The effects lasted over the entire one-year study period
For the roughly 8,000 people living with cystic fibrosis in Germany, breath has long been a daily negotiation with a body that works against itself. A year-long study by researchers at Charité and the Max Delbrück Center in Berlin now confirms that a triple drug combination — elexacaftor, tezacaftor, and ivacaftor — sustains its improvements in lung function without retreat, offering not a cure, but a more durable truce with a disease that has never offered easy terms. The finding places medicine one careful step closer to the hope of intervening early enough to spare the next generation the accumulated damage that no drug, however promising, can yet undo.
- Cystic fibrosis turns the body's own secretions into a slow siege — thick mucus clogs airways, invites chronic infection, and shortens lives, with 150 to 200 children born into this reality in Germany each year.
- Earlier treatments showed promise but faltered, with bacterial loads rebounding once therapy effects waned — a pattern that eroded confidence in any claim of lasting progress.
- The Berlin research team tracked 79 adolescents and adults over twelve months, measuring whether the triple therapy's gains in mucus fluidity and reduced inflammation would hold — and they did, without the dreaded bacterial rebound.
- The drugs reach roughly 90 percent of CF patients by targeting the most common genetic defect, but the remaining 10 percent are still without options, and even those who benefit carry irreversible lung damage the therapy cannot repair.
- Researchers are now pushing in two directions at once: treating children earlier to prevent chronic damage from forming, and developing new molecular therapies for patients whose genetic profiles place them beyond the current treatment's reach.
A year-long study published in the European Respiratory Journal by scientists at Charité and the Max Delbrück Center in Berlin has confirmed that a three-drug combination — elexacaftor, tezacaftor, and ivacaftor — maintains its benefits in cystic fibrosis patients over twelve months. Airway mucus became less viscous, lung inflammation decreased, and bacterial infection did not rebound — a meaningful distinction from earlier therapies that had shown initial promise before losing ground.
Cystic fibrosis is a hereditary disease in which faulty salt and water transport causes the body to produce thick, sticky secretions that accumulate in the lungs and other organs. In Germany, around 8,000 people live with the condition, and 150 to 200 children are born with it annually. Despite decades of treatment advances, life expectancy remains significantly shortened.
The research team, led by Prof. Marcus Mall, examined sputum samples from 79 adolescents and adults with chronic lung disease over the course of a year. The drugs work by correcting the underlying protein defect responsible for the salt and water imbalance, restoring moisture to the airways and reducing the adhesive properties of mucus. But Mall was measured in his optimism: the therapy cannot reverse the scarring and deterioration that accumulates over years of living with the disease, and patients with advanced damage still require inhaled medications, antibiotics, and physical therapy.
The treatment is effective for roughly 90 percent of CF patients — those carrying the most common genetic variant, F508del — but leaves about 10 percent without a comparable option. Researchers are now pursuing earlier intervention in young children to prevent chronic lung changes before they develop, while also working to create new therapies for patients whose mutations fall outside the current drug's reach. The triple combination has been available in Europe since August 2020 and approved for children as young as six since early 2022. For a disease defined by relentless progression, the confirmation that these gains do not fade over time is, if not a cure, a genuinely durable form of progress.
Cystic fibrosis patients who took a combination of three drugs—elexacaftor, tezacaftor, and ivacaftor—experienced sustained improvements in their lung function over a full year, according to research published this week in the European Respiratory Journal by scientists at Charité and the Max Delbrück Center in Berlin. The mucus in their airways became less viscous. Inflammation and bacterial infection in the lungs decreased. And crucially, these gains held steady throughout the study period, without the rebound in bacterial load that had plagued earlier treatments.
The disease itself is unforgiving. Cystic fibrosis is a hereditary condition in which the body's salt and water transport goes awry, causing patients to produce thick, sticky secretions that accumulate in the lungs, pancreas, and intestines. In Germany alone, roughly 8,000 people live with the disease, and 150 to 200 children are born with it each year. The thick mucus clogs airways, makes breathing harder, and creates an environment where chronic bacterial infections take hold. Life expectancy remains significantly shortened despite decades of treatment advances.
Two years ago, the same research team led by Prof. Marcus Mall demonstrated that the three-drug combination worked in a large portion of CF patients, improving both lung function and quality of life. Now they wanted to know whether those benefits lasted. They examined sputum samples from 79 adolescents and adults with cystic fibrosis and chronic lung disease over twelve months. What they found was encouraging: the mucus became less sticky because the drugs helped restore proper water balance and reduced the adhesive properties of the mucin molecules that form mucus. The inflammation markers dropped and stayed down.
"This is a major step forward in treating cystic fibrosis," Mall said. But he was careful not to overstate the case. The drugs do not reverse the chronic lung damage that accumulates over years of living with the disease. Patients with advanced lung disease still need to inhale mucus-thinning medications, take antibiotics, and undergo physical therapy. The treatment addresses the underlying molecular defect—the faulty protein that causes the salt and water imbalance—but it cannot undo years of scarring and deterioration.
The therapy is available to roughly 90 percent of CF patients because it targets the most common genetic variant, F508del. But that leaves about 10 percent without access. The researchers are now pursuing two parallel paths: starting the triple combination therapy earlier, in early childhood, with the hope of preventing chronic lung changes before they take root; and developing new molecular treatments for patients whose genetic mutations fall outside the F508del category. They are also investigating new drugs that thin and loosen mucus more effectively—work that could eventually help patients with other chronic lung diseases like asthma and COPD.
The triple combination became available in Europe in August 2020 and was approved for children as young as six years old in early 2022. The current study, spanning a full year, shows that the benefits do not fade. For a disease that has long meant a shortened life and constant struggle to clear the lungs, that sustained improvement represents real progress—even if it is not yet a cure.
Notable Quotes
This is a major step forward in treating cystic fibrosis. At the same time, it would be premature to say that patients have been normalized, let alone cured.— Prof. Marcus Mall, Charité
The effects lasted over the entire one-year study period. This is really important because previous medications caused a rebound in the bacterial load in the airways.— Dr. Simon Gräber, Charité
The Hearth Conversation Another angle on the story
Why does the mucus in cystic fibrosis become so sticky in the first place?
It's a problem with how salt and water move across the body's mucosal surfaces. Without enough water in the mucus, and with the mucin molecules sticking to each other too strongly, you get this thick, gluey secretion that clogs the airways.
And the three drugs—how do they fix that?
They work on the underlying protein defect that causes the salt and water imbalance. By correcting that, they allow the mucus to become less viscous and the lungs to clear more easily. It's addressing the root problem, not just treating the symptom.
The study lasted a year. Why is that duration important?
Because earlier treatments would cause a rebound—the bacteria would come roaring back once the drug wore off. This combination held steady for the entire twelve months. That's the difference between a temporary fix and something that actually works long-term.
But you said the drugs don't cure the disease. What can't they fix?
The chronic damage that's already happened. If someone has lived with cystic fibrosis for years, their lungs have scarring and structural changes that no drug can reverse. The combination therapy prevents new damage and manages the disease, but it doesn't undo the past.
What about the patients who can't use this treatment?
About one in ten CF patients have genetic mutations outside the most common type. The researchers are working on new molecular therapies for them, but right now they're left behind. That's why the next frontier is treating children early, before damage accumulates, and expanding the toolkit for everyone else.