Vertex Presents New ALYFTREK® Data at the European Cystic Fibrosis Conference
Vertex Pharmaceuticals Incorporated (Nasdaq: VRTX) has announced new clinical and long-term follow-up data highlighting the expanding impact of its cystic fibrosis (CF) treatment portfolio, particularly ALYFTREK® (vanzacaftor/tezacaftor/deutivacaftor), across very young pediatric populations as well as older children and adults. The findings, presented at the European Cystic Fibrosis Conference, underscore continued advances in CFTR modulator therapy and reinforce the potential of early intervention to meaningfully alter disease progression.
The dataset includes results from a Phase 3 study evaluating ALYFTREK in children aged 2 to 5 years, alongside 96-week interim analyses from two open-label extension studies in patients aged 6 to 11 years and those aged 12 years and older. Additional Phase 3 data were also presented for TRIKAFTA® (elexacaftor/tezacaftor/ivacaftor) in infants aged 12 to less than 24 months. Together, these datasets provide a comprehensive view of both short- and long-term outcomes across a wide age range of people living with CF.
Advancing Early Treatment in Young Children Aged 2 to 5 Years
A central focus of Vertex’s presentation was the Phase 3 open-label study of ALYFTREK in 67 children aged 2 to 5 years with cystic fibrosis and vanzacaftor/tezacaftor/deutivacaftor-responsive genotypes. This included children homozygous for the F508del mutation (F/F) as well as those carrying F508del/minimal function (F/MF) mutations.
Over the 24-week treatment period, ALYFTREK demonstrated a favorable safety and tolerability profile consistent with prior studies. Safety was the primary endpoint of the trial, and no new or unexpected safety signals were observed.
Beyond safety, the study showed clinically meaningful improvements in cystic fibrosis transmembrane conductance regulator (CFTR) function, as measured by sweat chloride (SwCl) levels. Patients previously receiving TRIKAFTA at baseline experienced an additional mean reduction in SwCl of -9.6 mmol/L (95% CI: -12.1 to -7.0) following initiation of ALYFTREK. This reduction reflects improved CFTR protein function, which is central to disease pathology in CF.
At Week 24, 92% of children achieved sweat chloride levels below 60 mmol/L, the diagnostic threshold for cystic fibrosis. Notably, 65% of children reached levels below 30 mmol/L, a benchmark associated with near-normal CFTR function and values typically observed in healthy carriers of CFTR mutations. According to Vertex, these results represent some of the most robust improvements in CFTR function observed in this pediatric age group with any modulator therapy to date.
Clinical Significance of CFTR Restoration
The importance of sweat chloride reduction as a biomarker of disease correction was emphasized by Vertex leadership. According to Dr. Carmen Bozic, Executive Vice President of Global Medicines Development and Medical Affairs and Chief Medical Officer at Vertex, ALYFTREK represents a significant advancement in the company’s long-standing goal of restoring CFTR function in people with cystic fibrosis.
She noted that the majority of children aged 2 to 11 treated with ALYFTREK achieved sweat chloride levels below 30 mmol/L, a level associated with near-normal CFTR activity. This milestone is particularly meaningful because it suggests a degree of biological correction that approaches the physiological range seen in healthy individuals who carry one CFTR mutation but do not develop disease.
The data reinforce the importance of early and sustained CFTR modulation, particularly in young children whose organs are still developing and may be more responsive to treatment.
Clinical Experience and Real-World Perspective
The clinical significance of these findings was further supported by Professor Marcus A. Mall, a leading pediatric respiratory specialist and cystic fibrosis expert at Charité Universitätsmedizin Berlin. He highlighted his experience treating patients enrolled in the ALYFTREK pediatric program and observed meaningful improvements not only in sweat chloride levels but also in other disease-related markers, including exocrine pancreatic function.
Professor Mall emphasized that early CFTR modulation appears to have the potential to alter disease trajectory when initiated in very young patients. He noted that the growing body of evidence supports the rationale for treating cystic fibrosis as early as possible in life to maximize long-term health outcomes and preserve organ function.
Long-Term Data: Sustained Safety and Efficacy
In addition to pediatric findings, Vertex presented 96-week interim analyses from two open-label extension studies evaluating ALYFTREK in older patient populations, including children aged 6 to 11 years and individuals aged 12 years and older.
These long-term data demonstrated that ALYFTREK continues to exhibit a consistent safety profile over nearly two years of treatment, with no new safety concerns emerging. The efficacy data further supported sustained improvements in CFTR function, reinforcing the durability of treatment response over time.
The results add to a growing evidence base suggesting that highly effective CFTR modulators can provide long-term disease stabilization and potentially modify the underlying progression of cystic fibrosis.
Expanding Evidence for TRIKAFTA in Infants
Vertex also presented new Phase 3 data for TRIKAFTA in children aged 12 to less than 24 months, further expanding the understanding of CFTR modulation in the earliest stages of life. The 24-week, open-label study enrolled 54 infants and evaluated safety and changes in sweat chloride levels as key outcomes.
TRIKAFTA was generally well tolerated in this very young population, with a safety profile consistent with previous studies in older age groups. Importantly, treatment resulted in a rapid and substantial reduction in sweat chloride levels, with a mean decrease of -71.8 mmol/L from baseline in untreated patients.
At Week 24, 98% of infants achieved sweat chloride levels below 60 mmol/L, and 68.6% reached levels below 30 mmol/L. These findings indicate a strong pharmacodynamic response and suggest that CFTR function can be significantly improved even in the first years of life.
Broader Implications for CF Treatment Paradigm
The combined data presented across ALYFTREK and TRIKAFTA studies highlight a rapidly evolving treatment landscape in cystic fibrosis, where early and sustained CFTR modulation is increasingly central to disease management. The ability to achieve near-normal sweat chloride levels in a substantial proportion of pediatric patients suggests that the underlying biological defect driving cystic fibrosis can be significantly corrected with current therapies.
Vertex noted that it plans to submit global regulatory applications for ALYFTREK in children aged 2 to 5 years in the first half of 2026. In parallel, the company has already initiated regulatory submissions for TRIKAFTA in children aged 1 to less than 2 years, reflecting a continued push toward earlier intervention.
A Decades-Long Mission Nearing a New Milestone
According to Vertex, these results represent a pivotal moment in its long-standing mission to develop medicines that restore CFTR function in people living with cystic fibrosis. The company emphasized that the latest data bring it closer to addressing CF at its earliest stages of life, with the goal of preventing irreversible organ damage and improving long-term outcomes.
As CFTR modulators continue to demonstrate increasingly robust and durable effects across multiple age groups, the focus of cystic fibrosis care is shifting toward early diagnosis, early treatment initiation, and sustained management beginning in infancy and early childhood.
Taken together, the ALYFTREK and TRIKAFTA datasets presented at the European Cystic Fibrosis Conference reinforce the transformative potential of CFTR modulation and mark continued progress toward fundamentally altering the course of cystic fibrosis across the lifespan.
