A Phase 1/2, Multicenter Study Evaluating the Safety, Tolerability, and Biodistribution of RCT2100 with Single- Ascending Doses in Healthy Participants and Multiple- Ascending Doses and Proof-of-Concept in Participants with Cystic Fibrosis

A new drug called RCT2100 is being tested in people with cystic fibrosis to see if it can safely reach and treat the damaged lungs. Cystic fibrosis is caused by faulty genes that make the lungs clog up with thick mucus, leading to repeated infections and eventual respiratory failure. There is no cure. Current treatments manage symptoms but do not fix the underlying genetic defect. This trial tests whether RCT2100 can deliver a corrected copy of the faulty CFTR gene directly to lung cells, potentially restoring their normal function. If the drug proves safe and effective, it could become the first treatment to address the root cause of cystic fibrosis rather than just its symptoms. For patients, that could mean fewer lung infections, less reliance on daily physiotherapy and medications, and a longer life expectancy. The trial is still in early phases—it first checks safety in healthy volunteers, then moves to patients—so a practical treatment remains years away. But if successful, this approach could also be adapted for other genetic lung diseases, changing how such conditions are treated.