So far, there is no cure for cystic fibrosis but researchers are working hard to find one. Many people believe that someday soon, there will be. We definitely are a lot closer now than ever before. The vast body of research that has been done over the last couple of decades has taught us a lot about cystic fibrosis, given us many new drugs and treatments that have dramatically improved both life expectancy and quality of life, and opened doors to new research that could lead to a cure.
Some of the possible cures being studied:
In 1989, the gene responsible for causing cystic fibrosis was discovered. This was an exciting discovery for the CF community. Many believed the discovery would lead to a cure through gene therapy. Unfortunately, that has not happened yet – but not for the lack of trying. Numerous studies have been done to try and correct the genetic defect but none of them have been successful. The biggest problem with gene therapy so far has been finding a vector that can effectively carry the corrected gene to the cells. There may still be hope for gene therapy, though. In July 2009, a group of researchers at the University of North Carolina – Chapel Hill had very good results using a common cold virus as a vector to transfer the gene in laboratory samples of lung tissue. The research team is now working on a way to weaken the cold virus so the treatment can be tested in people with cystic fibrosis.
VX-770 is a drug being tested by Vertex Pharmaceuticals in people with cystic fibrosis who have at least one copy of the G551D mutation. The drug may actually be able to target the defect in the CFTR gene and restore its ability to open up chloride channels, thus allowing salt to flow in and out of the cells properly. Unlike gene therapy, VX-770 would not replace the defective gene. Rather, if successful, VX-770 would repair the problem in the existing gene.
VX-809 is another drug being tested by Vertex Pharmaceuticals in people who have two copies of the ∆F508-CFTR mutation. It is similar to VX-770 in that it may be able to get salt flowing through the cells properly, but it works a little differently. If it works as researchers hope it will, VX-809 would open chloride channels by moving the CFTR protein to its proper place on the airway cell membrane.
Miglustat is a drug manufactured by Actelion Pharmaceuticals that is already in use to treat other conditions, but it is currently being studied for use in people with cystic fibrosis who have two copies of the ∆F508-CFTR mutation. The study is small scale -- consisting of only 15 participants -- but so far the results have been promising as Migulstat has been able to reverse the CFTR defect and restore normal activity to cells.
Ataluren, which was once called PTC124, is being studied by PTC Therapeutics as a possible cure for people with CF who have nonsense mutations. In nonsense mutations, a piece of “gibberish” code appears amidst the normal code in the CFTR gene. The nonsense code acts like a stop sign, preventing the cells from reading any code that occurs after it. Ataluren may be able to correct that problem by helping the cells to ignore the stop sign and keep reading the code that occurs after it, thus restoring normal function to the cells.
C. Norez, F. Antigny, S. Noel, C. Vandebrouck, F. Becq. “A CF Respiratory Epithelial Cell Chronically Treated by Miglustat Acquires a Non-CF Like Phenotype”. American Journal of Respiratory Cell and Molecular Biology. August 2009.
Cystic Fibrosis Foundation. June, 2009Drug Development Pipeline. 24 July 2009.
Zhang L, Button B, Gabriel SE, Burkett S, Yan Y, et al. 2009 “CFTR Delivery to 25% of Surface Epithelial Cells Restores Normal Rates of Mucus Transport to Human Cystic Fibrosis Airway Epithelium”. PLoS Biol 7(7): e1000155. doi:10.1371/journal.pbio.1000155. 24 July 2009.