The US Food and Drug Administration (FDA) has issued a Complete Response Letter to Vertex Pharmaceuticals Incorporated for its supplemental new drug application (sNDA) for the use of Kalydeco (ivacaftor) in people with cystic fibrosis (CF) ages two and older who have one of 23 residual function mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The FDA determined that it cannot approve the application in its present form. Vertex plans to meet with the FDA to determine an appropriate path forward.

Vertex is seeking an additional indication for the drug. There are more than 1,500 people ages two and older with CF in the United States who have one of the 23 residual function mutations included in the sNDA.

Kalydeco is approved for the treatment of cystic fibrosis (CF) in patients age two years and older who have one of the following mutations in their CF gene: G551D, G1244E, G1349D, G178R, G551S, S1251N, S1255P, S549N, S549R, or R117H.

Source: Vertex Pharmaceuticals