Phase 2 clinical trial results were announced today for the cystic fibrosis transmembrane conductance regulator (CFTR) modulator candidate VX-659 in combination with tezacaftor and ivacaftor for people with CF who have two copies of the F508del mutation. VX-659 is one of two drug candidates that Vertex Pharmaceuticals Inc. recently decided would be moving into Phase 3 clinical trials.

The early stage study showed a significant improvement in lung function (9.7 percent increase in FEV₁ above baseline) and an improvement in sweat chloride (-42.2 mmol/L) when VX-659 was added to the treatment in participants with two F508del mutations who already were taking tezacaftor and ivacaftor.

In January, Vertex announced its decision to advance VX-659 and its other triple modulator candidate, VX-445, into Phase 3 clinical trials. Enrollment for the Phase 3 trials of VX-659 is expected to begin in the next several weeks. In mid-2018, Vertex also plans to begin a Phase 3 clinical trial for VX-445 in combination with tezacaftor and the compound VX-561 as a once-daily therapy in people with one F508del mutation and one minimal function mutation, and in people with two F508del mutations.

The Cystic Fibrosis Foundation provided $150 million in research funding to Vertex to support its pursuit of treatments that address the underlying defect in CF, including $75 million to develop next-generation candidates currently in clinical development.

For additional information regarding the results of these clinical trials, including the safety and efficacy outcomes, please see the Vertex press release.