Cystic Fibrosis Drug a Game Changer?
Experimental Drug Ivacaftor May Extend Lives of Cystic Fibrosis Patients
Dramatic Improvement in Lung Function
The newly reported study included 161 cystic fibrosis patients as young as age 12 with a specific disease mutation known as G551D. About 4% of patients have the mutation.
All the patients in the study continued taking treatments to control their symptoms. Half also took the experimental oral drug twice a day for 48 weeks, while the other patients took placebo pills.
Over the course of the study, patients taking the experimental drug gained an average of 6 pounds more than the placebo-treated patients. And six months after beginning treatment their lung function had improved by 17%. Patients who took a placebo showed almost no improvement in lung function.
“When you consider that the typical cystic fibrosis patient loses about 2% of lung function a year, a 17% improvement in lung function is remarkable,” Beall says.
The ivacaftor-treated patients also saw dramatic reductions in their sweat’s chloride content -- an indication that the drug was working, as researchers had hoped, to modify the disease process by restoring the balance of salt and water within the body.
“When I first saw the results, I thought they couldn’t be real,” researcher Bonnie Ramsey, MD, of Seattle Children’s Hospital and the University of Washington School of Medicine tells WebMD. “You just don’t see changes like this.”
FDA Considering Ivacaftor Approval
Most patients in the study have remained on the drug, and researchers will present an additional 12 weeks of follow-up this week at the 25th Annual North American Cystic Fibrosis Conference in Anaheim, Calif., later this week.
They will also present data on children between the ages of 6 and 11 with the mutation who were treated with the experimental drug.
Cambridge, Mass.-based Vertex Pharmaceuticals, which is developing ivacaftor, is also developing a second experimental drug for use in patients with the most common cystic fibrosis gene mutation -- F508del.
About 90% of patients carry this mutation, and phase II trials are now under way to determine if the combination of the two experimental drugs can improve outcomes in these patients.
Vertex spokeswoman Dawn Kalmar says the FDA is reviewing the data on ivacaftor and the drug could be approved as early as the middle of next year.