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Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

        We hereby consent to the incorporation by reference in the Registration Statements on Form S-8 (File Nos. 333-151728 and 333-117602) and on Form S-3 (File No. 333-143112) of Celldex Therapeutics, Inc. (formerly known as AVANT Immunotherapeutics, Inc.) of our report dated March 2, 2009 relating to the financial statements and the effectiveness of internal control over financial reporting, which appears in this Form 10-K.

/s/ PricewaterhouseCoopers LLP

Boston, Massachusetts
March 2, 2009

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Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM