Vertex Pharmaceuticals Incorporated (NASDAQ: VRTX) presented clinical data showing that 65% of children ages 2 to 5 with cystic fibrosis achieved sweat chloride levels below 30 mmol/L when treated with ALYFTREK, according to data presented at the European Cystic Fibrosis Conference.

The Phase 3 open-label study included 67 children with vanzacaftor/tezacaftor/deutivacaftor-responsive genotypes, including those homozygous for the F508del mutation and those with F508del/minimal function mutations. Treatment with ALYFTREK resulted in a mean reduction in sweat chloride of 9.6 mmol/L from baseline through week 24, with 92% of children achieving concentrations below 60 mmol/L.

Vertex plans to submit for global regulatory approvals of ALYFTREK in children ages 2 to 5 in the first half of 2026. The company also presented 96-week interim analyses from two open-label extension studies demonstrating the long-term safety and efficacy profile of ALYFTREK in people with cystic fibrosis ages 6 and older.

Additionally, Vertex presented Phase 3 data on TRIKAFTA in children ages 1 to less than 2 years. The 24-week study of 54 enrolled children showed TRIKAFTA resulted in a mean sweat chloride reduction of 71.8 mmol/L from baseline, with 98% of children achieving concentrations below 60 mmol/L and 68.6% reaching below 30 mmol/L. The company has initiated global regulatory submissions for TRIKAFTA in this age group.

The uses of ALYFTREK in children with cystic fibrosis ages 2 to 5 and TRIKAFTA in children ages 1 to less than 2 are investigational and not yet approved.