Proteostasis Therapeutics (PTI): results from the Phase 2 study

Shares of Proteostasis Therapeutics  fell on Tuesday after the biopharmaceutical company shared mixed findings from a mid-stage study for its experimental triple combination cystic fibrosis therapy. Proteostasis still plans to launch a Phase 3 trial next year. It is also conducting a personalized medicine study for patients with cystic fibrosis. The company held a call with investors on Tuesday morning to discuss the findings. Shares of Proteostasis have gained 34% year-to-date, while the S&P 500 (SPX) is up 27%.