The US FDA’s Pulmonary-Allergy Drugs Advisory Committee (PADAC) voted 12 to 1 to recommend approval of Orkambi (lumacaftor/ivacaftor) for use in people with cystic fibrosis (CF) ages 12 and older who have two copies of the F508del mutation in the CFTR gene, according to the drug’s manufacturer, Vertex Pharmaceuticals Inc.

The FDA is expected to make a decision on the approval of Orkambi by July 5, 2015 under the Prescription Drug User Fee Act (PDUFA), according to Vertex.

If approved, Orkambi will be the first and only medicine to treat the underlying cause of CF for eligible people with CF ages 12 and older with two copies of the F508del mutation in the CFTR gene. People with two copies of the F508del mutation represent the largest group of people with CF. There are approximately 8,500 people ages 12 and older with two copies of the F508del mutation in the US.

“Today’s positive recommendation brings the cystic fibrosis community one step closer to potential approval of the first medicine to treat the underlying cause of this disease for many more people,” said Jeffrey Chodakewitz, MD, executive vice president and chief medical officer at Vertex. “We look forward to continuing to work with the FDA and other regulatory agencies throughout the world to make Orkambi available to eligible patients as soon as possible.”

Orkambi is a combination of lumacaftor, which is designed to increase the amount of functional protein at the cell surface by addressing the processing and trafficking defect of the protein, and ivacaftor, which is designed to enhance the function of the CFTR protein once it reaches the cell surface. Orkambi is an oral medicine that, if approved, would be taken as fully co-formulated tablets that contain both lumacaftor and ivacaftor.