Sionna's CF add-on pill fails to improve outcomes in Phase 2 trial with Trikafta

Sionna Therapeutics reported that its experimental cystic fibrosis pill, SION-719, did not provide any additional benefit when combined with Vertex Pharmaceuticals' Trikafta in a Phase 2 study.

The biotech said it will cease development of the drug as an add‑on therapy for CF patients, acknowledging that the trial results do not support further advancement.

In the same announcement, Sionna hinted at possible workforce reductions, noting that the company will take actions to preserve capital while it evaluates its next steps.

The setback comes as the company, founded in 2019, had hoped to build on the market success of Trikafta, which transformed treatment for tens of thousands of CF patients.