Sionna Therapeutics announced it is laying off 46% of its workforce as it pivots after an unexpected failure of a cystic fibrosis trial. The company said the workforce reduction is part of its strategic shift to realign programs and resources following the negative result. The move reflects how quickly capital and headcount planning can change for clinical-stage biotechs after late-breaking clinical outcomes, particularly when a program was considered closely watched. Sionna’s restructuring indicates a near-term focus on identifying a viable path forward in cystic fibrosis and managing the internal pipeline through reduced burn.