Vertex Seeks FDA Approval for Triple Combination Cystic Fibrosis Regimen

Vertex Pharmaceuticals said it has submitted an application to the U.S. Food and Drug Administration for its triple combination of VX-445 (elexacaftor), tezacaftor, and ivacaftor to treat cystic fibrosis.

Cystic Fibrosis (CF) is a rare, life-shortening genetic disease. It is caused by a defective or missing cystic fibrosis transmembrane conductance regulator (CFTR) protein resulting from mutations in the CFTR gene. Children must inherit two defective CFTR genes—one from each parent—to have CF. There are approximately 2,000 known mutations in the CFTR gene. Some of these mutations, which can be determined by a genetic 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 early 30s.

Vertex’ application includes a request for Priority Review, which, if granted, would shorten the FDA’s review of the NDA to eight months from the time of submission, versus a standard review timeline of 12 months from submission.

The submission is supported by previously disclosed positive results of two global phase 3 studies: a 24-week phase 3 study in people with one F508del mutation and one minimal function mutation and a 4-week phase 3 study in people with two F508del mutations. Both phase 3 studies showed statistically significant improvements in lung function, which was the primary endpoint, and in all key secondary endpoints. In these studies, the triple combination regimen was generally well tolerated.

“The submission of the NDA is a major step toward our goal of bringing this medicine to the largest remaining group of people with CF that still do not have an approved Vertex medicine, as well as toward providing significantly enhanced benefits to patients with two F508del mutations,” said Reshma Kewalramani, executive vice president and chief medical officer at Vertex. “We will continue working with the FDA as they review the NDA and look forward to the potential of this triple combination regimen becoming a new treatment option for people with CF.”

The triple combination regimen was granted Breakthrough Therapy designation in May 2018. Breakthrough Therapy designation is a process designed to expedite the development and review of drugs that are intended to treat a serious condition and for which preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over available therapy on a clinically significant endpoint.

Author: Rare Daily Staff