The New England Journal of Medicine ( NEJM ) has published data from the two phase 3 studies of Orkambi ( Lumacaftor / Ivacaftor ), an investigational medicine designed to treat the underlying cause of cystic fibrosis ( CF ) in people ages 12 and older with two copies of the F508del mutation, the most common form of the disease.

Data from the phase III TRAFFIC and TRANSPORT studies show that the combination has significantly improved lung function ( as measured by FEV1 ) by 2.6-4.0%, and has reduced the rate of pulmonary exacerbations by 30-39% in patients carrying two copies of the Phe508del CFTR mutation.

Cystic fibrosis is a rare genetic disease that is caused by defective or missing cystic fibrosis transmembrane conductance regulatory ( CFTR ) proteins resulting from mutations in the CFTR gene.
The defective or missing proteins result in poor flow of salt and water into and out of the cell in a number of organs, including the lungs.
In people with two copies of the F508del mutation, the CFTR protein is not processed and trafficked normally within the cell, resulting in little to no CFTR protein at the cell surface.

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. ( Xagena )

Source: The New England Journal of Medicine, 2015