Antidote: On Cystic Fibrosis treatments
Marc Siegel, MD
Cystic Fibrosis is the second most common life-threatening inherited disorder in the US. About 30,000 Americans have it, and there are around 1,000 new cases diagnosed each year.
Recent treatments in CF, including the inhaled antibiotic Tobramycin, have increased lifespan well into adulthood. Many end up needing lung transplant, but there are a limited number of lungs available. 900 lung transplants are performed in the U.S. every year but only 150 are for CF.
But since CF is a genetic disease, the future of treatment lies not with antibiotics or with transplantation but with genetic treatments. And this month, in news that was largely overlooked in the media, Vertex Pharmaceuticals announced a combination of two genetic treatments which together improved the lung capacity of CF patients who were less likely to get sick, require antibiotics, or need to be hospitalized.
It was in 1988 that scientists first showed that CF was caused by a mutation. The new studies combine the drug Kalydeco—which works on a small percentage of CF patients with a G551D mutation—and lumacaftor. When the two were combined they improved lung function slightly in those patients with the far more common F508del mutation. Perhaps more importantly, they enabled these patients to gain weight, and offered them some protection against pulmonary infections which could land them in the hospital.
The combination of the two drugs works on a metabolic level by correcting a dysfunction in a CF regulator protein and improving chloride transport.
In the future, genetic and protein altering treatments for CF will become more effective and more personalized. In the meantime, the success of the Vertex treatment is an indication that scientists are finally moving in the right direction. Once upon a time CF was a certain death sentence. Now the average lifespan of a CF patient who lives to adulthood is age 37.
Expect that number to climb dramatically—and soon.