Vertex To Initiate Phase 3 Program For Once-Daily Triple Combination Regimen In Cystic Fibrosis

(RTTNews) - Vertex Pharmaceuticals Inc. (VRTX) said that it will initiate a phase 3 development program for the new once-daily investigational triple combination of VX-121/tezacaftor/VX-561 (deutivacaftor) in people with Cystic Fibrosis. The Phase 3 program is expected to begin in the second half of 2021.

The Phase 3 program consists of two randomized, double-blind, active-controlled 48-week trials, which will evaluate the safety and efficacy of VX-121 (20 mg)/tezacaftor (100 mg)/VX-561 (250 mg) in comparison to TRIKAFTA. The first study will enroll about 350 people with CF ages 12 years and older with one F508del mutation and one minimal function mutation (F/MF). The second study will enroll approximately 450 people with CF ages 12 years and older with two F508del mutations (F/F) or one F508del mutation and a second mutation responsive to CFTR modulators.

Phase 2 data suggested the triple combination holds the potential to restore cystic fibrosis transmembrane conductance regulator (CFTR) function in people with cystic fibrosis to even higher levels than seen with other Vertex CFTR modulators and thereby provide enhanced clinical benefit.

The combination of VX-121/tezacaftor/VX-561 was first identified as having potential for increased efficacy based on its ability to drive higher levels of chloride transport compared to TRIKAFTA in human bronchial epithelial cells in vitro.

The combination of VX-121/tezacaftor/VX-561 was evaluated in a Phase 2 study in people with cystic fibrosis (CF) ages 18 and older with one F508del mutation and one minimal function mutation (F/MF) and in people with CF ages 18 and older with two F508del mutations (F/F).

The regimen was generally well-tolerated, and the study met the primary efficacy endpoint of absolute change from baseline in ppFEV1 and all secondary efficacy endpoints including absolute change from baseline in sweat chloride concentration in both patient populations.