Celldex Therapeutics, Inc. Enhances Precision Targeted Immunotherapy Platform with the Acquisition of CuraGen Corporation Conference call scheduled for Friday

Celldex Therapeutics, Inc. Enhances Precision Targeted

Immunotherapy Platform with the Acquisition of CuraGen Corporation

Conference call scheduled for Friday, May 29, 2009 at 8:30 AM ET

Transaction adds 11 oncology-focused antibodies,

including CR011, to expand Celldex s Precision Targeted Immunotherapy Platform

Increases potential value of both CuraGen and

Celldex assets through combined technologies and intellectual property

Increases Celldex s pro forma cash to an

expected $96 million at close; extends cash resources into 2012

NEEDHAM, MA and BRANFORD, CT (May 29, 2009): Celldex Therapeutics, Inc.

(Nasdaq: CLDX) today announced it has entered into a definitive agreement to

acquire CuraGen Corporation (Nasdaq: CRGN). The acquisition will add a

portfolio of oncology-focused, fully-owned antibodies to Celldex s Precision

Targeted Immunotherapy Platform. Celldex will acquire CuraGen in a tax-free

stock-for-stock transaction, which values CuraGen at approximately $94.5

million, subject to certain adjustments described within the definitive

agreement. In addition to its pipeline, CuraGen is expected to have a cash

balance of at least $54.5 million net of certain acquisition-related costs and

CuraGen convertible debt at the transaction s close, which is anticipated to

occur in the third quarter of 2009. Concurrent with the closing of the

transaction, Dr. Timothy Shannon, President and Chief Executive Officer of

CuraGen, will join the Celldex Board of Directors.

Anthony Marucci, President and Chief Executive Officer of Celldex,

stated, The CuraGen acquisition fulfills a major initiative to identify,

acquire and integrate value-creating, synergistic assets to fuel our Precision Targeted Immunotherapy

antibody-based technology pipeline. In addition, this acquisition

further strengthens Celldex s intellectual property estate and balance sheet,

providing cash resources to advance our clinical development programs into 2012. Further, on behalf of the Celldex

board and management team, I d like to welcome Tim to our Board of Directors.

We believe this transaction represents a combination that clearly exceeds the

Shannon, M.D., President and Chief Executive Officer of CuraGen, commented, CuraGen s

Board of Directors considered a range of strategic alternatives to increase

shareholder value and concluded that this transaction represents the best

opportunity for our shareholders. We believe Celldex s immunotherapy expertise

and platform technology provide an excellent fit for our antibody portfolio,

industry collaborations, technological assets and intellectual property. The

deal also offers CuraGen investors reduced risk via ownership of a broader

portfolio, while still retaining upside potential of CR011 in the combined

Corporation has a portfolio of 11 fully-owned, human antibodies that the

Company selected, optimized and advanced during its collaboration with Abgenix

(acquired by Amgen). CR011, currently in Phase 2 studies, is an antibody-drug

conjugate that targets GPNMB, a protein that is highly expressed in metastatic

breast cancer and melanoma. CR011 has shown promising early evidence of

anti-tumor activity, including objective tumor responses, in patients with

breast cancer and unresectable stage III and IV melanoma.

expertise in developing novel antibody-based therapeutics will enable us to

seamlessly integrate CuraGen s antibody programs into our Precision Targeted

Immunotherapy Platform and selectively identify and advance the candidates we

hold the most therapeutic promise, said Thomas Davis, M.D., Chief Medical

Celldex Therapeutics is discovering and developing innovative targeted

immunotherapeutics for the treatment of cancer, infectious and inflammatory

diseases. The Company s focus is on the use of tumor-specific targets and human

monoclonal antibodies to precisely deliver therapeutic agents through their

novel targeted immunization approach. Celldex s deep pipeline consists of

product candidates in varying stages of development, with lead candidate

CDX-110, partnered with Pfizer, currently undergoing evaluation in a Phase 2

clinical trial in newly diagnosed glioblastoma multiforme (GBM) and CDX-1307,

currently enrolling in a Phase 1 study in epithelial tumors. In addition, the

Company recently completed the successful preclinical development of CDX-1401,

a candidate for study in multiple solid tumors.

acquisition of CuraGen adds to Celldex s clinical development program a number

of important milestones anticipated over the next 12 to 18 months including:

Under the terms of the

definitive agreement, Celldex will acquire CuraGen in a tax-free

stock-for-stock transaction, representing an equity value of approximately

$94.5 million. The purchase price payable in this transaction is subject to

certain adjustments described within the definitive agreement, including a

collar of between 32.5% and 58% of Celldex s outstanding common stock. The

transaction, which is subject to the receipt of CuraGen and Celldex stockholder

approvals and other customary closing conditions, is expected to be completed

in the third quarter of 2009.

CuraGen is expected to

deliver $68.6 million in cash, net of acquisition-related costs, including

transaction fees and severance payments and a closing balance sheet adjustment.

At the close of the transaction, Celldex will assume $14.1 million of CuraGen s

4% convertible debt due in February 2011, resulting in an expected $54.5

million of net cash. The Boards of Directors of each of Celldex and CuraGen

have approved the transaction and unanimously recommended that their

stockholders approve the transaction.

Celldex was advised by WBB

Securities, LLC, Brean Murray, Carret & Co., LLC and Lowenstein

Sandler PC. CuraGen was advised by Piper Jaffray & Co. and Wilmer

Cutler Pickering Hale and Dorr LLP.

Conference Call Information

A joint conference call will

be held on Friday, May 29, 2009 at 8:30 AM ET to discuss the proposed

acquisition. The conference call may be accessed by visiting

or www.curagen.com. The webcast and telephonic replay will be available

following the filing of the conference call transcript with the SEC.

Callers may also access the

call with the following dial-in information:

Celldex Therapeutics, Inc.

Therapeutics (Nasdaq: CLDX) is an

integrated biopharmaceutical company that applies its comprehensive Precision