Exhibit

We hereby consent to the incorporation by reference in (i) the Registration Statements on Form S-8 (No. 333-217905, 333-205379, 333-146319, 333-139600, 333-123212, and 333-153612) and (ii) the Registration Statement on Form S-3 (No. 333-226838) of Alexion Pharmaceuticals, Inc. of our report dated February 6, 2019 relating to the financial statements and the effectiveness of internal control over financial reporting, which appears in this Form 10-K.