BOSTON (Reuters) - An experimental drug made by Vertex Pharmaceuticals Inc significantly improved lung function in patients with cystic fibrosis, sending the company's shares up 18 percent to a four-year high.
Vertex said it will file for U.S. approval of the drug, known as VX-770, in the second half of this year.
Cystic fibrosis is an inherited disease that affects the lungs and digestive system. It affects about 30,000 people in the United States, according to the Cystic Fibrosis Foundation.
Results of a late-stage trial showed the drug improved lung function more than 10 percent, far greater than Wall Street had expected.
"These are potentially game-changing data in cystic fibrosis," Mark Schoenebaum, an analyst at ISI Group, said in a research note. "VX-770 is the first drug to show good data in a Phase III that actually modifies the disease by binding to a defective protein and fixing it."
In patients with cystic fibrosis, the thin layer of mucus that helps keep the lungs free of germs becomes thick, clogging the airways and leading to infections that damage the lungs.
Analysts estimate VX-770 could, if approved, generate peak annual sales of more than $500 million.
Vertex said it does not plan to seek a partner to help commercialize the drug.
The company expects to hear by the end of May whether U.S. regulators will approve its experimental hepatitis C drug, telaprevir, which it is developing with Tibotec Pharmaceuticals, a unit of Johnson & Johnson and Mitsubishi Tanabe Pharma.
Vertex's shares jumped 18 percent to $45 in premarket trading, a level not seen since the end of November 2006.
Reporting by Toni Clarke, Additional reporting by Lewis Krauskopf, editing by Maureen Bavdek