Except with regards to the Prior Confidentiality Agreements, the Legal Activities Letter Agreement, and except with regards to the provisions of the Original Agreement that, by the terms of the Original Agreement, survive the termination of the Original Agreement, it is understood and agreed between Momenta and Baxalta that this Agreement constitutes the entire agreement, both written and oral, between the Parties with respect to the subject matter hereof, and that all prior agreements respecting the subject matter hereof, whether written or oral, expressed or implied, shall be of no force or effect. No amendment or change hereof or addition hereto shall be effective or binding on either of the Parties hereto unless reduced to writing and executed by the respective duly authorized representatives of Momenta and Baxalta.