SALT LAKE CITY -- In October 2011, an expedited request for approval of the revolutionary new drug Ivacaftor to treat cystic fibrosis was submitted to the FDA.
The drug, which will be marketed under the brand name of KALYDECO, and the results of the trials recently appeared in the New England Journal of Medicine.
“I cannot really speculate about the FDA process," said Utah CF expert Dr. Theodore Liou, M.D. "(The results are) extremely positive and quite convincing that the drug will have a major impact on the lives of our patients.
"I doubt that it will be less than a year, but I am hoping that it will be available before two years pass.”
Liou has quietly been conducting trials for the new drug at the Intermountain CF Center, Primary Children's Medical Center and University of Utah. His clinic is part of the CF Foundation's Therapeutic Development Network and is the only certified TDN clinic in Utah.
“We participated in three of the four clinical trials and are continuing participation in a follow on trial. Our first involvement was since Spring of 2008," he said. "At our site, we enrolled nine patients in the first trial and six in the second. Our patients are from all over the state with some from Idaho and Nevada. The patients that entered the study were all from our own center, some were from outside of Salt Lake City itself, but most were from within the Salt Lake valley.”
Thanks to Liou and his medical colleagues, the University of Utah has a cutting-edge program that teaches students in their medical school about CF. He personally teaches interns, residents and pulmonary fellows about CF. He emphasizes how to diagnosis CF and how to perform basic treatments. Additionally, he has given teaching conferences at a number of local hospitals to try to spread knowledge about CF, its diagnosis and care.
Cystic fibrosis patients with the G 551D mutation will initially receive the most benefit from the new drug, even though they are a mere 4 percent of the CF population.
Another drug referred to as VX-809 is also under development that would be used in combination with Ivacaftor that will likely benefit over 90 percent of those with the disease when used in combination with Ivacaftor, but that drug is not ready for market and is still in trials.
It is estimated that in the U.S. there are 30,000 persons and worldwide 70,000 that suffer from the disease.
CF is caused by a defective protein known as CFTR, which is responsible for regulating the flow of chloride across the cell surface in the lungs to help hydrate and clear mucus from the airways. In people with the most common mutation in the CF gene known as the F508del, the CFTR protein does not reach the cell surface in normal amounts, resulting in a buildup of mucus and other complications that can lead to lung damage. This type of CF is one of the most severe forms of the disease and leads to chronic lung infections and progressive and permanent irreversible lung and organ damage.
The major surprise during the trials was that patients on the drug uniformly had an improvement in weight. CF patients are usually undernourished because the disease leads to malabsorption of protein and calories. The drug was not expected to correct this, and there is no plausible explanation for this positive side effect.
The incident of CF is highest in persons of Northern European decent.
Utah residents experience one of the highest rates of CF in the United States. Treatment has been limited to inhaled antibiotics two times a day for 20 minutes, or inhaled hypertonic saline that takes over an hour a day, and just doing the airway clearance can easily take well over an hour to administer.
These estimates do not take into account prep, setup and cleanup for the procedures. It is time consuming and invasive with high risks for infections. The new proposed drug would dramatically improve treatment options. It would allow the person to take an oral medication in much the same way many take vitamins or other pill form medications.
In CF, thick, sticky mucus blocks the passages in many organs, leading to a variety of symptoms. In particular, mucus builds up and clogs airways in the lungs making it easier for bacteria to grow. Repeated infections and chronic inflammation cause lung and other irreversible organ damage which is a leading cause of death in people with CF.
Most people with CF have very short life spans, usually 11-38 years, depending on the severity of the disease, and sympto ms seem to get worst with age until the body eventually shuts down.
This is the first therapy for CF that directly addresses the primary defect — the non-working chloride channel protein that the CF gene encodes. All previous therapies have addressed some downstream effect of the gene mutation.
“It is likely to have as big an impact on patients with the G551D mutation as the discovery of penicillin for pneumococcal pneumonia,” says Liou.
Patients with the G551D mutation will likely have a reduction in severity of disease, a major slowing of progression of existing lung damage (bronchiectasis) and a decrease in the intensity of needed treatments.
“I think that there will be a major improvement in life," Liou said. "For young patients, with early detection, the drug may eliminate the need for additional therapies."
The best hope for early detection is genetic testing.
The broad perspective shows that treatment tailored to a specific genetic mutation is possible. At this point, it has required enormous effort and many resources, both scientific and financial. Success may indicative of further successes for CF and for other diseases where genetic mutations are a major cause of disease.
The most significant drawbacks to the research or treatment require knowledge of the mutation, the mechanism of the mutation to cause disease, and a massive effort to find molecules that correct the mutation.
The specificity of the treatment limits the target population for the treatment to a very specific group that all have the mutation. Most other patients with CF have similar disease characteristics, but will not benefit directly from the drug.
The financial drawback of such targeted therapy is that there are few patients with CF and the G551D mutation so that the cost of the drug is likely to be very high, although at present there is no estimate of cost available yet.
“It is not yet clear exactly how this drug will fit into the range of treatments for CF," Liou said. "For patients starting the drug very young, before permanent and major lung damage in the form of bronchiectasis has occurred.
It is possible that no other therapy will be needed. For those that have established bronchiectasis, there will likely be a continuing need for airway clearance and antibiotic therapy in various forms. However, we are very hopeful that the intensity of treatment will be able to be reduced, perhaps dramatically, by the new drug.”
For additional information, visit www.cff.org.
Mel Borup Chandler lives in Southern California and frequently reports on similar stories. His email address is firstname.lastname@example.org.