Nonetheless, if Acceleron Pharma can buy out Celgene before results are announced from the ongoing phase 2 trial in early 2020, and the midstage study corroborates findings from promising animal studies (which often don't hold up in humans), then the company could have another potential blockbuster on its hands. PAH treatments have annual sales of $4 billion in the United States. And since sotatercept works through a unique mechanism of action, it could be combined with existing treatment options, potentially increasing its market potential beyond the existing opportunity.