The underlying cause of cystic fibrosis (CF)

CF is caused by cystic fibrosis transmembrane conductance regulator (CFTR) protein defects. A mutation in the genes of a person with CF may make defective CFTR proteins that:

  • Don’t open correctly
  • Don’t get to the cell surface, where they are normally located

A person with CF may make CFTR proteins that have either or both of these defects.

Because of these defects, chloride ions cannot flow freely into or out of the cells as they should, leading to an imbalance of salt and water. This can lead to thick, sticky mucus in the lungs.


See how KALYDECO works

Watch a Video to See How KALYDECO Works

Learn how KALYDECO helps certain CFTR proteins work better. 

KALYDECO targets the underlying cause

CFTR protein diagram
CFTR protein diagram
CFTR protein diagram

KALYDECO affects gating of the CFTR protein. KALYDECO is used in people age 4 months and older who have at least one mutation in their CF gene that is responsive to KALYDECO.

In patients with a mutation in their CF gene that is responsive to KALYDECO, KALYDECO works to help the "gates" stay open longer, allowing more chloride ions to move into and out of the cells. The movement of chloride ions may help keep a balance of salt and water in the lungs. KALYDECO does not increase the number of CFTR proteins at the cell surface.

What is known about how KALYDECO works was learned from studies conducted in a lab. Keep in mind that results from laboratory studies do not always match how these medicines work in a person. If you have any questions about your KALYDECO treatment, please speak with your healthcare provider.