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.”

Monday’s results are a major blow to Sionna. The company was founded in 2019, the same year that Trikafta reached the market, changing the lives of tens of thousands of CF patients and earning Vertex billions of dollars.