In 2012, the Food and Drug Administration approved the oral drug, Ivacaftor for treatment in patients over 6 years of age with a specific mutation of CFTR: G511D. This was the first drug to target the gene defect and not the symptoms of CF. G551D is a class III mutation and accounts for about 4% of CF cases. In this mutation, CFTR is synthesized and moves to the cell membrane but the chloride channel does not function. In clinical trials, patients on ivacaftor had improvement in lung function, decreased sweat chloride concentrations, and increased weight gain compared to placebo.
An oral drug combination with ivacaftor and a second drug, lumacaftor has shown promise in clinical trials at treating patients who are at least 12 years old and have 2 copies of the most common CFTR mutation, F508 del. Patients showed improved pulmonary function and weight gain and fewer hospitalizations compared to placebo. Lumacaftor helps the defective CFTR reach the cell surface while ivacaftor increases the activity of the chloride channel. Studies are ongoing to test the safety and efficacy of these newer drugs in younger patients as well as novel drugs to treat other mutations of CFTR.