The US Food and Drug Administration (FDA) has granted approval for Vertex Pharmaceuticals' supplemental New Drug Application (sNDA) for Kalydeco (ivacaftor) for people with cystic fibrosis (CF) ages 6 and older who have one of eight additional mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene.

Kalydeco was first approved in January 2012 for people with CF ages 6 and older who have at least one copy of the G551D mutation. With the approval of the sNDA, Kalydeco is now approved for use in people with CF with the following nine mutations: G551D, G178R, S549N, S549R, G551S, G1244E, S1251N, S1255P and G1349D. In the United States, approximately 150 people ages 6 and older have one of the additional eight mutations for which Kalydeco is now approved.

CF is caused by defective or missing CFTR proteins that result from mutations in the CFTR gene. The defective function or absence of CFTR proteins in people with CF results in poor flow of salt and water into and out of the cell in a number of organs, including the lungs. Ivacaftor facilitates increased chloride transport by potentiating the channel-open probability (or gating) of the CFTR protein.

"We believe that Kalydeco has the potential to help more people with CF, and today's approval is an important step toward that goal," said Robert Kauffman, senior vice president and co-chief medical officer at Vertex. "As we progress over the coming year, we look forward to data from multiple other ongoing studies that are designed to evaluate whether additional people with CF may benefit from Kalydeco."

Kalydeco was granted Breakthrough Therapy designation by the US FDA in late 2012. The sNDA approval is based on previously announced data from a phase 3, two-part, randomized, double-blind, placebo-controlled, cross-over study of 39 people with CF who had one of the following mutations: G178R, S549N, S549R, G551S, G1244E, S1251N, S1255P, G1349D or G970R. The study showed statistically significant improvements in lung function (FEV1) for people in the overall study population who received ivacaftor, and the safety profile was similar to prior phase 3 studies in people with the G551D mutation. Based on data from four patients with the G970R mutation enrolled in the study, the efficacy of Kalydeco in patients with the G970R mutation could not be established to support approval in the US. Vertex estimates that approximately 10 people with CF have the G970R mutation worldwide, including two people in the United States.

Data from the study noted above were also used to support regulatory submissions in Europe, Canada and Australia for approval of Kalydeco in additional people with CF ages 6 and older. In Europe and Australia, approximately 250 people with CF have these additional mutations.

Kalydeco (ivacaftor) is the first medicine to treat the underlying cause of CF in people with specific mutations in the CFTR gene. Known as a CFTR potentiator, Kalydeco is an oral medicine that aims to help the CFTR protein function more normally once it reaches the cell surface, to help hydrate and clear mucus from the airways. Kalydeco (150mg, q12h) was first approved by the US Food and Drug Administration in January 2012 for use in people with CF ages 6 and older who have at least one copy of the G551D mutation and in February 2014 for use in people with CF ages 6 and older who have the following additional CFTR mutations: G178R, S549N, S549R, G551S, G1244E, S1251N, S1255P and G1349D.

Kalydeco was approved by the European Medicines Agency in July 2012, by Health Canada in November 2012 and by the Therapeutic Goods Administration in Australia in July 2013 for use in people with CF ages 6 and older who have at least one copy of the G551D mutation in the CFTR gene.

Vertex retains worldwide rights to develop and commercialize Kalydeco.

Vertex is a global biotechnology company that aims to discover, develop and commercialize innovative medicines so people with serious diseases can lead better lives.