FDA approves Vertex’s Alyftrek and Trikafta label extensions for cystic fibrosis treatment

Vertex Pharmaceuticals has received US FDA approval for label extensions of both Alyftrek (vanzacaftor/tezacaftor/ivacaftor) and Trikafta (elexacaftor/tezacaftor/ivacaftor), expanding access to cystic fibrosis (CF) treatment to approximately 95% of all people with CF in the United States, the company said. The expansions bring approximately 800 additional people with CF in the US into eligibility for a CFTR modulator for the first time, representing a further step in Vertex’s decades-long effort to reach patients across the full spectrum of CFTR gene variants.

The US FDA approved expanded use of Alyftrek for people with CF aged 6 and older who carry a variant in the CFTR gene that is either responsive based on clinical and/or in vitro data, or that results in production of CFTR protein — regardless of where in the CFTR protein the variant is located. The indication for Trikafta was simultaneously expanded for patients aged 2 and older under comparable criteria. The key regulatory distinction in this expansion is the inclusion of any protein-producing variant to both drugs’ labels, a broader formulation than prior mutation-specific or class-specific eligibility criteria.

The label expansions were supported by clinical and/or in vitro data from 564 CFTR variants demonstrating response to Alyftrek and 521 variants demonstrating response to Trikafta, the company said. The source data does not specify the names or identifiers of the pivotal clinical trials underpinning this submission, and detailed trial-level efficacy endpoints are not available from the provided materials. Both products carry a boxed warning for drug-induced liver injury and liver failure; cases of liver failure leading to transplantation and death have been reported with Trikafta in both clinical trial and post-marketing settings. Liver function monitoring is required for both medicines throughout treatment.

Cystic fibrosis is a rare, progressive genetic disease affecting more than 112,000 people globally, including approximately 97,000 in the US, Europe, Australia, and Canada, according to Vertex. The disease is caused by mutations in the CFTR gene that lead to defective or absent CFTR protein, producing abnormally thick mucus in the lungs and other organs, chronic infections, and organ damage. The median age of death remains in the 30s, though projected survival has been improving with the advent of CFTR modulator therapy. Prior to the current label expansions, Vertex’s modulator medicines were already treating over 75,000 people across more than 60 countries — approximately two-thirds of the diagnosed CF population eligible for this class of treatment.

The significance of this approval for the remaining untreated population lies in the heterogeneity of CFTR mutations. CF is caused by hundreds of distinct genetic variants, the majority of which have historically fallen outside the scope of approved modulator labels. By extending eligibility to any variant that produces CFTR protein, the updated Alyftrek indication moves away from a mutation-by-mutation approval framework toward a broader protein-based criterion. This approach, supported by a combination of in vitro assay data and clinical evidence across 564 variants, reflects an evolution in how regulators and developers are approaching rare disease populations defined by genetic diversity rather than a single dominant mutation.

Vertex holds a dominant position in the CFTR modulator field, with Trikafta having been first approved in October 2019 and Alyftrek receiving its initial approval more recently as a once-daily alternative. The two products differ in their component molecules — Alyftrek substitutes vanzacaftor and deutivacaftor for elexacaftor and ivacaftor respectively — and in dosing schedule, with Alyftrek designed for once-daily administration compared to Trikafta’s twice-daily regimen. Vertex also markets the earlier brands Symdeko (tezacaftor/ivacaftor), Orkambi (lumacaftor/ivacaftor), and Kalydeco (ivacaftor).

The label expansions for Alyftrek and Trikafta further consolidate Vertex’s dominance across the CF treatment landscape by extending next-generation triple-combination therapies to a broader set of rare CFTR variants, potentially accelerating the obsolescence of older dual-combination and monotherapy regimens such as Symdeko, Orkambi, and Kalydeco. While these earlier agents remain relevant for specific mutation subsets and pediatric populations, the shift toward broader, protein-based eligibility criteria reinforces the clinical and commercial centrality of Vertex’s newer regimens and narrows the residual untreated population to patients without CFTR protein production.

The approximately 5% of CF patients in the US who remain ineligible following this expansion are those whose CFTR mutations do not result in any protein production — a group for whom modulator-based approaches are not currently viable and where alternative therapeutic strategies, including gene therapy and mRNA-based approaches, represent the primary area of ongoing research interest, though no such therapies are referenced as approved or near-approval in the provided data.