European regulators have approved expanding the treatment scope of Vertex’ cystic fibrosis (CF) therapy Kalydeco (ivacaftor).

The decision allows for the drug’s use in infants with the condition aged six months to less than 12 months weighing 5kg and more who have at least one of the following nine mutations in their cystic fibrosis transmembrane conductance regulator.

According to the firm, the label update is based on data from the ongoing Phase III open-label safety study (ARRIVAL) of children with CF who are less than 24 months of age and have a CFTR gating mutation.

This showed a safety profile similar to that observed in previous Phase III studies of older children and adults, and improvements in sweat chloride, a secondary endpoint, Vertex noted.

“For the first time, children with CF in Europe as young as six months with certain mutations now have access to a medicine that treats the underlying cause of their disease,” said Reshma Kewalramani, executive vice president and chief medical officer at Vertex.

CF is a rare, life-shortening genetic disease affecting the lungs, liver, GI tract, sinuses, sweat glands, pancreas and reproductive tract. The condition is caused by a defective and/or missing CFTR protein resulting from certain mutations in the CFTR gene.

Kalydeco is an oral medicine designed to keep CFTR proteins at the cell surface open longer to improve the transport of salt and water across the cell membrane, which helps hydrate and clear mucus from the airways.