People with cystic fibrosis, Australia’s most common inherited condition, have thick mucus, including on the lungs. from www.shutterstock.com May 3, 2017 Weekly Dose: Kalydeco, the drug that treats the cause of cystic fibrosis, not just symptoms Odette Erskine, University of Sydney Wider availability of the cystic fibrosis drug Kalydeco since May 1, 2017 means younger patients can now access it.