Rare Daily Staff

The U.S. Food and Drug Administration approved Vertex Pharmaceuticals’ Symdeko for cystic fibrosis patients 12 and older who have two copies of the F508del mutation in the CFTR gene or at least one mutation that is responsive to medicine.

It is Vertex’s third medicine approved drug to treat the underlying cause of cystic fibrosis. The company expects approval in the European Union in the second half of 2018.

Cystic fibrosis is a rare, life-shortening genetic disease affecting approximately 75,000 people in North America, Europe and Australia. It is caused by a defective or missing cystic fibrosis transmembrane conductance regulator, or CFTR protein. There are approximately 2,000 known mutations in the CFTR gene. Some of these mutations, which can be determined by a genetic test, or genotyping test, lead to CF by creating non-working or too few CFTR proteins at the cell surface.

The defective function or absence of CFTR protein results in poor flow of salt and water into and out of the cell in a number of organs. In the lungs, this leads to the buildup of abnormally thick, sticky mucus that can cause chronic lung infections and progressive lung damage in many patients that eventually leads to death. The median age of death is in the mid-to-late 20s.

Some mutations result in CFTR protein that is not processed or folded normally within the cell, and that generally does not reach the cell surface. Symdeko is a combination of tezacaftor and ivacaftor. Tezacaftor is designed to address the trafficking and processing defect of the CFTR protein to enable it to reach the cell surface where ivacaftor can increase the amount of time the protein stays open.

February 13, 2018