Pfizer Inc. (NYSE: PFE) and Trillium Therapeutics Inc. (NASDAQ/TSX: TRIL) today announced that the companies have entered into a definitive agreement under which Pfizer will acquire Trillium, a clinical stage immuno-oncology company developing innovative therapies for the treatment of cancer. Under the terms of the agreement, Pfizer will acquire all outstanding shares of Trillium not already owned by Pfizer for an implied equity value of $2.26 billion, or $18.50 per share, in cash. This represents a 118% premium to the 60-day weighted average price for Trillium.