Rival's cystic fibrosis drug fails, Vertex shares gain

Sionna Therapeutics said on August 10 that its cystic fibrosis add-on candidate SION-719, designed to be paired with Vertex's Trikafta, missed the primary endpoint in its Phase 2a trial and halted the program. The failure removed one of the most closely watched competitive threats to Vertex's dominant CF franchise, and Vertex shares rose roughly 7-9% intraday on the news.