Cystic Fibrosis Study Points Way Forward for Gene Therapy

A therapy that repairs a mutated gene causing cystic fibrosis worked well enough in a U.K. trial to move ahead with follow-up testing, which could help bring forth a new treatment for the deadly lung disease.

While the therapy yielded a modest benefit in some patients, there was wide variability among the 136 people at least 12 years old who received monthly doses or a placebo for a year. After a year of treatment, in the 62 patients who received the gene therapy, lung function was an average of 3.7 percent greater than in the placebo group. The results were published Friday in the Lancet Respiratory Medicine journal.

“This is the first time a gene therapy has shown any benefit in cystic fibrosis patients,” Deborah Gill, associate professor of gene medicine at the University of Oxford, told journalists at a July 1 briefing in London. “We are hopeful we will get to an effective gene therapy” for the disease.

The study was conducted by a consortium of scientists at Imperial College London, Oxford, the University of Edinburgh and National Health Service clinics. While some patients felt better with the gene therapy, conditions didn’t improve for others, researchers said.

“There wasn’t a consistent response,” said Eric Alton, professor of gene therapy and respiratory medicine at Imperial College London and coordinator of the consortium. “It’s not yet ready for clinical use.” Follow-up studies will explore whether patients should take a higher dose or take it more frequently, he said.

Inhaled DNA

Cystic fibrosis is caused by a gene mutation located on chromosome 7 and results in thick mucus filling the lungs as well as recurrent chest infections. In the trial, patients inhaled molecules of DNA wrapped in fat globules known as liposomes that deliver a normal copy of the gene into the cells in the lung lining.

The results come one day after a new drug for the disease from Vertex Pharmaceuticals Inc. won U.S. approval.

If larger studies of the gene therapy show better efficacy, it may be possible to see the treatment reaching the market by the end of the decade, Alton said.

The scientists are also developing a second therapy that uses a safe virus to deliver the DNA into cells. That approach may be effective as a one-time treatment that could last several years. The consortium is in early discussions with pharmaceutical companies that have expressed interest in a collaboration, Alton said.