Shares of Vertex Pharmaceuticals Inc. soared nearly 50 percent in pre-market trading Monday after the drug developer said it saw better-than-expected results in a mid-stage study of a potential treatment for the most severe form of cystic fibrosis.
The Cambridge, Mass., company said an early analysis of a combination of its pill Kalydeco and a molecule labeled VX-809 that has yet to receive approval showed an improvement in lung function in patients with the most common gene mutation in the disease.
About 30,000 Americans live with cystic fibrosis, a disease that causes sticky mucus to build up in the lungs and other organs, leading to infections, digestive problems and death in young adults.
A Vertex spokeswoman said about half of cystic fibrosis patients have the gene mutations seen in the early results announced Monday.
Vertex said complete data from the study will be available by mid-year.
Kalydeco received Food and Drug Administration approval Jan. 31 for a treatment for a rare form of the disease that affects just 1,200 people in the U.S., or 4 percent of the population with cystic fibrosis. It received approval as the first drug to treat the root cause of the disease.
Vertex shares jumped 48.8 percent, or $18.24, to $55.65 before markets opened Monday.

