Forest Laboratories has agreed to pay US$1.2 B upfront, or US$30 per share, in order to acquire Clinical Data, whose novel antidepressant Viibryd™ (vilazodone hydrochloride) received US FDA approval in January 2011 for the treatment of major depressive disorder in adults. Reflecting the uncertainty surrounding the sales potential of the drug, Forest has also agreed to pay up to an additional US$6 per share based upon the achievement of certain commercial milestones in relation to Viibryd. For Forest, the acquisition will partially offset revenue losses following the patent expiry of the company’s antidepressant Lexapro® (escitalopram) in 2012.