The Final 10%: Gene Therapy and mRNA Research

Our last post covered how CFTR modulators reshaped cystic fibrosis care, and the roughly one in ten patients whose mutations those drugs cannot address. For that group, research is aimed at a different mechanism. Instead of improving the function of a defective protein, the goal is to deliver the instructions for a functional protein directly to the cells that need it.

Two approaches account for much of the current work.

The first is mRNA therapy. The concept is to deliver messenger RNA, the working template for building functional CFTR protein, to the epithelial cells lining the airways. The cells translate that template and produce the protein themselves. Because the therapy supplies a functional workaround rather than repairing the underlying gene, it is mutation-agnostic in principle, meaning it could apply regardless of a patient's specific mutation. The leading candidate, VX-522, is an inhaled mRNA therapy developed by Vertex in collaboration with Moderna, and it was in early-phase (Phase 1/2) clinical trials as of early 2026.

The second is gene therapy and gene editing, which aim to correct or replace the defective gene itself for a durable, potentially one-time result. The technical barriers are substantial: delivering the therapy to the correct airway cells, achieving durable expression, and doing so safely. As of early 2026 this work remains largely preclinical and earlier-stage than the modulator or mRNA programs, with long timelines ahead.

These are the approaches most likely to reach patients for whom modulators offer nothing. The work is slow, expensive, and uncertain, and it is the path toward a treatment option for every person with CF rather than most of them.

That is what donor funding supports.