Jason is a general assignment reporter, with particular focus on genetic medicine and rare disease. Sionna Therapeutics said Monday that its experimental pill for cystic fibrosis did not show any benefit when added onto Vertex Pharmaceuticals’ Trikafta in a Phase 2 trial. The company will no longer try to advance the drug, called SION-719, as an add-on therapy for CF patients. And it hinted at potential layoffs, saying it will “take actions to preserve capital while evaluating next steps.” AdvertisementSionna’s stock fell 90% in pre-market trading Monday morning.