Sanofi has reported late-breaking results from the Phase III open-label extension clinical trial of Dupixent (dupilumab) in children aged six to 11 years with moderate-to-severe asthma.

Named LIBERTY ASTHMA EXCURSION, the international, multicentre trial analysed the long-term safety and efficacy of Dupixent.

It enrolled 365 children with uncontrolled moderate-to-severe asthma who took part in the placebo-controlled, pivotal VOYAGE trial when they were aged six to 11 years. 

Trial subjects were given 100mg or 200mg Dupixent every two weeks, or 300mg Dupixent every four weeks for 52 weeks.

Evaluating the number of subjects experiencing any treatment-emergent adverse event (AEs) was the trial’s primary endpoint. 

The annualised rate of severe asthma exacerbations over a year and variation from trial baseline in FEV1pp were included as secondary endpoints.

According to the findings, the efficacy and safety profile of Dupixent as a maintenance treatment when given along with asthma therapies was consistent for up to two years in these subjects with uncontrolled moderate-to-severe asthma with evidence of type 2 inflammation.

In the extension trial, reduced severe asthma attack rates with an average of 0.118-0.124 events a year were reported, versus 2.16-2.56 events per year at baseline in the pivotal trial. 

Lasting improvement in lung function at 52 weeks of 9.43-12.6 percentage points from baseline was seen, as assessed by percent predicted FEV1 (FEV1pp). 

Children who switched from the placebo in the pivotal trial to Dupixent in the extension trial also had an 8.71 percentage point improvement in lung function at two weeks.

The safety data from the trial was in line with the previously reported safety profile of the therapy in approved respiratory indications.

The overall AEs were found to be 61%-68% for the treatment period of 52 weeks.

A fully human monoclonal antibody, Dupixent hinders the interleukin-4 (IL-4) and interleukin-13 (IL-13) pathway signalling.

Sanofi and Regeneron are co-developing the therapy under a worldwide partnership agreement.

In December last year, Sanofi reported that Dupixent boosted skin clearance in the Phase III trial for atopic dermatitis in children.