FDA updates Trikafta (elexacaftor/tezacaftor/ivacaftor) label: extended age range to 2 years and new drug interaction data
FDA approved a label update for Trikafta (elexacaftor/tezacaftor/ivacaftor; Vertex Pharmaceuticals) expanding its approved use to patients with cystic fibrosis aged 2 years and older who have at least one F508del mutation or a mutation responsive to the regimen. The updated label also includes new CYP3A4 interaction data and revised monitoring guidance for liver function tests in paediatric patients.
Cystic fibrosis (CF) ↗ is an autosomal recessive disorder caused by mutations in the CFTR gene, affecting approximately 40,000 people in the US. The F508del mutation — present in ~90% of patients — causes misfolding and premature degradation of the CFTR chloride channel. CFTR modulators address the underlying protein defect rather than just symptoms. Trikafta combines a corrector (elexacaftor), a potentiator (ivacaftor), and a second corrector (tezacaftor) to restore CFTR to the cell surface and enhance its opening. For mechanism detail, see the GeneReviews CF overview ↗.
Paediatric age expansion: 2 years and older
The previous lower age limit was 6 years for Trikafta's original formulation; an age 2–5 granule formulation received FDA approval in 2023 via supplemental NDA. This label update formalises the consolidated age indication and adds paediatric-specific dosing weight bands (under 14 kg and 14 to under 25 kg). Weight-based dosing for children under 6 years uses a granule formulation mixed with soft foods. The Cystic Fibrosis Foundation clinical guidelines ↗ provide dosing and monitoring recommendations for all age groups.
New CYP3A4 interaction data
The updated prescribing information includes revised warnings for strong CYP3A4 inhibitors (e.g., itraconazole, ketoconazole, clarithromycin) requiring dose reduction to every-other-day dosing, and strong CYP3A4 inducers (e.g., rifampicin, St John's wort) that significantly reduce elexacaftor/tezacaftor/ivacaftor exposure — co-administration is not recommended. New paediatric-specific DDI data are provided for moderate inhibitors. For a full substrate/inhibitor/inducer table see the FDA DDI labelling table ↗.
FAQ
What triggers an FDA label update?
Label updates can be triggered by post-market safety data from the FAERS database ↗, new clinical trial results, manufacturer-initiated reviews, or FDA-directed safety communications. The FDA can require label changes under 21 CFR 314.81 or negotiate them with manufacturers. See the FDA Safety-related Labeling Changes (SrLC) database ↗ for a full history.
Where is the updated label published?
Updated labels are published on DailyMed (NLM) ↗ and Drugs@FDA ↗. DailyMed is typically the most current source, as manufacturers submit label updates there directly.