Maren Denison, third-year student at the University of Iowa, was in sixth grade when she found out her lung function had dropped to 60 percent as half of her lung had collapsed and was scarred shut. As the weeks progressed, Dension’s lung function continued not to improve, and doctors told her she would have to live the rest of her life with just over half lung function.
When provided the option to participate in a new drug trial for cystic fibrosis at UI Health Care, Denison jumped at the opportunity. Within a few months of taking the drug, Denison saw her quality of life improve.
Cystic fibrosis is a genetic disease inherited in an autosomal recessive pattern, meaning both parents of an individual have an abnormal copy of the gene causing cystic fibrosis, Dr. David Stoltz, said.
Dr. Michael Welsh, a UI professor of internal medicine-pulmonary and critical care and occupational medicine, has led discoveries and collaboration in cystic fibrosis research, winning the 2025 Lasker-DeBakey Clinical Medical Research Award, according to UI Health Care.
The award was granted to Welsh by the Lasker Foundation for his advancement of cystic fibrosis research and the development of new therapies to combat the genetic disease. With multiple mutations of cystic fibrosis, Welsh and his team were able to identfy how to correct defects within the cystic fibrosis gene.
In the early 1990s, Welsh and his team at Iowa discovered that the CFTR protein functions as a chloride ion channel and showed how CF-causing mutations disrupt the protein’s folding and function.
Building on this research, the team at Vertex Pharmaceuticals developed a new class of drugs, which included Trikafta, helping to restore CFTR protein function, Jennifer Brown, communications specialist at UI Health Care, said.
“The striking improvements for people with cystic fibrosis have been greater than I could have hoped for. When I was a medical student, I saw the suffering and death of children with CF. Now, I see children and adults with cystic fibrosis who live their lives without the struggles that plagued patients just a few years ago,” Welsh said in a statement to The Daily Iowan.
Denison developed cystic fibrosis-related diabetes following her diagnosis at birth, alongside her twin brother.
“This [cystic fibrosis-related diabetes] was interesting to get because it is probably the hardest part of having cystic fibrosis, having to manage my diabetes for every second of the day,” Denison said.
Prior to the birth of her and her twin, Denison’s parents were told their babies had cystic fibrosis and then told they did not.
“It was a real awakening for my parents on how to handle that situation when me and my brother were born with CF,” Denison said. After spending 63 days in the neonatal intensive care unit, Denison remained out of the hospital until she was roughly 3 years old. She spent weeks in the hospital throughout her life due to her condition.
In 2017, Denison wound up in the hospital once again, this time for three weeks.
“This was really hard because I was already in school at this point, so it was completely different than what was happening to everyone else in sixth grade,” Dension said.
Stoltz, a professor of medicine at the UI and chief of the division of pulmonary critical care and occupational medicine, said Trikafta is a modulator, a type of medication working to treat cystic fibrosis, containing three separate drugs. The drug targets the mutation in the CFTR gene known as delta f508.
Denison, a carrier of the delta f508 mutation, saw her lung function return to 100 percent and has been able to stay out of the hospital since.
“I could finally take a deep breath of air, and I kept telling my mom, ‘Mom, I can breathe for forever. This is amazing,’” Denison said.
Kelsey Logan, virtual connection senior specialist with the Cystic Fibrosis Foundation and carrier of the Cystic Fibrosis Transmembrane Conductance, or CFTR gene, was told she wouldn’t live past the age of 30. Now 37, Logan is the mother of two young boys and actively living with cystic fibrosis.
Many people like Logan have surpassed this life expectancy. According to the National Institute of Health, for those individuals born in the 1990s, the average life expectancy was approximately 40 years, a number that had doubled from the 1970s. Now, that life expectancy number can be up to 80 years old.
The number of adults and children living with cystic fibrosis in the U.S. is roughly 40,000, according to the American Lung Association. Roughly 1 in 30 people are a carrier of the CFTR gene.
Stoltz said on average, roughly 25 percent of kids whose parents are carriers of the CFTR gene go on to develop cystic fibrosis. Mutations within the CFTR gene are ultimately responsible for causing cystic fibrosis.
In Iowa, there were 447 individuals living with cystic fibrosis in 2024, according to the Cystic Fibrosis Foundation, a lower number in comparison with other states in the Midwest, such as Wisconsin, Minnesota, and Illinois.
According to the foundation, there are 1,148 people living with CF in Illinois and 755 in Minnesota.
The most significant difference many researchers are now seeing, Stotlz said, is the demographic makeup of those living with cystic fibrosis, with more adults than children currently living with cystic fibrosis in the U.S.
Historically, cystic fibrosis had been seen as a primarily pediatric disease, as many weren’t living past the age of 20, Stoltz said.
“Now people are going to live longer and longer… we used to never worry about cancer screenings or risk factor modification for heart disease because people weren’t going to live to the point where cancer was an issue,” Stoltz said.
What is cystic fibrosis?
Ashley Cooney, assistant professor in the pediatrics and pulmonary division at the UI, said cystic fibrosis manifests within the lungs as a result of a lack of chloride ions.
A lack of these ions can cause dehydrated, viscous mucus that remains in the lungs, creating a breeding ground for bacteria and chronic inflammation.
Physical blockage within the lungs due to this mucus can make it difficult to breathe, Cooney said.
One of the primary challenges of cystic fibrosis, Logan noted, is how routine or normal illnesses for individuals living without cystic fibrosis can be life-threatening and dangerous to those living with CF.
“Having a cold, a virus, or getting the flu may cause a healthy person to get knocked down for a week or so, but with CF it is very easy to get knocked down and stay down — and end up being hospitalized,” Logan said.
In February of 2024, Logan was hospitalized for the first time in six years due to an illness she may have picked up from her two young children.
“I only ended up in the hospital for five days, but I’m lucky that it wasn’t longer than that,” Logan said.”When I travel or go to conferences, I still wear a mask regardless of how safe things are.”
The genetic component of cystic fibrosis is important to Logan because she can pass down the CFTR gene to her sons. However, Logan’s husband is not a carrier of the gene, therefore neither of her sons has cystic fibrosis but they still may possess the gene.
As her children get older, Logan said she and her husband are considering genetic testing for their sons so they can be informed about whether they would pass on CF to their own kids in the future.
One of the most common features of cystic fibrosis, Stoltz said, is lung disease, a primary contributor to the morbidity, or the rate of a given disease, and mortality rate in those with cystic fibrosis.
Those who have cystic fibrosis are often prone to lung infections, Stoltz said. These infections are associated with inflammation in the lungs and a buildup of mucus in the airways. This can cause respiratory failure or require a lung transplant.
On Jan. 1, 2024, there were seven individuals awaiting a lung transplant at UI Health Care, according to the Scientific Registry of Transplant Recipients. By December 2024, there were 17 transplants through the hospital’s transplant program.
According to the Health Resources and Services Administration, the number of lungs transplanted in the U.S. in 2024 was 3,340, a significant increase from the previous year, which saw 3,026 transplants.
Stoltz said cystic fibrosis not only causes inflammation and mucus in the lungs but also affects nearly every organ in the body.
Cystic fibrosis can cause gastrointestinal, or GI, issues. These primarily manifest in the form of a bowel obstruction or affect one’s pancreas, Stoltz said.
The pancreas serves two primary functions within the human body: producing pancreatic enzymes to aid in food digestion and regulating endocrine-related issues, such as blood sugar levels.
For some with cystic fibrosis, Stoltz said, those pancreatic enzymes fail to be produced, and endocrine-related issues can lead to the development of diabetes.
The medication changing lives
Trikafta was approved by the Food and Drug Administration in 2019 for individuals aged 12 and older.
In December 2024, Vertex Pharmaceuticals approved the use of Trikafta for individuals aged 2 years or older.
Delta f508 is the most common CFTR mutation, Stoltz said, and is essentially stuck inside the cell. Typically, the CFTR mutation is located on the cell membrane. Trikafta helps the CFTR gene move from inside the cell to the cell surface.
Small molecule treatments, such as Trikafta, benefit people who have modulator-responsive mutations, like delta f508, if they take the drug daily.
Logan, who started being hospitalized once a year for roughly 15 years prior to the emergence of Trikafta, sees the drug as a
“game changer.”
Logan’s primary symptom of living with cystic fibrosis is coughing due to mucus and phlegm buildup. Working out or increasing her heart rate can exacerbate this issue.
“Coughing wears you out a lot, and the sicker you are, the worse it is,” Logan said.
During her pregnancy, Logan developed gestational diabetes because of her increased risk to develop the disease.
One of the therapeutic treatments included in an individual’s cystic fibrosis regimen is the vest, helping to loosen mucus in the lungs by vibrating the upper torso, Cooney said. Nebulizers are devices that deliver a hypertonic saline solution, which can be inhaled to aid with breathing.
“I am very lucky that I know I have minimal need for treatments because of that drug. Prior to that, I was doing the vest machine for 30 minutes a day and taking an hour of nebulizers in the morning and in the evening,” Logan said.
Though Logan and Denison are both able to take Trikafta, the drug is not a cure and isn’t always available to all living with cystic fibrosis.
Working toward advancements
For those who possess a cystic fibrosis mutation that does not respond to small molecule drugs such as Trikafta, Cooney hopes one day these individuals are eligible for genetic therapies, one of which includes Clustered Regularly Interspaced Short Palindromic Repeats, or CRISPR technology.
CRISPR, Cooney said, is an enzyme recognizing a specific sequence of DNA, such as the CFTR gene, that can cut DNA to induce an insertion or a deletion. This then allows for the editing of the sequence.
Roughly 10 to 15 percent of individuals living with cystic fibrosis are ineligible to receive specific drugs due to their specific CFTR mutation, Stoltz said.
This ineligibility, Cooney said, stems from the fact that there are over 200 different mutations of the CFTR gene, all of which are categorized into roughly six classes. Of these classes, the most severe mutations are unable to create a full length gene product, meaning the mutations do not respond to these small scale modulators.
Echoing a similar sentiment, Dension noted how expensive Trikafta is and how many people can’t afford it.
According to the National Library of Medicine, the Trikafta drug costs approximately $300,000 a year.
“I am thankful I am able to be on this drug, but my hope is that someday for me and for other people,” Dension said. “They find a way to no longer have the CFTR gene that causes cystic fibrosis. This drug completely changed my life, so it would mean a lot.”
Support and looking to the future
Denison said though she is an independent person, she finds support not only from her doctors at the hospital, but also through the online cystic fibrosis community.
With cystic fibrosis, Denison said she and others with the disease cannot be within six feet of each other as they can pass bacteria along to one another. As a result, most of Denison’s community and support system is remote.
“It’s a lot of online activities with other people with CF who sometimes don’t actually understand what they’re going through, and you try to explain that to the best of your ability,” Denison said.
The Cystic Fibrosis Foundation gives Denison the opportunity to chat with people her age living with cystic fibrosis in Iowa.
Logan said the foundation runs three programs: virtual conferences such as Breathe Con, Research Con, and CF Circle.
Breathe Con allows those living with cystic fibrosis to share their own, unique experiences with one another without having parents, caregivers, doctors, and others listening.
Research Con is more open, allowing for anyone in the cystic fibrosis community, even those who are not actively living with it, who are interested in learning more about the disease itself.
CF Circle involves a mix of individuals, from those who have cystic fibrosis to family and community members, who wish to have discussion on various topics virtually.
Outside of her “virtual family,” Denison’s care team at UI Health Care have played a key role in her diagnosis.
“Every time I go to the doctor, I see multiple providers, and visits aren’t just one hour — I’m there the entire day,” Denison said
Having a twin brother who is actively living with cystic fibrosis, Denison said, has helped her.
“That has helped a lot because he very much understands, even though everyone’s CF experience is very different from one another,” Denison said.
Logan said there is a need in the community for adults to be able to talk to one another. Through these virtual programs, many have been able to find differing ways to connect.
“They can talk about issues or challenges they are having but also share their celebrations and the hope and good things coming out of medical advancement, things we just never thought were going to be a possibility,” Logan said.
Researchers such as Stoltz and Cooney see these medical advancements as ways to figure out treatments for those who are ineligible for certain types of drugs.
“It’s trying to figure out what type of gene therapy approaches can be done for them and how we can correct the gene,” Stoltz said.
The only drug Logan is currently taking, which she never could have foreseen, for her cystic fibrosis is Trikafta.
“At age 37, the soft age my parents didn’t think I’d make it to, I’m actually as healthy or healthier than I’ve probably ever been,” Logan said.
Logan said with advancements in cystic fibrosis she and many others have had the opportunity to experience things they were told would never be on the table.
“My message is that the work is not done, and we need more support for adults with CF, and I hope that in my lifetime we’ll see a cure, but we just aren’t there yet, so we have to keep pushing,” Logan said.