CFTR and cystic fibrosis: For example, for the treatment of cystic fibrosis, Vertex first developed the CFTR enhancer ivacaftor based on in vitro screening, then a diphasic formulation of lumacaftor and ivacaftor that facilitates CFTR transport was developed under the trade name Orkambi for the treatment of F508del mutant CF, and finally the company developed a triple formulation of Trikafta targeting one or both F508del alleles (Zaher, 2021).