Vertex halts mRNA cystic fibrosis program citing tolerability concerns

Vertex Pharmaceuticals announced it is ending development of its mRNA-based cystic fibrosis therapy after encountering tolerability problems that echo challenges seen elsewhere in the field.

The Boston-based company said the safety concerns prevented further progress and led to the decision to drop the program.

No timeline or alternative plans were disclosed, and the company did not indicate any immediate impact on its broader pipeline.

The setback highlights the ongoing difficulty of delivering genetic medicines for cystic fibrosis.