The stock has fallen from a peak back in April.Vertex Pharmaceuticals (VRTX 0.45%) has grown revenue and profit into the billions of dollars thanks to its expertise in the treatment of cystic fibrosis (CF). The company has developed a portfolio of drugs that has transformed the way the disease is treated -- and that's made Vertex the No. 1 player in the industry.In recent years, the biotech has expanded into other treatment areas, even scoring regulatory approval for a gene editing therapy for blood disorde ...