Vertex Reports Strong ALYFTREK Results in Young Children With Cystic Fibrosis

Vertex Pharmaceuticals presented new Phase 3 data at the 2026 European Cystic Fibrosis Conference demonstrating the impact of ALYFTREK (vanzacaftor/tezacaftor/deutivacaftor) in children aged 2 to 5 years with cystic fibrosis (CF). The open‑label study enrolled 67 children with responsive genotypes, including F508del homozygous (F/F) and F508del/minimal function (F/MF) mutations. All participants completed 24 weeks of treatment. The study met its primary endpoint of safety and tolerability, with ALYFTREK showing a safety profile consistent with previous studies and no new safety signals.

CFTR Function Restoration

Treatment with ALYFTREK produced an additional mean sweat chloride reduction of 9.6 mmol/L from an already optimized TRIKAFTA baseline, indicating further restoration of CFTR function beyond current standard‑of‑care therapy. By Week 24, 92% of children achieved sweat chloride concentrations below 60 mmol/L, the diagnostic threshold for CF, while 65% reached levels below 30 mmol/L. Sweat chloride levels below 30 mmol/L are comparable to the median values observed in healthy CFTR mutation carriers and are considered a key marker of near‑normal CFTR function. Vertex noted that these outcomes exceeded those reported with earlier CFTR modulators in this age group.

Long‑Term Extension Data

Interim analyses from ongoing open‑label extension studies (NCT05844449) in children aged 6 to 11 years and patients aged 12 years and older reinforced ALYFTREK’s durability. Results through 96 weeks showed sustained efficacy alongside a favorable long‑term safety profile, supporting the therapy’s potential for chronic use across pediatric and adult populations.

TRIKAFTA Expansion into Infants

Vertex also reported Phase 3 (NCT05882357) results in 54 children aged 12 to less than 24 months treated with TRIKAFTA (elexacaftor/tezacaftor/ivacaftor). The regimen was generally safe and well tolerated, producing a mean sweat chloride reduction of 71.8 mmol/L from baseline. By Week 24, 98% of treated infants achieved sweat chloride levels below 60 mmol/L, and 68.6% reached levels below 30 mmol/L. These findings support expansion of TRIKAFTA into children as young as 1 year.

Clinical Perspectives

Chief Medical Officer Dr. Carmen Bozic highlighted that ALYFTREK is the first therapy to bring the majority of children aged 2 to 11 years below the 30 mmol/L threshold, underscoring its potential to normalize CFTR activity. She noted that the findings move Vertex closer to its long‑term goal of restoring CFTR function across the broad cystic fibrosis population.

Professor Marcus Mall of Charité Universitätsmedizin Berlin said the results strengthen the rationale for initiating highly effective CFTR modulation as early as possible in the disease course, citing improvements in CFTR function and markers of pancreatic health.

Clinical and Regulatory Outlook

Vertex plans to initiate global regulatory submissions for ALYFTREK in children aged 2 to 5 years during the first half of 2026. The company has already begun submissions for TRIKAFTA in children aged 1 to less than 2 years, advancing a staged strategy to extend highly effective CFTR modulation across all pediatric age groups.

If approved, the expanded pediatric indications would extend highly effective CFTR modulation to some of the youngest patients living with cystic fibrosis and further broaden access to disease‑modifying treatment across the CF population.

Reference

Vertex Presents New Data on ALYFTREK® at European Cystic Fibrosis Conference | Vertex Pharmaceuticals Newsroom