two copies of F508del mutation on September 30, 2016.Having two copies of F508del mutation (one inherited from each parent) is the leading cause of cystic fibrosis.Orkambi was approved by the FDA last July to treat cystic fibrosis in patients 12 years and older, who have the F508del mutation.Since its launch in July 2015 through the second quarter of 2016, Orkambi has fetched the company $819 million in revenue.Will the FDA greenlight Orkambi for use in children with cystic fibrosis younger than age 12 years?