Healthy Living: November 5, 2019
Cystic Fibrosis (CF) is a severe genetic disease that affects more than 80,000 people worldwide. It is caused by a potentially deadly mutation in one pair of chromosomes responsible for the production of a protein necessary for normal respiratory and intestinal systems function. Those who inherit one of these abnormal chromosomes from one parent are called 'carriers' because usually the chromosome inherited from the other parent will be normal and capable of performing correctly. However, if one inherits this abnormal chromosome from both parents, then that individual will have no 'back-up' to code for the normal protein and will have a progressive disease characterized by intestinal blockages in infancy and severe respiratory compromise for the remainder of his or her life.
Historically, those with this dread diagnosis often did not survive to adulthood. In the past 30 years however, a lot of effort has gone into the development of aggressive treatment protocols for this chronic lung disease and now those with access to this care can live into early adulthood. In addition, genetic research now allows us the ability to identify carriers so that physicians can help parents prenatally avoid having children with the full-blown disease. Still as anyone who has experienced the challenge of having a family member with cystic fibrosis can tell you, medicine has been only 'nibbling at the edges' of the problem, and we have not had anything resembling a 'cure' for those unfortunate enough to inherit the condition.
That is until just recently. In last week's edition of the New England Journal of Medicine (DOI:10.1056/NEJMoa1908639) researchers announced a major breakthrough in the treatment of this disease. They reported on a placebo-controlled study involving more than 400 individuals with CF wherein half of the enrollees were treated with 'standard' care, and the other half with an experimental 'cocktail' of three unusual drugs (elexacaptor, tezacaptor, and ivacaptor) that have the ability to get into the lung cells involved in the production of the critical protein necessary for normal respiratory function. Even if these cells had both pairs of abnormal chromosomes, these medications could influence the cell machinery enough to produce some of the normal protein previously lacking.
When they looked at the lung function of those with the experimental drugs 24 weeks later, there was dramatic improvement in several areas. Overall there was a significant increase in FEV1, a marker for air movement. There also was a 63% lower rate of pulmonary exacerbations, and a quality of life scale that was 20 points higher in the treated individuals. Side effects were generally minor, with only 1% of those treated stopping the medications.
One major limitation of this study was the fact that the variant of CF showing the best potential for this treatment does not account for all those with CF. Because there are minor genetic differences in the chromosomes of people world-wide with this disease, the authors of this study focused on the most common type which accounts for 90% of those with CF, leaving 10% of those who have the diagnosis not seeing a benefit with this particular 'cocktail'. However, CF researchers expressed their commitment to continuing the search for similar medical technology to find effective treatment for all patients afflicted.
Still, this study marks a milestone in our ability to make a real difference for those suffering from this cystic fibrosis. If these disease-altering treatments prove effective, it may allow us to rethink what it means to have CF. Rather than looking at CF as a 'lethal disease' it may be more useful to consider it a chronic life-long condition, akin to diabetes. As one researcher expressed it, those with CF very commonly did not even consider going to college as young adults because they did not want to waste the time/resources if they were unlikely to have a meaningful work- life. Now, not only do those with cystic fibrosis need to think about higher education, they also might want to consider putting something away for their retirement, a lifespan goal that was previously unimaginable for this population.