Vertex reports Phase II trial results of VX-661 in combination with ivacaftor for cystic fibrosis

According to the company, the combination was generally well tolerated and all patients completed 12 weeks of treatment.

The trial evaluated two doses of VX-661 100mg once daily or 50mg every 12 hours in combination with ivacaftor 150mg every 12 hours.

Vertex executive vice-president and chief medical officer Dr Jeffrey Chodakewitz said: "The safety and efficacy data from this study are consistent with prior Phase II studies of VX-661 in combination with ivacaftor and provide further support for our ongoing Phase III program in people with one or two copies of the F508del mutation."

The trial’s primary endpoint was safety and secondary endpoints evaluated the effect of the combination on lung function, and the mean within-group absolute improvement from baseline in ppFEV1 for those who received 100mg of VX-661 in combination with ivacaftor was 4.4% and 3% points at week four and through 12 weeks of treatment, respectively.

The safety and efficacy data, together with other data from multiple previously completed Phase II trial of VX-661, support the company’s ongoing Phase III program of VX-661 in combination with ivacaftor.

The Phase III program is evaluating VX-661 100mg once daily in combination with ivacaftor 150mg every 12 hours and it includes four Phase III trials, including a study in people with two copies of the F508del mutation that started enrollment in February.

The other three trials will begin enrolling people with CF who have one copy of the F508del mutation and a second mutation that is either a gating mutation, residual function mutation or a mutation that results in minimal CFTR function.

The most common adverse events observed in the Phase II trial were pulmonary exacerbation, which occurred in 38% of all patients who received VX-661 and 44% of those who received placebo, and cough, which occurred in 33% of all patients who received VX-661 and 39% of those who received placebo.