HAMPTON BAYS - A newly approved drug is giving hope to the thousands of people living with cystic fibrosis. Dan Leichleider, 15, wears a vest every day to break up the thick, sticky mucus that is constantly building up in his lungs. The Hampton Bays teen has cystic fibrosis, a deadly disease that critically affects the lungs, pancreas, liver and intestines. Three years ago, Dan finally caught a break when he was asked to become part of a trial for a promising new drug called Kalydeco. He says it improved his lung function and quality of life. This January, the FDA approved the drug. It's the first ever to target the underlying cause of cystic fibrosis, a disease with a median life expectancy of just 37 years old. Unfortunately, out of the 30,000 people living with this disease nationwide, it only works on 4 percent of those suffering. While it's too early to tell what Kalydeco's long term affects are, many in the cystic fibrosis community say the new drug gives them hope.Breath of Hope: Southold girl battling cystic fibrosis