The Baupost purchase of Facet Biotech's Rights

STOCKHOLDERS AGREEMENT

This STOCKHOLDERS AGREEMENT, dated as of December 16, 2009, is between Facet Biotech Corporation, a Delaware corporation (the “Company”), and The Baupost Group, L.L.C., SAK Corporation and Seth A. Klarman (collectively, the “Baupost Entities”).

RECITALS:

WHEREAS, as of the date hereof, the Baupost Entities Beneficially Own (as defined below) an aggregate of 3,506,875 shares of common stock, par value $0.01 per share, of the Company (“Common Stock”), including the associated rights to purchase shares of Series A Preferred Stock of the       Company (“Rights”) issued pursuant to the Rights Agreement (as defined below), which represents approximately 14.0% of the shares of Common Stock outstanding as of the date hereof;

WHEREAS, pursuant to the terms of the Rights Agreement, the Rights will become exercisable under certain circumstances, including if a person becomes an Acquiring Person (as defined in the Rights Agreement) by acquiring Beneficial Ownership (as defined below) of 15% or more of the outstanding shares of Common Stock; and

WHEREAS, the Baupost Entities desire to have the ability to purchase additional shares of Common Stock and have requested that the Company amend the terms of the Rights Agreement so as to permit the Baupost Entities to purchase such shares without causing the Rights to become exercisable, and the Board has determined that it is in the best interest of the Company’s stockholders to enter into such an amendment;