Medications to Enhance CFTR Activity

Since the basic defect in cystic fibrosis (CF) involves a defective cell surface protein controlling chloride channel transport across cell membranes, medications which are developed to enhance the cystic fibrosis transmembrane conductance regulator (CFTR) protein should result in improvement in patients with CF. The presence of over 2000 genetic mutations have made these efforts difficult. However, a classifica‐ tion scheme of these mutations has allowed three basic approaches: to bypass missense mutations by having the cellular translation machinery read through the premature stop codon, to enhance the “gating” function of the CFTR protein on the cell surface, and to correct a defective CFTR protein “trafficking” though the cytoplasm to be inserted properly in the cell membrane. This chapter will review clinical trials using drugs which are designed to enhance CFTR protein activity.