FDA issues CRL for Kalydeco

Vertex Pharmaceuticals Inc. (NASDAQ:VRTX) fell $5.11 to $86.61 on Friday after FDA issued a complete response letter for an sNDA seeking to expand the label of cystic fibrosis drug Kalydeco ivacaftor to include patients two and older with one of 23 residual function mutations in the CF transmembrane conductance regulator ( CFTR) gene. Vertex markets the small molecule CFTR potentiator in the U.S. to treat CF in patients two and older who have one of 10 other mutations.

The sNDA was based in part on preclinical data for Kalydeco in the 23 mutations and data from an exploratory Phase IIa trial in 24 patients with eight of the 23 mutations. According to Vertex, there are more than 1,500 U.S. CF patients two and older with 1 of the 23 mutations. ...