Specialty pharmaceutical company Forest Laboratories said Wednesday it has agreed to pay $2.9 billion in cash to acquire Aptalis Pharma from the latter’s shareholders, including private equity firm TPG.

TPG acquired Aptalis—which specializes in drug treatments for cystic fibrosis and other gastrointestinal disorders—for $1.3 billion in 2007, when the company was called Axcan Pharma. Axcan’s purchase of Eurand four years later resulted in the company changing its name to Aptalis. The company generated $687.9 million in revenues during the last fiscal year.