The US Food and Drug Administration (FDA) has accepted a new drug application (NDA) for United States-based Vertex Pharmaceuticals' VX-445 (elexacaftor), tezacaftor and ivacaftor triple combination regimen, it was reported yesterday.

The FDA has sanctioned Priority Review of the new drug application and assigned a Prescription Drug User Fee Act (PUDFA) target action date of 19 March 2020. The submission was supported by earlier revealed positive results of two global Phase three studies in patients with cystic fibrosis (CF): a 24-week Phase three study in people with one F508del mutation and one minimal function mutation, and a four-week Phase three study in people with two F508del mutations.

Both Phase 3 studies indicated statistically significant improvements in lung function (percent predicted forced expiratory volume in one second; ppFEV1), which was the primary endpoint, and in all key secondary endpoints. In these studies, the triple combination regimen was generally well tolerated.