New research shows a combination of two medications targets a genetic cause of cystic fibrosis, improving overall lung function.

Lumacaftor-ivacaftor therapy was shown to be safe and effective for the treatment of cystic fibrosis among patients with two copies of the cystic fibrosis gene mutation F508del, the Ann & Robert H. Lurie Children's Hospital of Chicago reported.

"These groundbreaking findings will benefit around 15,000 patients in U.S. alone," said Susanna McColley, one of the study's authors and Professor of Pediatrics at Northwestern University Feinberg School of Medicine. She also is the Director of the Clinical and Translational Research Program at the Stanley Manne Children's Research Institute, the research arm of Ann & Robert H. Lurie Children's Hospital of Chicago.

Cystic fibrosis causes thick mucus to fill the lungs, which can lead to chronic infections and reduced lung function. This mucus can also reach the pancreas and prevent food enzymes from being absorbed.  The recent phase III trial l included a total of 1,108 patients who were 12 years of age and older.

"While significant progress has been made with supportive therapies for cystic fibrosis, developing treatments that address the underlying genetic cause has been a challenge," said McColley who also is the Associate Director of the Cystic Fibrosis Center at Lurie Children's. "Just a few years ago, ivacaftor became the only FDA-approved drug for the genetic defect in cystic fibrosis, but it only works for genetic mutations found in a small portion of cystic fibrosis patients. Our study showed that combining ivacaftor with lumacaftor helps patients with the most common cystic fibrosis mutation. This is an exciting step forward."

The findings were published in a recent edition of the New England Journal of Medicine.