Proteostasis Therapeutics (PTI) is developing a combination therapy for cystic fibrosis that is ready to enter Phase 3 trials. The cystic fibrosis space has gotten a lot more competitive over the last few years as Vertex Pharmaceuticals (VRTX) has released several combination therapies that netted it about $4 billion in 2019. Proteostasis will have a tough challenge distinguishing its therapies from Vertex's, but the reward for success is clear, especially given that Proteostasis' current market cap is only about $90 million. In this article, I will describe how Proteostasis might be able to differentiate its