Q: I read that researchers are trying to treat cystic fibrosis with targeted therapies. What does that mean?

Cystic fibrosis is caused by a mutation or error in a particular gene. Children who inherit two copies of the faulty gene, one from each parent, can’t make a protein known as CFTR. There are more than 1,700 mutations or errors in that gene that can lead to CF. Researchers have been trying to find specific ways to target the more common mutations to repair the problem.

So far, they’ve been able to find targeted treatments for about 40 percent of people with CF. But Dr. Francis Collins, director of the National Institutes of Health who made some of the initial discoveries of mutated CF genes, recently blogged about a new discovery that could open up treatment to 90 percent of CF patients.

Preliminary results from three Phase 1 and 2 clinical trials testing a combination of drugs appear to improve lung function and sweat chloride tests for people with the most common mutation, known as F508del. Although the study was double-blinded and patients didn’t know what treatment they were getting, many of those on the new combination treatment noticed a difference in their health quickly, Collins said.

Vertex will use results of those trials, along with another study to begin later this year, to design a larger scale Phase 3 trial to test the combination’s effectiveness. It could, however, take several years to complete the trial and gain Food and Drug Administration approval for the treatment.

— Markian Hawryluk, The Bulletin