*Prices reflect U.S. average retail price

Ivacaftor (trade name Kalydeco, developed as VX-770) is a drug used to treat cystic fibrosis in people with certain mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene (primarily the G551D mutation), who account for 4–5% cases of cystic fibrosis... Wikipedia

Manufacturer's Website: Kalydeco                                                                                                              Average retail cost: *

* This drug is only available at select specialty pharmacies, which usually means it may be expensive.